Initial commit.

eslint.config.js

@@ -32,10 +32,10 @@ export default defineConfig({
     "@stylistic": stylisticTs
   },
   rules: {
+    "react-hooks/rules-of-hooks": "error",
+    "react-hooks/exhaustive-deps": "warn",
     "react-refresh/only-export-components": [
       "warn",
-      // Many components are exported as withTranslation()(Component); without
-      // this the rule cannot tell the HOC's result is still a component.
       { allowConstantExport: true, extraHOCs: ["withTranslation"] }
     ],
     "@typescript-eslint/no-explicit-any": "off",

src/components/AppLayout.tsx

@@ -13,41 +13,38 @@ type AppLayoutInternalProps = {
   modals?: React.ReactNode
 } & WithTranslation;
 
-class AppLayoutInternal extends React.Component<AppLayoutInternalProps> {
+const AppLayoutInternal: React.FC<AppLayoutInternalProps> = (props) => {
+  document.body.dir = props.i18n.dir();
 
-  render() {
-    document.body.dir = this.props.i18n.dir();
-
-    return <IconContext.Provider value={{size: "14px"}}>
-      <div className="maputnik-layout">
-        {this.props.toolbar}
-        <div className="maputnik-layout-main">
-          {this.props.codeEditor && <div className="maputnik-layout-code-editor">
-            <ScrollContainer>
-              {this.props.codeEditor}
-            </ScrollContainer>
-          </div>
-          }
-          {!this.props.codeEditor && <>
-            <div className="maputnik-layout-list">
-              {this.props.layerList}
-            </div>
-            <div className="maputnik-layout-drawer">
-              <ScrollContainer>
-                {this.props.layerEditor}
-              </ScrollContainer>
-            </div>
-          </>}
-          {this.props.map}
-        </div>
-        {this.props.bottom && <div className="maputnik-layout-bottom">
-          {this.props.bottom}
+  return <IconContext.Provider value={{size: "14px"}}>
+    <div className="maputnik-layout">
+      {props.toolbar}
+      <div className="maputnik-layout-main">
+        {props.codeEditor && <div className="maputnik-layout-code-editor">
+          <ScrollContainer>
+            {props.codeEditor}
+          </ScrollContainer>
         </div>
         }
-        {this.props.modals}
+        {!props.codeEditor && <>
+          <div className="maputnik-layout-list">
+            {props.layerList}
+          </div>
+          <div className="maputnik-layout-drawer">
+            <ScrollContainer>
+              {props.layerEditor}
+            </ScrollContainer>
+          </div>
+        </>}
+        {props.map}
       </div>
-    </IconContext.Provider>;
-  }
-}
+      {props.bottom && <div className="maputnik-layout-bottom">
+        {props.bottom}
+      </div>
+      }
+      {props.modals}
+    </div>
+  </IconContext.Provider>;
+};
 
 export const AppLayout = withTranslation()(AppLayoutInternal);

src/components/AppMessagePanel.tsx

@@ -13,52 +13,49 @@ type AppMessagePanelInternalProps = {
   selectedLayerIndex?: number
 } & WithTranslation;
 
-class AppMessagePanelInternal extends React.Component<AppMessagePanelInternalProps> {
-  static defaultProps = {
-    onLayerSelect: () => { },
-  };
+const AppMessagePanelInternal: React.FC<AppMessagePanelInternalProps> = ({
+  onLayerSelect = () => { },
+  ...props
+}) => {
+  const { t, selectedLayerIndex } = props;
+  const errors = props.errors?.map((error, idx) => {
+    let content;
+    if (error.parsed && error.parsed.type === "layer") {
+      const { parsed } = error;
+      const layerId = props.mapStyle?.layers[parsed.data.index].id;
+      content = (
+        <>
+          {t("Layer")} <span>{formatLayerId(layerId)}</span>: {parsed.data.message}
+          {selectedLayerIndex !== parsed.data.index &&
+            <>
+              &nbsp;&mdash;&nbsp;
+              <button
+                className="maputnik-message-panel__switch-button"
+                onClick={() => onLayerSelect!(parsed.data.index)}
+              >
+                {t("switch to layer")}
+              </button>
+            </>
+          }
+        </>
+      );
+    }
+    else {
+      content = error.message;
+    }
+    return <p key={"error-" + idx} className="maputnik-message-panel-error">
+      {content}
+    </p>;
+  });
 
-  render() {
-    const { t, selectedLayerIndex } = this.props;
-    const errors = this.props.errors?.map((error, idx) => {
-      let content;
-      if (error.parsed && error.parsed.type === "layer") {
-        const { parsed } = error;
-        const layerId = this.props.mapStyle?.layers[parsed.data.index].id;
-        content = (
-          <>
-            {t("Layer")} <span>{formatLayerId(layerId)}</span>: {parsed.data.message}
-            {selectedLayerIndex !== parsed.data.index &&
-              <>
-                &nbsp;&mdash;&nbsp;
-                <button
-                  className="maputnik-message-panel__switch-button"
-                  onClick={() => this.props.onLayerSelect!(parsed.data.index)}
-                >
-                  {t("switch to layer")}
-                </button>
-              </>
-            }
-          </>
-        );
-      }
-      else {
-        content = error.message;
-      }
-      return <p key={"error-" + idx} className="maputnik-message-panel-error">
-        {content}
-      </p>;
-    });
+  const infos = props.infos?.map((m, i) => {
+    return <p key={"info-" + i}>{m}</p>;
+  });
 
-    const infos = this.props.infos?.map((m, i) => {
-      return <p key={"info-" + i}>{m}</p>;
-    });
-
-    return <div className="maputnik-message-panel">
-      {errors}
-      {infos}
-    </div>;
-  }
-}
+  return <div className="maputnik-message-panel">
+    {errors}
+    {infos}
+  </div>;
+};
 
 export const AppMessagePanel = withTranslation()(AppMessagePanelInternal);

src/components/AppToolbar.tsx

@@ -31,11 +31,9 @@ type IconTextProps = {
 };
 
 
-class IconText extends React.Component<IconTextProps> {
-  render() {
-    return <span className="maputnik-icon-text">{this.props.children}</span>;
-  }
-}
+const IconText: React.FC<IconTextProps> = (props) => {
+  return <span className="maputnik-icon-text">{props.children}</span>;
+};
 
 type ToolbarLinkProps = {
   className?: string
@@ -43,35 +41,31 @@ type ToolbarLinkProps = {
   href?: string
 };
 
-class ToolbarLink extends React.Component<ToolbarLinkProps> {
-  render() {
-    return <a
-      className={classnames("maputnik-toolbar-link", this.props.className)}
-      href={this.props.href}
-      rel="noopener noreferrer"
-      target="_blank"
-      data-wd-key="toolbar:link"
-    >
-      {this.props.children}
-    </a>;
-  }
-}
+const ToolbarLink: React.FC<ToolbarLinkProps> = (props) => {
+  return <a
+    className={classnames("maputnik-toolbar-link", props.className)}
+    href={props.href}
+    rel="noopener noreferrer"
+    target="_blank"
+    data-wd-key="toolbar:link"
+  >
+    {props.children}
+  </a>;
+};
 
 type ToolbarSelectProps = {
   children?: React.ReactNode
   wdKey?: string
 };
 
-class ToolbarSelect extends React.Component<ToolbarSelectProps> {
-  render() {
-    return <div
-      className='maputnik-toolbar-select'
-      data-wd-key={this.props.wdKey}
-    >
-      {this.props.children}
-    </div>;
-  }
-}
+const ToolbarSelect: React.FC<ToolbarSelectProps> = (props) => {
+  return <div
+    className='maputnik-toolbar-select'
+    data-wd-key={props.wdKey}
+  >
+    {props.children}
+  </div>;
+};
 
 type ToolbarActionProps = {
   children?: React.ReactNode
@@ -79,17 +73,15 @@ type ToolbarActionProps = {
   wdKey?: string
 };
 
-class ToolbarAction extends React.Component<ToolbarActionProps> {
-  render() {
-    return <button
-      className='maputnik-toolbar-action'
-      data-wd-key={this.props.wdKey}
-      onClick={this.props.onClick}
-    >
-      {this.props.children}
-    </button>;
-  }
-}
+const ToolbarAction: React.FC<ToolbarActionProps> = (props) => {
+  return <button
+    className='maputnik-toolbar-action'
+    data-wd-key={props.wdKey}
+    onClick={props.onClick}
+  >
+    {props.children}
+  </button>;
+};
 
 export type MapState = "map" | "inspect" | "filter-achromatopsia" | "filter-deuteranopia" | "filter-protanopia" | "filter-tritanopia";
 
@@ -108,26 +100,16 @@ type AppToolbarInternalProps = {
   renderer?: string
 } & WithTranslation;
 
-class AppToolbarInternal extends React.Component<AppToolbarInternalProps> {
-  state = {
-    isOpen: {
-      settings: false,
-      sources: false,
-      open: false,
-      add: false,
-      export: false,
-    }
-  };
-
-  handleSelection(val: MapState) {
-    this.props.onSetMapState(val);
+const AppToolbarInternal: React.FC<AppToolbarInternalProps> = (props) => {
+  function handleSelection(val: MapState) {
+    props.onSetMapState(val);
   }
 
-  handleLanguageChange(val: string) {
-    this.props.i18n.changeLanguage(val);
+  function handleLanguageChange(val: string) {
+    props.i18n.changeLanguage(val);
   }
 
-  onSkip = (target: string) => {
+  const onSkip = (target: string) => {
     if (target === "map") {
       (document.querySelector(".maplibregl-canvas") as HTMLCanvasElement).focus();
     }
@@ -137,173 +119,171 @@ class AppToolbarInternal extends React.Component<AppToolbarInternalProps> {
     }
   };
 
-  render() {
-    const t = this.props.t;
-    const views = [
-      {
-        id: "map",
-        group: "general",
-        title: t("Map"),
-      },
-      {
-        id: "inspect",
-        group: "general",
-        title: t("Inspect"),
-        disabled: this.props.renderer === "ol",
-      },
-      {
-        id: "filter-deuteranopia",
-        group: "color-accessibility",
-        title: t("Deuteranopia filter"),
-        disabled: !colorAccessibilityFiltersEnabled,
-      },
-      {
-        id: "filter-protanopia",
-        group: "color-accessibility",
-        title: t("Protanopia filter"),
-        disabled: !colorAccessibilityFiltersEnabled,
-      },
-      {
-        id: "filter-tritanopia",
-        group: "color-accessibility",
-        title: t("Tritanopia filter"),
-        disabled: !colorAccessibilityFiltersEnabled,
-      },
-      {
-        id: "filter-achromatopsia",
-        group: "color-accessibility",
-        title: t("Achromatopsia filter"),
-        disabled: !colorAccessibilityFiltersEnabled,
-      },
-    ];
+  const t = props.t;
+  const views = [
+    {
+      id: "map",
+      group: "general",
+      title: t("Map"),
+    },
+    {
+      id: "inspect",
+      group: "general",
+      title: t("Inspect"),
+      disabled: props.renderer === "ol",
+    },
+    {
+      id: "filter-deuteranopia",
+      group: "color-accessibility",
+      title: t("Deuteranopia filter"),
+      disabled: !colorAccessibilityFiltersEnabled,
+    },
+    {
+      id: "filter-protanopia",
+      group: "color-accessibility",
+      title: t("Protanopia filter"),
+      disabled: !colorAccessibilityFiltersEnabled,
+    },
+    {
+      id: "filter-tritanopia",
+      group: "color-accessibility",
+      title: t("Tritanopia filter"),
+      disabled: !colorAccessibilityFiltersEnabled,
+    },
+    {
+      id: "filter-achromatopsia",
+      group: "color-accessibility",
+      title: t("Achromatopsia filter"),
+      disabled: !colorAccessibilityFiltersEnabled,
+    },
+  ];
 
-    const currentView = views.find((view) => {
-      return view.id === this.props.mapState;
-    });
+  const currentView = views.find((view) => {
+    return view.id === props.mapState;
+  });
 
-    return <nav className='maputnik-toolbar'>
-      <div className="maputnik-toolbar__inner">
-        <div
-          className="maputnik-toolbar-logo-container"
+  return <nav className='maputnik-toolbar'>
+    <div className="maputnik-toolbar__inner">
+      <div
+        className="maputnik-toolbar-logo-container"
+      >
+        {/* Keyboard accessible quick links */}
+        <button
+          data-wd-key="root:skip:layer-list"
+          className="maputnik-toolbar-skip"
+          onClick={_e => onSkip("layer-list")}
         >
-          {/* Keyboard accessible quick links */}
-          <button
-            data-wd-key="root:skip:layer-list"
-            className="maputnik-toolbar-skip"
-            onClick={_e => this.onSkip("layer-list")}
-          >
-            {t("Layers list")}
-          </button>
-          <button
-            data-wd-key="root:skip:layer-editor"
-            className="maputnik-toolbar-skip"
-            onClick={_e => this.onSkip("layer-editor")}
-          >
-            {t("Layer editor")}
-          </button>
-          <button
-            data-wd-key="root:skip:map-view"
-            className="maputnik-toolbar-skip"
-            onClick={_e => this.onSkip("map")}
-          >
-            {t("Map view")}
-          </button>
-          <a
-            className="maputnik-toolbar-logo"
-            target="blank"
-            rel="noreferrer noopener"
-            href="https://github.com/maplibre/maputnik"
-          >
-            <img src={maputnikLogo} alt={t("Maputnik on GitHub")} />
-            <h1>
-              <span className="maputnik-toolbar-name">{pkgJson.name}</span>
-              <span className="maputnik-toolbar-version">v{pkgJson.version}</span>
-            </h1>
-          </a>
-        </div>
-        <div className="maputnik-toolbar__actions" role="navigation" aria-label="Toolbar">
-          <ToolbarAction wdKey="nav:open" onClick={() => this.props.onToggleModal("open")}>
-            <MdOpenInBrowser />
-            <IconText>{t("Open")}</IconText>
-          </ToolbarAction>
-          <ToolbarAction wdKey="nav:export" onClick={() => this.props.onToggleModal("export")}>
-            <MdSave />
-            <IconText>{t("Save")}</IconText>
-          </ToolbarAction>
-          <ToolbarAction wdKey="nav:code-editor" onClick={() => this.props.onToggleModal("codeEditor")}>
-            <MdCode />
-            <IconText>{t("Code Editor")}</IconText>
-          </ToolbarAction>
-          <ToolbarAction wdKey="nav:sources" onClick={() => this.props.onToggleModal("sources")}>
-            <MdLayers />
-            <IconText>{t("Data Sources")}</IconText>
-          </ToolbarAction>
-          <ToolbarAction wdKey="nav:settings" onClick={() => this.props.onToggleModal("settings")}>
-            <MdSettings />
-            <IconText>{t("Style Settings")}</IconText>
-          </ToolbarAction>
-          <ToolbarAction wdKey="nav:global-state" onClick={() => this.props.onToggleModal("globalState")}>
-            <MdPublic />
-            <IconText>{t("Global State")}</IconText>
-          </ToolbarAction>
+          {t("Layers list")}
+        </button>
+        <button
+          data-wd-key="root:skip:layer-editor"
+          className="maputnik-toolbar-skip"
+          onClick={_e => onSkip("layer-editor")}
+        >
+          {t("Layer editor")}
+        </button>
+        <button
+          data-wd-key="root:skip:map-view"
+          className="maputnik-toolbar-skip"
+          onClick={_e => onSkip("map")}
+        >
+          {t("Map view")}
+        </button>
+        <a
+          className="maputnik-toolbar-logo"
+          target="blank"
+          rel="noreferrer noopener"
+          href="https://github.com/maplibre/maputnik"
+        >
+          <img src={maputnikLogo} alt={t("Maputnik on GitHub")} />
+          <h1>
+            <span className="maputnik-toolbar-name">{pkgJson.name}</span>
+            <span className="maputnik-toolbar-version">v{pkgJson.version}</span>
+          </h1>
+        </a>
+      </div>
+      <div className="maputnik-toolbar__actions" role="navigation" aria-label="Toolbar">
+        <ToolbarAction wdKey="nav:open" onClick={() => props.onToggleModal("open")}>
+          <MdOpenInBrowser />
+          <IconText>{t("Open")}</IconText>
+        </ToolbarAction>
+        <ToolbarAction wdKey="nav:export" onClick={() => props.onToggleModal("export")}>
+          <MdSave />
+          <IconText>{t("Save")}</IconText>
+        </ToolbarAction>
+        <ToolbarAction wdKey="nav:code-editor" onClick={() => props.onToggleModal("codeEditor")}>
+          <MdCode />
+          <IconText>{t("Code Editor")}</IconText>
+        </ToolbarAction>
+        <ToolbarAction wdKey="nav:sources" onClick={() => props.onToggleModal("sources")}>
+          <MdLayers />
+          <IconText>{t("Data Sources")}</IconText>
+        </ToolbarAction>
+        <ToolbarAction wdKey="nav:settings" onClick={() => props.onToggleModal("settings")}>
+          <MdSettings />
+          <IconText>{t("Style Settings")}</IconText>
+        </ToolbarAction>
+        <ToolbarAction wdKey="nav:global-state" onClick={() => props.onToggleModal("globalState")}>
+          <MdPublic />
+          <IconText>{t("Global State")}</IconText>
+        </ToolbarAction>
 
-          <ToolbarSelect wdKey="nav:inspect">
-            <MdFindInPage />
-            <IconText>{t("View")}
-              <select
-                className="maputnik-select"
-                data-wd-key="maputnik-select"
-                onChange={(e) => this.handleSelection(e.target.value as MapState)}
-                value={currentView?.id}
-              >
-                {views.filter(v => v.group === "general").map((item) => {
+        <ToolbarSelect wdKey="nav:inspect">
+          <MdFindInPage />
+          <IconText>{t("View")}
+            <select
+              className="maputnik-select"
+              data-wd-key="maputnik-select"
+              onChange={(e) => handleSelection(e.target.value as MapState)}
+              value={currentView?.id}
+            >
+              {views.filter(v => v.group === "general").map((item) => {
+                return (
+                  <option key={item.id} value={item.id} disabled={item.disabled} data-wd-key={item.id}>
+                    {item.title}
+                  </option>
+                );
+              })}
+              <optgroup label={t("Color accessibility")}>
+                {views.filter(v => v.group === "color-accessibility").map((item) => {
                   return (
-                    <option key={item.id} value={item.id} disabled={item.disabled} data-wd-key={item.id}>
+                    <option key={item.id} value={item.id} disabled={item.disabled}>
                       {item.title}
                     </option>
                   );
                 })}
-                <optgroup label={t("Color accessibility")}>
-                  {views.filter(v => v.group === "color-accessibility").map((item) => {
-                    return (
-                      <option key={item.id} value={item.id} disabled={item.disabled}>
-                        {item.title}
-                      </option>
-                    );
-                  })}
-                </optgroup>
-              </select>
-            </IconText>
-          </ToolbarSelect>
+              </optgroup>
+            </select>
+          </IconText>
+        </ToolbarSelect>
 
-          <ToolbarSelect wdKey="nav:language">
-            <MdLanguage />
-            <IconText>Language
-              <select
-                className="maputnik-select"
-                data-wd-key="maputnik-lang-select"
-                onChange={(e) => this.handleLanguageChange(e.target.value)}
-                value={this.props.i18n.language}
-              >
-                {Object.entries(supportedLanguages).map(([code, name]) => {
-                  return (
-                    <option key={code} value={code}>
-                      {name}
-                    </option>
-                  );
-                })}
-              </select>
-            </IconText>
-          </ToolbarSelect>
+        <ToolbarSelect wdKey="nav:language">
+          <MdLanguage />
+          <IconText>Language
+            <select
+              className="maputnik-select"
+              data-wd-key="maputnik-lang-select"
+              onChange={(e) => handleLanguageChange(e.target.value)}
+              value={props.i18n.language}
+            >
+              {Object.entries(supportedLanguages).map(([code, name]) => {
+                return (
+                  <option key={code} value={code}>
+                    {name}
+                  </option>
+                );
+              })}
+            </select>
+          </IconText>
+        </ToolbarSelect>
 
-          <ToolbarLink href={"https://github.com/maplibre/maputnik/wiki"}>
-            <MdHelpOutline />
-            <IconText>{t("Help")}</IconText>
-          </ToolbarLink>
-        </div>
+        <ToolbarLink href={"https://github.com/maplibre/maputnik/wiki"}>
+          <MdHelpOutline />
+          <IconText>{t("Help")}</IconText>
+        </ToolbarLink>
       </div>
-    </nav>;
-  }
-}
+    </div>
+  </nav>;
+};
 
 export const AppToolbar = withTranslation()(AppToolbarInternal);

src/components/Block.tsx

@@ -1,4 +1,4 @@
-import React, {type CSSProperties, type PropsWithChildren, type SyntheticEvent} from "react";
+import React, {type CSSProperties, type PropsWithChildren, type SyntheticEvent, useRef, useState} from "react";
 import classnames from "classnames";
 import { FieldDocLabel } from "./FieldDocLabel";
 import { Doc } from "./Doc";
@@ -14,32 +14,13 @@ export type BlockProps = PropsWithChildren & {
   error?: {message: string}
 };
 
-type BlockState = {
-  showDoc: boolean
-};
-
 /** Wrap a component with a label */
-export class Block extends React.Component<BlockProps, BlockState> {
-  _blockEl: HTMLDivElement | null = null;
+export const Block: React.FC<BlockProps> = (props) => {
+  const [showDoc, setShowDoc] = useState(false);
+  const blockEl = useRef<HTMLDivElement | null>(null);
 
-  constructor (props: BlockProps) {
-    super(props);
-    this.state = {
-      showDoc: false,
-    };
-  }
-
-  onChange(e: React.BaseSyntheticEvent<Event, HTMLInputElement, HTMLInputElement>) {
-    const value = e.target.value;
-    if (this.props.onChange) {
-      return this.props.onChange(value === "" ? undefined : value);
-    }
-  }
-
-  onToggleDoc = (val: boolean) => {
-    this.setState({
-      showDoc: val
-    });
+  const onToggleDoc = (val: boolean) => {
+    setShowDoc(val);
   };
 
   /**
@@ -48,9 +29,9 @@ export class Block extends React.Component<BlockProps, BlockState> {
    * causing the picker to reopen. This causes a scenario where the picker can
    * never be closed once open.
    */
-  onLabelClick = (event: SyntheticEvent<any, any>) => {
+  const onLabelClick = (event: SyntheticEvent<any, any>) => {
     const el = event.nativeEvent.target;
-    const contains = this._blockEl?.contains(el);
+    const contains = blockEl.current?.contains(el);
 
     if (event.nativeEvent.target.nodeName !== "INPUT" && !contains) {
       event.stopPropagation();
@@ -60,45 +41,43 @@ export class Block extends React.Component<BlockProps, BlockState> {
     }
   };
 
-  render() {
-    return <label style={this.props.style}
-      data-wd-key={this.props["data-wd-key"]}
-      className={classnames({
-        "maputnik-input-block": true,
-        "maputnik-input-block--wide": this.props.wideMode,
-        "maputnik-action-block": this.props.action,
-        "maputnik-input-block--error": this.props.error
-      })}
-      onClick={this.onLabelClick}
-    >
-      {this.props.fieldSpec &&
-        <div className="maputnik-input-block-label">
-          <FieldDocLabel
-            label={this.props.label}
-            onToggleDoc={this.onToggleDoc}
-            fieldSpec={this.props.fieldSpec}
-          />
-        </div>
-      }
-      {!this.props.fieldSpec &&
-        <div className="maputnik-input-block-label">
-          {this.props.label}
-        </div>
-      }
-      <div className="maputnik-input-block-action">
-        {this.props.action}
+  return <label style={props.style}
+    data-wd-key={props["data-wd-key"]}
+    className={classnames({
+      "maputnik-input-block": true,
+      "maputnik-input-block--wide": props.wideMode,
+      "maputnik-action-block": props.action,
+      "maputnik-input-block--error": props.error
+    })}
+    onClick={onLabelClick}
+  >
+    {props.fieldSpec &&
+      <div className="maputnik-input-block-label">
+        <FieldDocLabel
+          label={props.label}
+          onToggleDoc={onToggleDoc}
+          fieldSpec={props.fieldSpec}
+        />
       </div>
-      <div className="maputnik-input-block-content" ref={el => {this._blockEl = el;}}>
-        {this.props.children}
+    }
+    {!props.fieldSpec &&
+      <div className="maputnik-input-block-label">
+        {props.label}
       </div>
-      {this.props.fieldSpec &&
-        <div
-          className="maputnik-doc-inline"
-          style={{display: this.state.showDoc ? "" : "none"}}
-        >
-          <Doc fieldSpec={this.props.fieldSpec} />
-        </div>
-      }
-    </label>;
-  }
-}
+    }
+    <div className="maputnik-input-block-action">
+      {props.action}
+    </div>
+    <div className="maputnik-input-block-content" ref={blockEl}>
+      {props.children}
+    </div>
+    {props.fieldSpec &&
+      <div
+        className="maputnik-doc-inline"
+        style={{display: showDoc ? "" : "none"}}
+      >
+        <Doc fieldSpec={props.fieldSpec} />
+      </div>
+    }
+  </label>;
+};

src/components/Collapse.tsx

@@ -9,25 +9,19 @@ type CollapseProps = {
 };
 
 
-export class Collapse extends React.Component<CollapseProps> {
-  static defaultProps = {
-    isActive: true
-  };
-
-  render() {
-    if (reducedMotionEnabled()) {
-      return (
-        <div style={{display: this.props.isActive ? "block" : "none"}}>
-          {this.props.children}
-        </div>
-      );
-    }
-    else {
-      return (
-        <ReactCollapse isOpened={this.props.isActive}>
-          {this.props.children}
-        </ReactCollapse>
-      );
-    }
+export const Collapse: React.FC<CollapseProps> = ({isActive = true, children}) => {
+  if (reducedMotionEnabled()) {
+    return (
+      <div style={{display: isActive ? "block" : "none"}}>
+        {children}
+      </div>
+    );
   }
-}
+  else {
+    return (
+      <ReactCollapse isOpened={isActive}>
+        {children}
+      </ReactCollapse>
+    );
+  }
+};

src/components/Collapser.tsx

@@ -6,13 +6,11 @@ type CollapserProps = {
   style?: object
 };
 
-export class Collapser extends React.Component<CollapserProps> {
-  render() {
-    const iconStyle = {
-      width: 20,
-      height: 20,
-      ...this.props.style,
-    };
-    return this.props.isCollapsed ? <MdArrowDropUp style={iconStyle}/> : <MdArrowDropDown style={iconStyle} />;
-  }
-}
+export const Collapser: React.FC<CollapserProps> = (props) => {
+  const iconStyle = {
+    width: 20,
+    height: 20,
+    ...props.style,
+  };
+  return props.isCollapsed ? <MdArrowDropUp style={iconStyle}/> : <MdArrowDropDown style={iconStyle} />;
+};

src/components/DataProperty.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useRef } from "react";
 import {PiListPlusBold} from "react-icons/pi";
 import {TbMathFunction} from "react-icons/tb";
 import latest from "@maplibre/maplibre-gl-style-spec/dist/latest.json";
@@ -68,32 +68,19 @@ export type Stop = [{
   value: number
 }, number];
 
-class DataPropertyInternal extends React.Component<DataPropertyInternalProps, DataPropertyState> {
-  state = {
-    refs: {} as {[key: number]: string}
-  };
-
-  componentDidMount() {
-    const newRefs = setStopRefs(this.props, this.state);
-
-    if(newRefs) {
-      this.setState({
-        refs: newRefs
-      });
-    }
+const DataPropertyInternal: React.FC<DataPropertyInternalProps> = (props) => {
+  // Kept in a ref rather than state: the original recomputed these on every
+  // render via getDerivedStateFromProps, which as state would mean setting
+  // state during render on every pass.
+  const refs = useRef<{[key: number]: string}>({});
+  // setStopRefs returns undefined when no new stop needs a ref; as in the
+  // original, only replace the map when it actually produced one.
+  const newStopRefs = setStopRefs(props, { refs: refs.current });
+  if (newStopRefs) {
+    refs.current = newStopRefs;
   }
 
-  static getDerivedStateFromProps(props: Readonly<DataPropertyInternalProps>, state: DataPropertyState) {
-    const newRefs = setStopRefs(props, state);
-    if(newRefs) {
-      return {
-        refs: newRefs
-      };
-    }
-    return null;
-  }
-
-  getFieldFunctionType(fieldSpec: any) {
+  function getFieldFunctionType(fieldSpec: any) {
     if (fieldSpec.expression.interpolated) {
       return "exponential";
     }
@@ -103,7 +90,7 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
     return "categorical";
   }
 
-  getDataFunctionTypes(fieldSpec: any) {
+  function getDataFunctionTypes(fieldSpec: any) {
     if (fieldSpec.expression.interpolated) {
       return ["interpolate", "categorical", "interval", "exponential", "identity"];
     }
@@ -113,11 +100,11 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
   }
 
   // Order the stops altering the refs to reflect their new position.
-  orderStopsByZoom(stops: Stop[]) {
+  function orderStopsByZoom(stops: Stop[]) {
     const mappedWithRef = stops
       .map((stop, idx) => {
         return {
-          ref: this.state.refs[idx],
+          ref: refs.current[idx],
           data: stop
         };
       })
@@ -131,14 +118,12 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
         newRefs[idx] = stop.ref;
       });
 
-    this.setState({
-      refs: newRefs
-    });
+    refs.current = newRefs;
 
     return mappedWithRef.map((item) => item.data);
   }
 
-  onChange = (fieldName: string, value: any) => {
+  const onChange = (fieldName: string, value: any) => {
     if (value.type === "identity") {
       value = {
         type: value.type,
@@ -152,17 +137,17 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
         type: value.type,
         // Default props if they don't already exist.
         stops: [
-          [{zoom: 6, value: stopValue}, findDefaultFromSpec(this.props.fieldSpec as any)],
-          [{zoom: 10, value: stopValue}, findDefaultFromSpec(this.props.fieldSpec as any)]
+          [{zoom: 6, value: stopValue}, findDefaultFromSpec(props.fieldSpec as any)],
+          [{zoom: 10, value: stopValue}, findDefaultFromSpec(props.fieldSpec as any)]
         ],
         ...value,
       };
     }
-    this.props.onChange!(fieldName, value);
+    props.onChange!(fieldName, value);
   };
 
-  changeStop(changeIdx: number, stopData: { zoom: number | undefined, value: number }, value: number) {
-    const stops = this.props.value?.stops.slice(0) || [];
+  function changeStop(changeIdx: number, stopData: { zoom: number | undefined, value: number }, value: number) {
+    const stops = props.value?.stops.slice(0) || [];
     // const changedStop = stopData.zoom === undefined ? stopData.value : stopData
     stops[changeIdx] = [
       {
@@ -172,135 +157,134 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
       value
     ];
 
-    const orderedStops = this.orderStopsByZoom(stops);
+    const orderedStops = orderStopsByZoom(stops);
 
     const changedValue = {
-      ...this.props.value,
+      ...props.value,
       stops: orderedStops,
     };
-    this.onChange(this.props.fieldName, changedValue);
+    onChange(props.fieldName, changedValue);
   }
 
-  changeBase(newValue: number | undefined) {
+  function changeBase(newValue: number | undefined) {
     const changedValue = {
-      ...this.props.value,
+      ...props.value,
       base: newValue
     };
 
     if (changedValue.base === undefined) {
       delete changedValue["base"];
     }
-    this.props.onChange!(this.props.fieldName, changedValue);
+    props.onChange!(props.fieldName, changedValue);
   }
 
-  changeDataType(propVal: string) {
-    if (propVal === "interpolate" && this.props.onChangeToZoomFunction) {
-      this.props.onChangeToZoomFunction();
+  function changeDataType(propVal: string) {
+    if (propVal === "interpolate" && props.onChangeToZoomFunction) {
+      props.onChangeToZoomFunction();
     }
     else {
-      this.onChange(this.props.fieldName, {
-        ...this.props.value,
+      onChange(props.fieldName, {
+        ...props.value,
         type: propVal,
       });
     }
   }
 
-  changeDataProperty(propName: "property" | "default", propVal: any) {
+  function changeDataProperty(propName: "property" | "default", propVal: any) {
     if (propVal) {
-      this.props.value![propName] = propVal;
+      props.value![propName] = propVal;
     }
     else {
-      delete this.props.value![propName];
+      delete props.value![propName];
     }
-    this.onChange(this.props.fieldName, this.props.value);
+    onChange(props.fieldName, props.value);
   }
 
-  render() {
-    const t = this.props.t;
+  const t = props.t;
 
-    if (typeof this.props.value?.type === "undefined") {
-      this.props.value!.type = this.getFieldFunctionType(this.props.fieldSpec);
-    }
+  if (typeof props.value?.type === "undefined") {
+    props.value!.type = getFieldFunctionType(props.fieldSpec);
+  }
 
-    let dataFields;
-    if (this.props.value?.stops) {
-      dataFields = this.props.value.stops.map((stop, idx) => {
-        const zoomLevel = typeof stop[0] === "object" ? stop[0].zoom : undefined;
-        const key  = this.state.refs[idx];
-        const dataLevel = typeof stop[0] === "object" ? stop[0].value : stop[0];
-        const value = stop[1];
-        const deleteStopBtn = <DeleteStopButton onClick={this.props.onDeleteStop?.bind(this, idx)} />;
+  let dataFields;
+  if (props.value?.stops) {
+    dataFields = props.value.stops.map((stop, idx) => {
+      const zoomLevel = typeof stop[0] === "object" ? stop[0].zoom : undefined;
+      const key  = refs.current[idx];
+      const dataLevel = typeof stop[0] === "object" ? stop[0].value : stop[0];
+      const value = stop[1];
+      const deleteStopBtn = <DeleteStopButton onClick={props.onDeleteStop?.bind(null, idx)} />;
 
-        const dataProps = {
-          "aria-label": t("Input value"),
-          label: t("Data value"),
-          value: dataLevel as any,
-          onChange: (newData: string | number | undefined) => this.changeStop(idx, { zoom: zoomLevel, value: newData as number }, value)
-        };
+      const dataProps = {
+        "aria-label": t("Input value"),
+        label: t("Data value"),
+        value: dataLevel as any,
+        onChange: (newData: string | number | undefined) => changeStop(idx, { zoom: zoomLevel, value: newData as number }, value)
+      };
 
-        let dataInput;
-        if(this.props.value?.type === "categorical") {
-          dataInput = <InputString {...dataProps} />;
-        }
-        else {
-          dataInput = <InputNumber {...dataProps} />;
-        }
+      let dataInput;
+      if(props.value?.type === "categorical") {
+        dataInput = <InputString {...dataProps} />;
+      }
+      else {
+        dataInput = <InputNumber {...dataProps} />;
+      }
 
-        let zoomInput = null;
-        if(zoomLevel !== undefined) {
-          zoomInput = <div>
-            <InputNumber
-              aria-label="Zoom"
-              value={zoomLevel}
-              onChange={newZoom => this.changeStop(idx, {zoom: newZoom, value: dataLevel}, value)}
-              min={0}
-              max={22}
+      let zoomInput = null;
+      if(zoomLevel !== undefined) {
+        zoomInput = <div>
+          <InputNumber
+            aria-label="Zoom"
+            value={zoomLevel}
+            onChange={newZoom => changeStop(idx, {zoom: newZoom, value: dataLevel}, value)}
+            min={0}
+            max={22}
+          />
+        </div>;
+      }
+
+      return <tr key={key}>
+        <td>
+          {zoomInput}
+        </td>
+        <td>
+          {dataInput}
+        </td>
+        <td>
+          <InputSpec
+            aria-label={t("Output value")}
+            fieldName={props.fieldName}
+            fieldSpec={props.fieldSpec}
+            value={value}
+            onChange={(_, newValue) => changeStop(idx, {zoom: zoomLevel, value: dataLevel}, newValue as number)}
+          />
+        </td>
+        <td>
+          {deleteStopBtn}
+        </td>
+      </tr>;
+    });
+  }
+
+  return <div className="maputnik-data-spec-block">
+    <fieldset className="maputnik-data-spec-property">
+      <legend>{labelFromFieldName(props.fieldName)}</legend>
+      <div className="maputnik-data-fieldset-inner">
+        <Block
+          label={t("Function")}
+          key="function"
+          data-wd-key="function-type"
+        >
+          <div className="maputnik-data-spec-property-input">
+            <InputSelect
+              value={props.value!.type}
+              onChange={(propVal: string) => changeDataType(propVal)}
+              title={t("Select a type of data scale (default is 'categorical').")}
+              options={getDataFunctionTypes(props.fieldSpec)}
             />
-          </div>;
-        }
-
-        return <tr key={key}>
-          <td>
-            {zoomInput}
-          </td>
-          <td>
-            {dataInput}
-          </td>
-          <td>
-            <InputSpec
-              aria-label={t("Output value")}
-              fieldName={this.props.fieldName}
-              fieldSpec={this.props.fieldSpec}
-              value={value}
-              onChange={(_, newValue) => this.changeStop(idx, {zoom: zoomLevel, value: dataLevel}, newValue as number)}
-            />
-          </td>
-          <td>
-            {deleteStopBtn}
-          </td>
-        </tr>;
-      });
-    }
-
-    return <div className="maputnik-data-spec-block">
-      <fieldset className="maputnik-data-spec-property">
-        <legend>{labelFromFieldName(this.props.fieldName)}</legend>
-        <div className="maputnik-data-fieldset-inner">
-          <Block
-            label={t("Function")}
-            key="function"
-            data-wd-key="function-type"
-          >
-            <div className="maputnik-data-spec-property-input">
-              <InputSelect
-                value={this.props.value!.type}
-                onChange={(propVal: string) => this.changeDataType(propVal)}
-                title={t("Select a type of data scale (default is 'categorical').")}
-                options={this.getDataFunctionTypes(this.props.fieldSpec)}
-              />
-            </div>
-          </Block>
-          {this.props.value?.type !== "identity" &&
+          </div>
+        </Block>
+        {props.value?.type !== "identity" &&
             <Block
               label={t("Base")}
               key="base"
@@ -310,40 +294,40 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
                 <InputSpec
                   fieldName={"base"}
                   fieldSpec={latest.function.base as typeof latest.function.base & { type: "number" }}
-                  value={this.props.value?.base}
-                  onChange={(_, newValue) => this.changeBase(newValue as number)}
+                  value={props.value?.base}
+                  onChange={(_, newValue) => changeBase(newValue as number)}
                 />
               </div>
             </Block>
-          }
-          <Block
-            label={"Property"}
-            key="property"
-            data-wd-key="function-property"
-          >
-            <div className="maputnik-data-spec-property-input">
-              <InputString
-                value={this.props.value?.property}
-                title={t("Input a data property to base styles off of.")}
-                onChange={propVal => this.changeDataProperty("property", propVal)}
-              />
-            </div>
-          </Block>
-          {dataFields &&
+        }
+        <Block
+          label={"Property"}
+          key="property"
+          data-wd-key="function-property"
+        >
+          <div className="maputnik-data-spec-property-input">
+            <InputString
+              value={props.value?.property}
+              title={t("Input a data property to base styles off of.")}
+              onChange={propVal => changeDataProperty("property", propVal)}
+            />
+          </div>
+        </Block>
+        {dataFields &&
             <Block
               label={t("Default")}
               key="default"
               data-wd-key="function-default"
             >
               <InputSpec
-                fieldName={this.props.fieldName}
-                fieldSpec={this.props.fieldSpec}
-                value={this.props.value?.default}
-                onChange={(_, propVal) => this.changeDataProperty("default", propVal)}
+                fieldName={props.fieldName}
+                fieldSpec={props.fieldSpec}
+                value={props.value?.default}
+                onChange={(_, propVal) => changeDataProperty("default", propVal)}
               />
             </Block>
-          }
-          {dataFields &&
+        }
+        {dataFields &&
             <div className="maputnik-function-stop">
               <table className="maputnik-function-stop-table">
                 <caption>{t("Stops")}</caption>
@@ -359,30 +343,29 @@ class DataPropertyInternal extends React.Component<DataPropertyInternalProps, Da
                 </tbody>
               </table>
             </div>
-          }
-          <div className="maputnik-toolbox">
-            {dataFields &&
+        }
+        <div className="maputnik-toolbox">
+          {dataFields &&
               <InputButton
                 className="maputnik-add-stop"
-                onClick={this.props.onAddStop?.bind(this)}
+                onClick={props.onAddStop?.bind(null)}
               >
                 <PiListPlusBold style={{ verticalAlign: "text-bottom" }} />
                 {t("Add stop")}
               </InputButton>
-            }
-            <InputButton
-              className="maputnik-add-stop"
-              data-wd-key="convert-to-expression"
-              onClick={this.props.onExpressionClick?.bind(this)}
-            >
-              <TbMathFunction style={{ verticalAlign: "text-bottom" }} />
-              {t("Convert to expression")}
-            </InputButton>
-          </div>
+          }
+          <InputButton
+            className="maputnik-add-stop"
+            data-wd-key="convert-to-expression"
+            onClick={props.onExpressionClick?.bind(null)}
+          >
+            <TbMathFunction style={{ verticalAlign: "text-bottom" }} />
+            {t("Convert to expression")}
+          </InputButton>
         </div>
-      </fieldset>
-    </div>;
-  }
-}
+      </div>
+    </fieldset>
+  </div>;
+};
 
 export const DataProperty = withTranslation()(DataPropertyInternal);

src/components/DeleteStopButton.tsx

@@ -10,17 +10,15 @@ type DeleteStopButtonInternalProps = {
 } & WithTranslation;
 
 
-class DeleteStopButtonInternal extends React.Component<DeleteStopButtonInternalProps> {
-  render() {
-    const t = this.props.t;
-    return <InputButton
-      className="maputnik-delete-stop"
-      onClick={this.props.onClick}
-      title={t("Remove zoom level from stop")}
-    >
-      <MdDelete />
-    </InputButton>;
-  }
-}
+const DeleteStopButtonInternal: React.FC<DeleteStopButtonInternalProps> = (props) => {
+  const t = props.t;
+  return <InputButton
+    className="maputnik-delete-stop"
+    onClick={props.onClick}
+    title={t("Remove zoom level from stop")}
+  >
+    <MdDelete />
+  </InputButton>;
+};
 
 export const DeleteStopButton = withTranslation()(DeleteStopButtonInternal);

src/components/Doc.tsx

@@ -23,88 +23,84 @@ type DocProps = {
   }
 };
 
-export class Doc extends React.Component<DocProps> {
-  render () {
-    const {fieldSpec} = this.props;
+export const Doc: React.FC<DocProps> = ({fieldSpec}) => {
+  const {doc, values, docUrl, docUrlLinkText} = fieldSpec;
+  const sdkSupport = fieldSpec["sdk-support"];
 
-    const {doc, values, docUrl, docUrlLinkText} = fieldSpec;
-    const sdkSupport = fieldSpec["sdk-support"];
+  const renderValues = (
+    !!values &&
+    // HACK: Currently we merge additional values into the style spec, so this is required
+    // See <https://github.com/maplibre/maputnik/blob/main/src/components/PropertyGroup.jsx#L16>
+    !Array.isArray(values)
+  );
 
-    const renderValues = (
-      !!values &&
-      // HACK: Currently we merge additional values into the style spec, so this is required
-      // See <https://github.com/maplibre/maputnik/blob/main/src/components/PropertyGroup.jsx#L16>
-      !Array.isArray(values)
-    );
+  const sdkSupportToJsx = (value: string) => {
+    const supportValue = value.toLowerCase();
+    if (supportValue.startsWith("https://")) {
+      return <a href={supportValue} target="_blank" rel="noreferrer">{"#" + supportValue.split("/").pop()}</a>;
+    }
+    return value;
+  };
 
-    const sdkSupportToJsx = (value: string) => {
-      const supportValue = value.toLowerCase();
-      if (supportValue.startsWith("https://")) {
-        return <a href={supportValue} target="_blank" rel="noreferrer">{"#" + supportValue.split("/").pop()}</a>;
+  return (
+    <>
+      {doc &&
+        <div className="SpecDoc">
+          <div className="SpecDoc__doc" data-wd-key='spec-field-doc'>
+            <Markdown components={{
+              a: ({node: _node, href, children, ...props}) => <a href={href} target="_blank" {...props}>{children}</a>,
+            }}>{doc}</Markdown>
+          </div>
+          {renderValues &&
+            <ul className="SpecDoc__values">
+              {Object.entries(values).map(([key, value]) => {
+                return (
+                  <li key={key}>
+                    <code>{JSON.stringify(key)}</code>
+                    <div>{value.doc}</div>
+                  </li>
+                );
+              })}
+            </ul>
+          }
+        </div>
       }
-      return value;
-    };
-
-    return (
-      <>
-        {doc &&
-          <div className="SpecDoc">
-            <div className="SpecDoc__doc" data-wd-key='spec-field-doc'>
-              <Markdown components={{
-                a: ({node: _node, href, children, ...props}) => <a href={href} target="_blank" {...props}>{children}</a>,
-              }}>{doc}</Markdown>
-            </div>
-            {renderValues &&
-              <ul className="SpecDoc__values">
-                {Object.entries(values).map(([key, value]) => {
-                  return (
-                    <li key={key}>
-                      <code>{JSON.stringify(key)}</code>
-                      <div>{value.doc}</div>
-                    </li>
-                  );
+      {sdkSupport &&
+        <div className="SpecDoc__sdk-support">
+          <table className="SpecDoc__sdk-support__table">
+            <thead>
+              <tr>
+                <th></th>
+                {Object.values(headers).map(header => {
+                  return <th key={header}>{header}</th>;
                 })}
-              </ul>
-            }
-          </div>
-        }
-        {sdkSupport &&
-          <div className="SpecDoc__sdk-support">
-            <table className="SpecDoc__sdk-support__table">
-              <thead>
-                <tr>
-                  <th></th>
-                  {Object.values(headers).map(header => {
-                    return <th key={header}>{header}</th>;
-                  })}
-                </tr>
-              </thead>
-              <tbody>
-                {Object.entries(sdkSupport).map(([key, supportObj]) => {
-                  return (
-                    <tr key={key}>
-                      <td>{key}</td>
-                      {Object.keys(headers).map((k) => {
-                        if (Object.prototype.hasOwnProperty.call(supportObj, k)) {
-                          return <td key={k}>{sdkSupportToJsx(supportObj[k as keyof typeof headers])}</td>;
-                        }
-                        else {
-                          return <td key={k}>no</td>;
-                        }
-                      })}
-                    </tr>
-                  );
-                })}
-              </tbody>
-            </table>
-          </div>
-        }
-        {docUrl && docUrlLinkText &&
-          <div className="SpecDoc__learn-more">
-            <a href={docUrl}  target="_blank" rel="noreferrer">{docUrlLinkText}</a>
-          </div>
-        }
-      </>
-    );
-  }
-}
+              </tr>
+            </thead>
+            <tbody>
+              {Object.entries(sdkSupport).map(([key, supportObj]) => {
+                return (
+                  <tr key={key}>
+                    <td>{key}</td>
+                    {Object.keys(headers).map((k) => {
+                      if (Object.prototype.hasOwnProperty.call(supportObj, k)) {
+                        return <td key={k}>{sdkSupportToJsx(supportObj[k as keyof typeof headers])}</td>;
+                      }
+                      else {
+                        return <td key={k}>no</td>;
+                      }
+                    })}
+                  </tr>
+                );
+              })}
+            </tbody>
+          </table>
+        </div>
+      }
+      {docUrl && docUrlLinkText &&
+        <div className="SpecDoc__learn-more">
+          <a href={docUrl}  target="_blank" rel="noreferrer">{docUrlLinkText}</a>
+        </div>
+      }
+    </>
+  );
+};

src/components/ExpressionProperty.tsx

@@ -24,72 +24,62 @@ type ExpressionPropertyInternalProps = {
   onBlur?(...args: unknown[]): unknown
 } & WithTranslation;
 
-class ExpressionPropertyInternal extends React.Component<ExpressionPropertyInternalProps> {
-  static defaultProps = {
-    errors: {},
-    onFocus: () => {},
-    onBlur: () => {},
-  };
+const ExpressionPropertyInternal: React.FC<ExpressionPropertyInternalProps> = ({
+  errors = {},
+  onFocus = () => {},
+  onBlur = () => {},
+  ...props
+}) => {
+  const {t, value, canUndo} = props;
+  const undoDisabled = canUndo ? !canUndo() : true;
 
-  constructor(props: ExpressionPropertyInternalProps) {
-    super(props);
-    this.state = {
-      jsonError: false,
-    };
-  }
-
-  render() {
-    const {t, value, canUndo} = this.props;
-    const undoDisabled = canUndo ? !canUndo() : true;
-
-    const deleteStopBtn = (
-      <>
-        {this.props.onUndo &&
-          <InputButton
-            key="undo_action"
-            onClick={this.props.onUndo}
-            disabled={undoDisabled}
-            className="maputnik-delete-stop"
-            data-wd-key="undo-expression"
-            title={t("Revert from expression")}
-          >
-            <MdUndo />
-          </InputButton>
-        }
+  const deleteStopBtn = (
+    <>
+      {props.onUndo &&
         <InputButton
-          key="delete_action"
-          onClick={this.props.onDelete}
+          key="undo_action"
+          onClick={props.onUndo}
+          disabled={undoDisabled}
           className="maputnik-delete-stop"
-          data-wd-key="delete-expression"
-          title={t("Delete expression")}
+          data-wd-key="undo-expression"
+          title={t("Revert from expression")}
         >
-          <MdDelete />
+          <MdUndo />
         </InputButton>
-      </>
-    );
-    let error = undefined;
-    if (this.props.errors) {
-      const fieldKey = this.props.fieldType ? this.props.fieldType + "." + this.props.fieldName : this.props.fieldName;
-      error = this.props.errors[fieldKey];
-    }
-    return <Block
-      fieldSpec={this.props.fieldSpec}
-      label={t(labelFromFieldName(this.props.fieldName))}
-      action={deleteStopBtn}
-      wideMode={true}
-      error={error}
-    >
-      <FieldJson
-        lintType="expression"
-        spec={this.props.fieldSpec}
-        className="maputnik-expression-editor"
-        onFocus={this.props.onFocus}
-        onBlur={this.props.onBlur}
-        value={value}
-        onChange={this.props.onChange}
-      />
-    </Block>;
+      }
+      <InputButton
+        key="delete_action"
+        onClick={props.onDelete}
+        className="maputnik-delete-stop"
+        data-wd-key="delete-expression"
+        title={t("Delete expression")}
+      >
+        <MdDelete />
+      </InputButton>
+    </>
+  );
+  let error = undefined;
+  if (errors) {
+    const fieldKey = props.fieldType ? props.fieldType + "." + props.fieldName : props.fieldName;
+    error = errors[fieldKey];
   }
-}
+  return <Block
+    fieldSpec={props.fieldSpec}
+    label={t(labelFromFieldName(props.fieldName))}
+    action={deleteStopBtn}
+    wideMode={true}
+    error={error}
+  >
+    <FieldJson
+      lintType="expression"
+      spec={props.fieldSpec}
+      className="maputnik-expression-editor"
+      onFocus={onFocus}
+      onBlur={onBlur}
+      value={value}
+      onChange={props.onChange}
+    />
+  </Block>;
+};
 
 export const ExpressionProperty = withTranslation()(ExpressionPropertyInternal);

src/components/FilterEditor.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useState } from "react";
 import { TbMathFunction } from "react-icons/tb";
 import { PiListPlusBold } from "react-icons/pi";
 import {isEqual} from "lodash";
@@ -100,222 +100,190 @@ type FilterEditorInternalProps = {
   onChange(value: LegacyFilterSpecification | ExpressionSpecification): void
 } & WithTranslation;
 
-type FilterEditorState = {
-  showDoc: boolean
-  displaySimpleFilter: boolean
-  valueIsSimpleFilter?: boolean
-};
+const FilterEditorInternal: React.FC<FilterEditorInternalProps> = ({ filter = ["all"], ...rest }) => {
+  const props = { filter, ...rest } as FilterEditorInternalProps;
 
-class FilterEditorInternal extends React.Component<FilterEditorInternalProps, FilterEditorState> {
-  static defaultProps = {
-    filter: ["all"],
-  };
+  // Nothing ever toggles this: the Block below renders its own documentation
+  // toggle, so this component's inline doc panel stays hidden (as it did before).
+  const [showDoc] = useState(false);
+  const [displaySimpleFilter, setDisplaySimpleFilter] = useState(() =>
+    checkIfSimpleFilter(combiningFilter(props))
+  );
 
-  constructor (props: FilterEditorInternalProps) {
-    super(props);
-    this.state = {
-      showDoc: false,
-      displaySimpleFilter: checkIfSimpleFilter(combiningFilter(props)),
-    };
+  // Replaces getDerivedStateFromProps. "Upgrade but never downgrade": once the
+  // filter stops being expressible in the simple editor, switch to the
+  // expression editor and stay there.
+  const isSimpleFilter = checkIfSimpleFilter(combiningFilter(props));
+  if (!isSimpleFilter && displaySimpleFilter) {
+    setDisplaySimpleFilter(false);
   }
+  // In the original this was state, but every branch derived it from these two
+  // values alone.
+  const valueIsSimpleFilter = isSimpleFilter && !displaySimpleFilter;
 
   // Convert filter to combining filter
-  onFilterPartChanged(filterIdx: number, newPart: any[]) {
-    const newFilter = combiningFilter(this.props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
+  function onFilterPartChanged(filterIdx: number, newPart: any[]) {
+    const newFilter = combiningFilter(props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
     newFilter[filterIdx] = newPart;
-    this.props.onChange(newFilter);
+    props.onChange(newFilter);
   }
 
-  deleteFilterItem(filterIdx: number) {
-    const newFilter = combiningFilter(this.props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
+  function deleteFilterItem(filterIdx: number) {
+    const newFilter = combiningFilter(props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
     newFilter.splice(filterIdx + 1, 1);
-    this.props.onChange(newFilter);
+    props.onChange(newFilter);
   }
 
-  addFilterItem = () => {
-    const newFilterItem = combiningFilter(this.props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
+  const addFilterItem = () => {
+    const newFilterItem = combiningFilter(props).slice(0) as LegacyFilterSpecification | ExpressionSpecification;
     (newFilterItem as any[]).push(["==", "name", ""]);
-    this.props.onChange(newFilterItem);
+    props.onChange(newFilterItem);
   };
 
-  onToggleDoc = (val: boolean) => {
-    this.setState({
-      showDoc: val
-    });
+  const makeFilter = () => {
+    setDisplaySimpleFilter(true);
   };
 
-  makeFilter = () => {
-    this.setState({
-      displaySimpleFilter: true,
-    });
+  const makeExpression = () => {
+    const currentFilter = combiningFilter(props);
+    props.onChange(migrateFilter(currentFilter));
+    setDisplaySimpleFilter(false);
   };
 
-  makeExpression = () => {
-    const filter = combiningFilter(this.props);
-    this.props.onChange(migrateFilter(filter));
-    this.setState({
-      displaySimpleFilter: false,
-    });
+
+  const {errors, t} = props;
+  const fieldSpec={
+    doc: latest.layer.filter.doc + " Combine multiple filters together by using a compound filter."
   };
+  const defaultFilter = ["all"] as LegacyFilterSpecification | ExpressionSpecification;
 
-  static getDerivedStateFromProps(props: Readonly<FilterEditorInternalProps>, state: FilterEditorState) {
-    const displaySimpleFilter = checkIfSimpleFilter(combiningFilter(props));
+  const isNestedCombiningFilter = displaySimpleFilter && hasNestedCombiningFilter(combiningFilter(props));
 
-    // Upgrade but never downgrade
-    if (!displaySimpleFilter && state.displaySimpleFilter === true) {
-      return {
-        displaySimpleFilter: false,
-        valueIsSimpleFilter: false,
-      };
-    }
-    else if (displaySimpleFilter && state.displaySimpleFilter === false) {
-      return {
-        valueIsSimpleFilter: true,
-      };
-    }
-    else {
-      return {
-        valueIsSimpleFilter: false,
-      };
-    }
+  if (isNestedCombiningFilter) {
+    return <div className="maputnik-filter-editor-unsupported">
+      <p>
+        {t("Nested filters are not supported.")}
+      </p>
+      <InputButton
+        onClick={makeExpression}
+        title={t("Convert to expression")}
+      >
+        <TbMathFunction />
+        {t("Upgrade to expression")}
+      </InputButton>
+    </div>;
   }
+  else if (displaySimpleFilter) {
+    const filter = combiningFilter(props);
+    const combiningOp = filter[0];
+    const filters = filter.slice(1) as (LegacyFilterSpecification | ExpressionSpecification)[];
 
-  render() {
-    const {errors, t} = this.props;
-    const {displaySimpleFilter} = this.state;
-    const fieldSpec={
-      doc: latest.layer.filter.doc + " Combine multiple filters together by using a compound filter."
-    };
-    const defaultFilter = ["all"] as LegacyFilterSpecification | ExpressionSpecification;
-
-    const isNestedCombiningFilter = displaySimpleFilter && hasNestedCombiningFilter(combiningFilter(this.props));
-
-    if (isNestedCombiningFilter) {
-      return <div className="maputnik-filter-editor-unsupported">
-        <p>
-          {t("Nested filters are not supported.")}
-        </p>
+    const actions = (
+      <div>
         <InputButton
-          onClick={this.makeExpression}
+          onClick={makeExpression}
           title={t("Convert to expression")}
+          className="maputnik-make-zoom-function"
+          data-wd-key="filter-convert-to-expression"
         >
           <TbMathFunction />
-          {t("Upgrade to expression")}
         </InputButton>
-      </div>;
-    }
-    else if (displaySimpleFilter) {
-      const filter = combiningFilter(this.props);
-      const combiningOp = filter[0];
-      const filters = filter.slice(1) as (LegacyFilterSpecification | ExpressionSpecification)[];
+      </div>
+    );
 
-      const actions = (
-        <div>
-          <InputButton
-            onClick={this.makeExpression}
-            title={t("Convert to expression")}
-            className="maputnik-make-zoom-function"
-            data-wd-key="filter-convert-to-expression"
-          >
-            <TbMathFunction />
-          </InputButton>
+    const editorBlocks = filters.map((f, idx) => {
+      const error = errors![`filter[${idx+1}]`];
+
+      return (
+        <div key={`block-${idx}`}>
+          <FilterEditorBlock key={idx} onDelete={deleteFilterItem.bind(null, idx)}>
+            <SingleFilterEditor
+              properties={props.properties}
+              filter={f}
+              onChange={onFilterPartChanged.bind(null, idx + 1)}
+            />
+          </FilterEditorBlock>
+          {error &&
+              <div key="error" className="maputnik-inline-error">{error.message}</div>
+          }
         </div>
       );
-
-      const editorBlocks = filters.map((f, idx) => {
-        const error = errors![`filter[${idx+1}]`];
-
-        return (
-          <div key={`block-${idx}`}>
-            <FilterEditorBlock key={idx} onDelete={this.deleteFilterItem.bind(this, idx)}>
-              <SingleFilterEditor
-                properties={this.props.properties}
-                filter={f}
-                onChange={this.onFilterPartChanged.bind(this, idx + 1)}
-              />
-            </FilterEditorBlock>
-            {error &&
-              <div key="error" className="maputnik-inline-error">{error.message}</div>
-            }
-          </div>
-        );
-      });
+    });
 
 
-      return (
-        <>
-          <Block
-            key="top"
-            fieldSpec={fieldSpec}
-            label={t("Filter")}
-            action={actions}
-            data-wd-key="filter-combining-operator"
-          >
-            <InputSelect
-              value={combiningOp}
-              onChange={(v: [string, any]) => this.onFilterPartChanged(0, v)}
-              options={[
-                ["all", t("every filter matches")],
-                ["none", t("no filter matches")],
-                ["any", t("any filter matches")]
-              ]}
-            />
-          </Block>
-          {editorBlocks}
-          <div
-            key="buttons"
-            className="maputnik-filter-editor-add-wrapper"
-          >
-            <InputButton
-              data-wd-key="layer-filter-button"
-              className="maputnik-add-filter"
-              onClick={this.addFilterItem}
-            >
-              <PiListPlusBold style={{ verticalAlign: "text-bottom" }} />
-              {t("Add filter")}
-            </InputButton>
-          </div>
-          <div
-            key="doc"
-            className="maputnik-doc-inline"
-            style={{display: this.state.showDoc ? "" : "none"}}
-          >
-            <Doc fieldSpec={fieldSpec} />
-          </div>
-        </>
-      );
-    }
-    else {
-      const {filter} = this.props;
-
-      return (
-        <>
-          <ExpressionProperty
-            onDelete={() => {
-              this.setState({displaySimpleFilter: true});
-              this.props.onChange(defaultFilter);
-            }}
-            fieldName="filter"
-            value={filter}
-            errors={errors}
-            onChange={this.props.onChange}
+    return (
+      <>
+        <Block
+          key="top"
+          fieldSpec={fieldSpec}
+          label={t("Filter")}
+          action={actions}
+          data-wd-key="filter-combining-operator"
+        >
+          <InputSelect
+            value={combiningOp}
+            onChange={(v: [string, any]) => onFilterPartChanged(0, v)}
+            options={[
+              ["all", t("every filter matches")],
+              ["none", t("no filter matches")],
+              ["any", t("any filter matches")]
+            ]}
           />
-          {this.state.valueIsSimpleFilter &&
+        </Block>
+        {editorBlocks}
+        <div
+          key="buttons"
+          className="maputnik-filter-editor-add-wrapper"
+        >
+          <InputButton
+            data-wd-key="layer-filter-button"
+            className="maputnik-add-filter"
+            onClick={addFilterItem}
+          >
+            <PiListPlusBold style={{ verticalAlign: "text-bottom" }} />
+            {t("Add filter")}
+          </InputButton>
+        </div>
+        <div
+          key="doc"
+          className="maputnik-doc-inline"
+          style={{display: showDoc ? "" : "none"}}
+        >
+          <Doc fieldSpec={fieldSpec} />
+        </div>
+      </>
+    );
+  }
+  else {
+    const {filter} = props;
+
+    return (
+      <>
+        <ExpressionProperty
+          onDelete={() => {
+            setDisplaySimpleFilter(true);
+            props.onChange(defaultFilter);
+          }}
+          fieldName="filter"
+          value={filter}
+          errors={errors}
+          onChange={props.onChange}
+        />
+        {valueIsSimpleFilter &&
             <div className="maputnik-expr-infobox">
               {t("You've entered an old style filter.")}
               {" "}
               <button
-                onClick={this.makeFilter}
+                onClick={makeFilter}
                 className="maputnik-expr-infobox__button"
               >
                 {t("Switch to filter editor.")}
               </button>
             </div>
-          }
-        </>
-      );
-    }
+        }
+      </>
+    );
   }
-}
+};
 
 export const FilterEditor = withTranslation()(FilterEditorInternal);

src/components/FilterEditorBlock.tsx

@@ -7,24 +7,22 @@ type FilterEditorBlockInternalProps = PropsWithChildren & {
   onDelete(...args: unknown[]): unknown
 } & WithTranslation;
 
-class FilterEditorBlockInternal extends React.Component<FilterEditorBlockInternalProps> {
-  render() {
-    const t = this.props.t;
-    return <div className="maputnik-filter-editor-block">
-      <div className="maputnik-filter-editor-block-content">
-        {this.props.children}
-      </div>
-      <div className="maputnik-filter-editor-block-action">
-        <InputButton
-          className="maputnik-icon-button"
-          onClick={this.props.onDelete}
-          title={t("Delete filter block")}
-        >
-          <MdDelete />
-        </InputButton>
-      </div>
-    </div>;
-  }
-}
+const FilterEditorBlockInternal: React.FC<FilterEditorBlockInternalProps> = (props) => {
+  const t = props.t;
+  return <div className="maputnik-filter-editor-block">
+    <div className="maputnik-filter-editor-block-content">
+      {props.children}
+    </div>
+    <div className="maputnik-filter-editor-block-action">
+      <InputButton
+        className="maputnik-icon-button"
+        onClick={props.onDelete}
+        title={t("Delete filter block")}
+      >
+        <MdDelete />
+      </InputButton>
+    </div>
+  </div>;
+};
 
 export const FilterEditorBlock = withTranslation()(FilterEditorBlockInternal);

src/components/FunctionButtons.tsx

@@ -13,58 +13,56 @@ type FunctionInputButtonsInternalProps = {
   onElevationClick?(): void
 } & WithTranslation;
 
-class FunctionInputButtonsInternal extends React.Component<FunctionInputButtonsInternalProps> {
-  render() {
-    const t = this.props.t;
+const FunctionInputButtonsInternal: React.FC<FunctionInputButtonsInternalProps> = (props) => {
+  const t = props.t;
 
-    if (this.props.fieldSpec.expression?.parameters.includes("zoom")) {
-      const expressionInputButton = (
-        <InputButton
-          className="maputnik-make-zoom-function"
-          onClick={this.props.onExpressionClick}
-          title={t("Convert to expression")}
-        >
-          <TbMathFunction />
-        </InputButton>
-      );
-
-      const makeZoomInputButton = <InputButton
+  if (props.fieldSpec.expression?.parameters.includes("zoom")) {
+    const expressionInputButton = (
+      <InputButton
         className="maputnik-make-zoom-function"
-        onClick={this.props.onZoomClick}
-        title={t("Convert property into a zoom function")}
+        onClick={props.onExpressionClick}
+        title={t("Convert to expression")}
       >
-        <MdFunctions />
-      </InputButton>;
+        <TbMathFunction />
+      </InputButton>
+    );
 
-      let makeDataInputButton;
-      if (this.props.fieldSpec["property-type"] === "data-driven") {
-        makeDataInputButton = <InputButton
-          className="maputnik-make-data-function"
-          onClick={this.props.onDataClick}
-          title={t("Convert property to data function")}
-        >
-          <MdInsertChart />
-        </InputButton>;
-      }
-      return <div>
-        {expressionInputButton}
-        {makeDataInputButton}
-        {makeZoomInputButton}
-      </div>;
-    } else if (this.props.fieldSpec.expression?.parameters.includes("elevation")) {
-      const inputElevationButton = <InputButton
-        className="maputnik-make-elevation-function"
-        onClick={this.props.onElevationClick}
-        title={t("Convert property into a elevation function")}
-        data-wd-key='make-elevation-function'
+    const makeZoomInputButton = <InputButton
+      className="maputnik-make-zoom-function"
+      onClick={props.onZoomClick}
+      title={t("Convert property into a zoom function")}
+    >
+      <MdFunctions />
+    </InputButton>;
+
+    let makeDataInputButton;
+    if (props.fieldSpec["property-type"] === "data-driven") {
+      makeDataInputButton = <InputButton
+        className="maputnik-make-data-function"
+        onClick={props.onDataClick}
+        title={t("Convert property to data function")}
       >
-        <MdFunctions />
+        <MdInsertChart />
       </InputButton>;
-      return <div>{inputElevationButton}</div>;
-    } else {
-      return <div></div>;
     }
+    return <div>
+      {expressionInputButton}
+      {makeDataInputButton}
+      {makeZoomInputButton}
+    </div>;
+  } else if (props.fieldSpec.expression?.parameters.includes("elevation")) {
+    const inputElevationButton = <InputButton
+      className="maputnik-make-elevation-function"
+      onClick={props.onElevationClick}
+      title={t("Convert property into a elevation function")}
+      data-wd-key='make-elevation-function'
+    >
+      <MdFunctions />
+    </InputButton>;
+    return <div>{inputElevationButton}</div>;
+  } else {
+    return <div></div>;
   }
-}
+};
 
 export const FunctionInputButtons = withTranslation()(FunctionInputButtonsInternal);

src/components/InputArray.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useState } from "react";
 import { InputString } from "./InputString";
 import { InputNumber } from "./InputNumber";
 
@@ -12,106 +12,72 @@ export type InputArrayProps = {
   label?: string
 };
 
-type InputArrayState = {
-  value: (string | number | undefined)[]
-  initialPropsValue: unknown[]
+export const InputArray: React.FC<InputArrayProps> = ({
+  value: propsValue = [],
+  default: propsDefault = [],
+  ...rest
+}) => {
+  const props = { value: propsValue, default: propsDefault, ...rest };
+
+  // The original seeded this from props and then never let props overwrite it
+  // again (its getDerivedStateFromProps assigned the existing state back in
+  // both branches), so the value is owned by this component after mount.
+  const [value, setValue] = useState<(string | number | undefined)[]>(() => propsValue.slice(0));
+
+  function isComplete(val: unknown[]) {
+    return Array(props.length).fill(null).every((_, i) => {
+      const v = val[i];
+      return !(v === undefined || v === "");
+    });
+  }
+
+  function changeValue(idx: number, newValue: string | number | undefined) {
+    const nextValue = value.slice(0);
+    nextValue[idx] = newValue;
+
+    setValue(nextValue);
+
+    if (isComplete(nextValue) && props.onChange) {
+      props.onChange(nextValue);
+    }
+    else if (props.onChange) {
+      // Unset until complete
+      props.onChange(undefined);
+    }
+  }
+
+  const containsValues = (
+    value.length > 0 &&
+    !value.every(val => {
+      return (val === "" || val === undefined);
+    })
+  );
+
+  const inputs = Array(props.length).fill(null).map((_, i) => {
+    if(props.type === "number") {
+      return <InputNumber
+        key={i}
+        default={containsValues || !props.default ? undefined : props.default[i] as number}
+        value={value[i] as number}
+        required={containsValues ? true : false}
+        onChange={(v) => changeValue(i, v)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    } else {
+      return <InputString
+        key={i}
+        default={containsValues || !props.default ? undefined : props.default[i] as string}
+        value={value[i] as string}
+        required={containsValues ? true : false}
+        onChange={(v) => changeValue(i, v)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    }
+  });
+
+  return (
+    <div className="maputnik-array">
+      {inputs}
+    </div>
+  );
 };
-
-export class InputArray extends React.Component<InputArrayProps, InputArrayState> {
-  static defaultProps = {
-    value: [],
-    default: [],
-  };
-
-  constructor (props: InputArrayProps) {
-    super(props);
-    this.state = {
-      value: this.props.value.slice(0),
-      // This is so we can compare changes in getDerivedStateFromProps
-      initialPropsValue: this.props.value.slice(0),
-    };
-  }
-
-  static getDerivedStateFromProps(props: Readonly<InputArrayProps>, state: InputArrayState) {
-    const value: any[] = [];
-    const initialPropsValue = state.initialPropsValue.slice(0);
-
-    Array(props.length).fill(null).map((_, i) => {
-      if (props.value[i] === state.initialPropsValue[i]) {
-        value[i] = state.value[i];
-      }
-      else {
-        value[i] = state.value[i];
-        initialPropsValue[i] = state.value[i];
-      }
-    });
-
-    return {
-      value,
-      initialPropsValue,
-    };
-  }
-
-  isComplete(value: unknown[]) {
-    return Array(this.props.length).fill(null).every((_, i) => {
-      const val = value[i];
-      return !(val === undefined || val === "");
-    });
-  }
-
-  changeValue(idx: number, newValue: string | number | undefined) {
-    const value = this.state.value.slice(0);
-    value[idx] = newValue;
-
-    this.setState({
-      value,
-    }, () => {
-      if (this.isComplete(value) && this.props.onChange) {
-        this.props.onChange(value);
-      }
-      else if (this.props.onChange){
-        // Unset until complete
-        this.props.onChange(undefined);
-      }
-    });
-  }
-
-  render() {
-    const {value} = this.state;
-
-    const containsValues = (
-      value.length > 0 &&
-      !value.every(val => {
-        return (val === "" || val === undefined);
-      })
-    );
-
-    const inputs = Array(this.props.length).fill(null).map((_, i) => {
-      if(this.props.type === "number") {
-        return <InputNumber
-          key={i}
-          default={containsValues || !this.props.default ? undefined : this.props.default[i] as number}
-          value={value[i] as number}
-          required={containsValues ? true : false}
-          onChange={(v) => this.changeValue(i, v)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      } else {
-        return <InputString
-          key={i}
-          default={containsValues || !this.props.default ? undefined : this.props.default[i] as string}
-          value={value[i] as string}
-          required={containsValues ? true : false}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
-    });
-
-    return (
-      <div className="maputnik-array">
-        {inputs}
-      </div>
-    );
-  }
-}

src/components/InputButton.tsx

@@ -14,20 +14,18 @@ type InputButtonProps = {
   title?: string
 };
 
-export class InputButton extends React.Component<InputButtonProps> {
-  render() {
-    return <button
-      id={this.props.id}
-      title={this.props.title}
-      type={this.props.type}
-      onClick={this.props.onClick}
-      disabled={this.props.disabled}
-      aria-label={this.props["aria-label"]}
-      className={classnames("maputnik-button", this.props.className)}
-      data-wd-key={this.props["data-wd-key"]}
-      style={this.props.style}
-    >
-      {this.props.children}
-    </button>;
-  }
-}
+export const InputButton: React.FC<InputButtonProps> = (props) => {
+  return <button
+    id={props.id}
+    title={props.title}
+    type={props.type}
+    onClick={props.onClick}
+    disabled={props.disabled}
+    aria-label={props["aria-label"]}
+    className={classnames("maputnik-button", props.className)}
+    data-wd-key={props["data-wd-key"]}
+    style={props.style}
+  >
+    {props.children}
+  </button>;
+};

src/components/InputCheckbox.tsx

@@ -6,32 +6,26 @@ export type InputCheckboxProps = {
   onChange(...args: unknown[]): unknown
 };
 
-export class InputCheckbox extends React.Component<InputCheckboxProps> {
-  static defaultProps = {
-    value: false,
+export const InputCheckbox: React.FC<InputCheckboxProps> = ({value = false, ...props}) => {
+  const onChange = () => {
+    props.onChange(!value);
   };
 
-  onChange = () => {
-    this.props.onChange(!this.props.value);
-  };
-
-  render() {
-    return <div className="maputnik-checkbox-wrapper">
-      <input
-        className="maputnik-checkbox"
-        type="checkbox"
-        style={this.props.style}
-        onChange={this.onChange}
-        onClick={this.onChange}
-        checked={this.props.value}
-      />
-      <div className="maputnik-checkbox-box">
-        <svg style={{
-          display: this.props.value ? "inline" : "none"
-        }} className="maputnik-checkbox-icon" viewBox='0 0 32 32'>
-          <path d='M1 14 L5 10 L13 18 L27 4 L31 8 L13 26 z' />
-        </svg>
-      </div>
-    </div>;
-  }
-}
+  return <div className="maputnik-checkbox-wrapper">
+    <input
+      className="maputnik-checkbox"
+      type="checkbox"
+      style={props.style}
+      onChange={onChange}
+      onClick={onChange}
+      checked={value}
+    />
+    <div className="maputnik-checkbox-box">
+      <svg style={{
+        display: value ? "inline" : "none"
+      }} className="maputnik-checkbox-icon" viewBox='0 0 32 32'>
+        <path d='M1 14 L5 10 L13 18 L27 4 L31 8 L13 26 z' />
+      </svg>
+    </div>
+  </div>;
+};

src/components/InputColor.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useEffect, useMemo, useRef, useState } from "react";
 import Color from "color";
 import ChromePicker from "react-color/lib/components/chrome/Chrome";
 import {type ColorResult} from "react-color";
@@ -20,26 +20,27 @@ export type InputColorProps = {
 };
 
 /*** Number fields with support for min, max and units and documentation*/
-export class InputColor extends React.Component<InputColorProps> {
-  state = {
-    pickerOpened: false
-  };
-  colorInput: HTMLInputElement | null = null;
+export const InputColor: React.FC<InputColorProps> = (props) => {
+  const [pickerOpened, setPickerOpened] = useState(false);
+  const colorInput = useRef<HTMLInputElement | null>(null);
 
-  constructor (props: InputColorProps) {
-    super(props);
-    this.onChangeNoCheck = lodash.throttle(this.onChangeNoCheck, 1000/30);
-  }
+  // Keep the latest `onChange` available to the throttled callback, which is
+  // created only once so that throttling actually takes effect.
+  const onChangeProp = useRef(props.onChange);
+  useEffect(() => {
+    onChangeProp.current = props.onChange;
+  });
 
-  onChangeNoCheck(v: string) {
-    this.props.onChange(v);
-  }
+  const onChangeNoCheck = useMemo(
+    () => lodash.throttle((v: string) => onChangeProp.current(v), 1000/30),
+    []
+  );
 
   //TODO: I much rather would do this with absolute positioning
   //but I am too stupid to get it to work together with fixed position
   //and scrollbars so I have to fallback to JavaScript
-  calcPickerOffset = () => {
-    const elem = this.colorInput;
+  const calcPickerOffset = () => {
+    const elem = colorInput.current;
     if(elem) {
       const pos = elem.getBoundingClientRect();
       return {
@@ -54,82 +55,80 @@ export class InputColor extends React.Component<InputColorProps> {
     }
   };
 
-  togglePicker = () => {
-    this.setState({ pickerOpened: !this.state.pickerOpened });
+  const togglePicker = () => {
+    setPickerOpened(opened => !opened);
   };
 
-  get color() {
+  const getColor = () => {
     // Catch invalid color.
     try {
-      return Color(this.props.value).rgb();
+      return Color(props.value).rgb();
     }
     catch(err) {
       console.warn("Error parsing color: ", err);
       return Color("rgb(255,255,255)");
     }
-  }
+  };
 
-  onChange (v: string) {
-    this.props.onChange(v === "" ? undefined : v);
-  }
+  const onChange = (v: string) => {
+    props.onChange(v === "" ? undefined : v);
+  };
 
-  render() {
-    const offset = this.calcPickerOffset();
-    const currentColor = this.color.object();
-    const currentChromeColor = {
-      r: currentColor.r,
-      g: currentColor.g,
-      b: currentColor.b,
-      // Rename alpha -> a for ChromePicker
-      a: currentColor.alpha!
-    };
+  const offset = calcPickerOffset();
+  const currentColor = getColor().object();
+  const currentChromeColor = {
+    r: currentColor.r,
+    g: currentColor.g,
+    b: currentColor.b,
+    // Rename alpha -> a for ChromePicker
+    a: currentColor.alpha!
+  };
 
-    const picker = <div
+  const picker = <div
+    className="maputnik-color-picker-offset"
+    style={{
+      position: "fixed",
+      zIndex: 1,
+      left: offset.left,
+      top: offset.top,
+    }}>
+    <ChromePicker
+      color={currentChromeColor}
+      onChange={c => onChangeNoCheck(formatColor(c))}
+    />
+    <div
       className="maputnik-color-picker-offset"
+      onClick={togglePicker}
       style={{
+        zIndex: -1,
         position: "fixed",
-        zIndex: 1,
-        left: offset.left,
-        top: offset.top,
-      }}>
-      <ChromePicker
-        color={currentChromeColor}
-        onChange={c => this.onChangeNoCheck(formatColor(c))}
-      />
-      <div
-        className="maputnik-color-picker-offset"
-        onClick={this.togglePicker}
-        style={{
-          zIndex: -1,
-          position: "fixed",
-          top: "0px",
-          right: "0px",
-          bottom: "0px",
-          left: "0px",
-        }}
-      />
-    </div>;
+        top: "0px",
+        right: "0px",
+        bottom: "0px",
+        left: "0px",
+      }}
+    />
+  </div>;
 
-    const swatchStyle = {
-      backgroundColor: this.props.value
-    };
+  const swatchStyle = {
+    backgroundColor: props.value
+  };
 
-    return <div className="maputnik-color-wrapper">
-      {this.state.pickerOpened && picker}
-      <div className="maputnik-color-swatch" style={swatchStyle}></div>
-      <input
-        aria-label={this.props["aria-label"]}
-        spellCheck="false"
-        autoComplete="off"
-        className="maputnik-color"
-        ref={(input) => {this.colorInput = input;}}
-        onClick={this.togglePicker}
-        style={this.props.style}
-        name={this.props.name}
-        placeholder={this.props.default}
-        value={this.props.value ? this.props.value : ""}
-        onChange={(e) => this.onChange(e.target.value)}
-      />
-    </div>;
-  }
-}
+  return <div className="maputnik-color-wrapper">
+    {pickerOpened && picker}
+    <div className="maputnik-color-swatch" style={swatchStyle}></div>
+    <input
+      aria-label={props["aria-label"]}
+      spellCheck="false"
+      autoComplete="off"
+      className="maputnik-color"
+      ref={colorInput}
+      onClick={togglePicker}
+      style={props.style}
+      name={props.name}
+      placeholder={props.default}
+      value={props.value ? props.value : ""}
+      onChange={(e) => onChange(e.target.value)}
+    />
+  </div>;
+};

src/components/InputDynamicArray.tsx

@@ -27,136 +27,130 @@ export type InputDynamicArrayProps = {
 
 type InputDynamicArrayInternalProps = InputDynamicArrayProps & WithTranslation;
 
-class InputDynamicArrayInternal extends React.Component<InputDynamicArrayInternalProps> {
-  changeValue(idx: number, newValue: string | number | undefined) {
-    const values = this.values.slice(0);
-    values[idx] = newValue;
-    if (this.props.onChange) this.props.onChange(values);
-  }
+const InputDynamicArrayInternal: React.FC<InputDynamicArrayInternalProps> = (props) => {
+  const values = props.value || props.default || [];
 
-  get values() {
-    return this.props.value || this.props.default || [];
-  }
-
-  addValue = () => {
-    const values = this.values.slice(0);
-    if (this.props.type === "number") {
-      values.push(0);
-    }
-    else if (this.props.type === "url") {
-      values.push("");
-    }
-    else if (this.props.type === "enum") {
-      const {fieldSpec} = this.props;
-      const defaultValue = Object.keys(fieldSpec!.values)[0];
-      values.push(defaultValue);
-    } else if (this.props.type === "color") {
-      values.push("#000000");
-    } else {
-      values.push("");
-    }
-
-    if (this.props.onChange) this.props.onChange(values);
+  const changeValue = (idx: number, newValue: string | number | undefined) => {
+    const newValues = values.slice(0);
+    newValues[idx] = newValue;
+    if (props.onChange) props.onChange(newValues);
   };
 
-  deleteValue(valueIdx: number) {
-    const values = this.values.slice(0);
-    values.splice(valueIdx, 1);
+  const addValue = () => {
+    const newValues = values.slice(0);
+    if (props.type === "number") {
+      newValues.push(0);
+    }
+    else if (props.type === "url") {
+      newValues.push("");
+    }
+    else if (props.type === "enum") {
+      const {fieldSpec} = props;
+      const defaultValue = Object.keys(fieldSpec!.values)[0];
+      newValues.push(defaultValue);
+    } else if (props.type === "color") {
+      newValues.push("#000000");
+    } else {
+      newValues.push("");
+    }
 
-    if (this.props.onChange) this.props.onChange(values.length > 0 ? values : undefined);
-  }
+    if (props.onChange) props.onChange(newValues);
+  };
 
-  render() {
-    const t = this.props.t;
-    const i18nProps = { t, i18n: this.props.i18n, tReady: this.props.tReady };
-    const inputs = this.values.map((v, i) => {
-      const deleteValueBtn= <DeleteValueInputButton
-        onClick={this.deleteValue.bind(this, i)}
-        {...i18nProps}
+  const deleteValue = (valueIdx: number) => {
+    const newValues = values.slice(0);
+    newValues.splice(valueIdx, 1);
+
+    if (props.onChange) props.onChange(newValues.length > 0 ? newValues : undefined);
+  };
+
+  const t = props.t;
+  const i18nProps = { t, i18n: props.i18n, tReady: props.tReady };
+  const inputs = values.map((v, i) => {
+    const deleteValueBtn= <DeleteValueInputButton
+      onClick={deleteValue.bind(null, i)}
+      {...i18nProps}
+    />;
+    let input;
+    if(props.type === "url") {
+      input = <InputUrl
+        value={v as string}
+        onChange={changeValue.bind(null, i)}
+        aria-label={props["aria-label"] || props.label}
       />;
-      let input;
-      if(this.props.type === "url") {
-        input = <InputUrl
-          value={v as string}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
-      else if (this.props.type === "number") {
-        input = <InputNumber
-          value={v as number}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
-      else if (this.props.type === "enum") {
-        const options = Object.keys(this.props.fieldSpec?.values).map(v => [v, capitalize(v)]);
-        input = <InputEnum
-          options={options}
-          value={v as string}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
-      else if (this.props.type === "color") {
-        input = <InputColor
-          value={v as string}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
-      else {
-        input = <InputString
-          value={v as string}
-          onChange={this.changeValue.bind(this, i)}
-          aria-label={this.props["aria-label"] || this.props.label}
-        />;
-      }
+    }
+    else if (props.type === "number") {
+      input = <InputNumber
+        value={v as number}
+        onChange={changeValue.bind(null, i)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    }
+    else if (props.type === "enum") {
+      const options = Object.keys(props.fieldSpec?.values).map(v => [v, capitalize(v)]);
+      input = <InputEnum
+        options={options}
+        value={v as string}
+        onChange={changeValue.bind(null, i)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    }
+    else if (props.type === "color") {
+      input = <InputColor
+        value={v as string}
+        onChange={changeValue.bind(null, i)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    }
+    else {
+      input = <InputString
+        value={v as string}
+        onChange={changeValue.bind(null, i)}
+        aria-label={props["aria-label"] || props.label}
+      />;
+    }
 
-      return <div
-        style={this.props.style}
-        key={i}
-        className="maputnik-array-block"
-      >
-        <div className="maputnik-array-block-action">
-          {deleteValueBtn}
-        </div>
-        <div className="maputnik-array-block-content">
-          {input}
-        </div>
-      </div>;
-    });
-
-    return (
-      <div className="maputnik-array">
-        {inputs}
-        <InputButton
-          className="maputnik-array-add-value"
-          onClick={this.addValue}
-        >
-          {t("Add value")}
-        </InputButton>
+    return <div
+      style={props.style}
+      key={i}
+      className="maputnik-array-block"
+    >
+      <div className="maputnik-array-block-action">
+        {deleteValueBtn}
       </div>
-    );
-  }
-}
+      <div className="maputnik-array-block-content">
+        {input}
+      </div>
+    </div>;
+  });
+
+  return (
+    <div className="maputnik-array">
+      {inputs}
+      <InputButton
+        className="maputnik-array-add-value"
+        onClick={addValue}
+      >
+        {t("Add value")}
+      </InputButton>
+    </div>
+  );
+};
 
 export const InputDynamicArray = withTranslation()(InputDynamicArrayInternal);
 type DeleteValueInputButtonProps = {
   onClick?(...args: unknown[]): unknown
 } & WithTranslation;
 
-class DeleteValueInputButton extends React.Component<DeleteValueInputButtonProps> {
-  render() {
-    const t = this.props.t;
-    return <InputButton
-      className="maputnik-delete-stop"
-      onClick={this.props.onClick}
-      title={t("Remove array item")}
-    >
-      <FieldDocLabel
-        label={<MdDelete />}
-      />
-    </InputButton>;
-  }
-}
+const DeleteValueInputButton: React.FC<DeleteValueInputButtonProps> = (props) => {
+  const t = props.t;
+  return <InputButton
+    className="maputnik-delete-stop"
+    onClick={props.onClick}
+    title={t("Remove array item")}
+  >
+    <FieldDocLabel
+      label={<MdDelete />}
+    />
+  </InputButton>;
+};

src/components/InputEnum.tsx

@@ -25,25 +25,23 @@ export type InputEnumProps = {
 };
 
 
-export class InputEnum extends React.Component<InputEnumProps> {
-  render() {
-    const {options, value, onChange, name, label} = this.props;
+export const InputEnum: React.FC<InputEnumProps> = (props) => {
+  const {options, value, onChange, name, label} = props;
 
-    if(options.length <= 3 && optionsLabelLength(options) <= 20) {
-      return <InputMultiInput
-        name={name}
-        options={options}
-        value={(value || this.props.default)!}
-        onChange={onChange}
-        aria-label={this.props["aria-label"] || label}
-      />;
-    } else {
-      return <InputSelect
-        options={options}
-        value={(value || this.props.default)!}
-        onChange={onChange}
-        aria-label={this.props["aria-label"] || label}
-      />;
-    }
+  if(options.length <= 3 && optionsLabelLength(options) <= 20) {
+    return <InputMultiInput
+      name={name}
+      options={options}
+      value={(value || props.default)!}
+      onChange={onChange}
+      aria-label={props["aria-label"] || label}
+    />;
+  } else {
+    return <InputSelect
+      options={options}
+      value={(value || props.default)!}
+      onChange={onChange}
+      aria-label={props["aria-label"] || label}
+    />;
   }
-}
+};

src/components/InputFont.tsx

@@ -11,13 +11,9 @@ export type InputFontProps = {
   "aria-label"?: string
 };
 
-export class InputFont extends React.Component<InputFontProps> {
-  static defaultProps = {
-    fonts: []
-  };
-
-  get values() {
-    const out = this.props.value || this.props.default || [];
+export const InputFont: React.FC<InputFontProps> = ({fonts = [], ...props}) => {
+  const getValues = () => {
+    const out = props.value || props.default || [];
 
     // Always put a "" in the last field to you can keep adding entries
     if (out[out.length-1] !== ""){
@@ -26,36 +22,36 @@ export class InputFont extends React.Component<InputFontProps> {
     else {
       return out;
     }
-  }
+  };
 
-  changeFont(idx: number, newValue: string) {
-    const changedValues = this.values.slice(0);
+  const values = getValues();
+
+  const changeFont = (idx: number, newValue: string) => {
+    const changedValues = values.slice(0);
     changedValues[idx] = newValue;
     const filteredValues = changedValues
       .filter(v => v !== undefined)
       .filter(v => v !== "");
 
-    this.props.onChange(filteredValues);
-  }
+    props.onChange(filteredValues);
+  };
 
-  render() {
-    const inputs = this.values.map((value, i) => {
-      return <li
-        key={i}
-      >
-        <InputAutocomplete
-          aria-label={this.props["aria-label"] || this.props.name}
-          value={value}
-          options={this.props.fonts?.map(f => [f, f])}
-          onChange={this.changeFont.bind(this, i)}
-        />
-      </li>;
-    });
+  const inputs = values.map((value, i) => {
+    return <li
+      key={i}
+    >
+      <InputAutocomplete
+        aria-label={props["aria-label"] || props.name}
+        value={value}
+        options={fonts.map(f => [f, f])}
+        onChange={changeFont.bind(null, i)}
+      />
+    </li>;
+  });
 
-    return (
-      <ul className="maputnik-font">
-        {inputs}
-      </ul>
-    );
-  }
-}
+  return (
+    <ul className="maputnik-font">
+      {inputs}
+    </ul>
+  );
+};

src/components/InputJson.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useEffect, useRef } from "react";
 import classnames from "classnames";
 import { type WithTranslation, withTranslation } from "react-i18next";
 
@@ -25,88 +25,49 @@ export type InputJsonProps = {
 };
 type InputJsonInternalProps = InputJsonProps & WithTranslation;
 
-type InputJsonState = {
-  isEditing: boolean
-  prevValue: string
-};
+function getPrettyJson(data: any) {
+  return stringifyPretty(data, {indent: 2, maxLength: 40});
+}
 
-class InputJsonInternal extends React.Component<InputJsonInternalProps, InputJsonState> {
-  static defaultProps = {
-    onFocus: () => {},
-    onBlur: () => {},
-    withScroll: false
-  };
-  _view: EditorView | undefined;
-  _el: HTMLDivElement | null = null;
-  _cancelNextChange: boolean = false;
+const InputJsonInternal: React.FC<InputJsonInternalProps> = ({
+  value,
+  className,
+  onChange,
+  onFocus = () => {},
+  onBlur = () => {},
+  lintType,
+  spec,
+  withScroll = false,
+}) => {
+  const el = useRef<HTMLDivElement | null>(null);
+  const view = useRef<EditorView | undefined>(undefined);
+  const cancelNextChange = useRef<boolean>(false);
+  // `isEditing` and `prevValue` are never rendered, they are only read from the
+  // CodeMirror callbacks, so refs keep them up to date without re-rendering.
+  const isEditing = useRef<boolean>(false);
+  const prevValue = useRef<string>(getPrettyJson(value));
+  // Mirrors `prevProps.value` from the previous `componentDidUpdate`.
+  const prevValueProp = useRef<object>(value);
 
-  constructor(props: InputJsonInternalProps) {
-    super(props);
-    this.state = {
-      isEditing: false,
-      prevValue: this.getPrettyJson(this.props.value),
-    };
-  }
-
-  getPrettyJson(data: any) {
-    return stringifyPretty(data, {indent: 2, maxLength: 40});
-  }
-
-  componentDidMount () {
-    this._view = createEditor({
-      parent: this._el!,
-      value: this.getPrettyJson(this.props.value),
-      lintType: this.props.lintType || "layer",
-      onChange: (value:string) => this.onChange(value),
-      onFocus: () => this.onFocus(),
-      onBlur: () => this.onBlur(),
-      spec: this.props.spec
-    });
-  }
-
-  onFocus = () => {
-    if (this.props.onFocus) this.props.onFocus();
-    this.setState({
-      isEditing: true,
-    });
+  const handleFocus = () => {
+    if (onFocus) onFocus();
+    isEditing.current = true;
   };
 
-  onBlur = () => {
-    if (this.props.onBlur) this.props.onBlur();
-    this.setState({
-      isEditing: false,
-    });
+  const handleBlur = () => {
+    if (onBlur) onBlur();
+    isEditing.current = false;
   };
 
-  componentDidUpdate(prevProps: InputJsonProps) {
-    if (!this.state.isEditing && prevProps.value !== this.props.value) {
-      this._cancelNextChange = true;
-      const transactionSpec: TransactionSpec = {
-        changes: {
-          from: 0,
-          to: this._view!.state.doc.length,
-          insert: this.getPrettyJson(this.props.value)
-        }
-      };
-      if (this.props.withScroll) {
-        transactionSpec.selection = this._view!.state.selection;
-        transactionSpec.scrollIntoView = true;
-      }
-      this._view!.dispatch(transactionSpec);
-    }
-  }
-
-  onChange = (_e: unknown) => {
-    if (this._cancelNextChange) {
-      this._cancelNextChange = false;
-      this.setState({
-        prevValue: this._view!.state.doc.toString(),
-      });
+  const handleChange = () => {
+    if (cancelNextChange.current) {
+      cancelNextChange.current = false;
+      prevValue.current = view.current!.state.doc.toString();
       return;
     }
-    const newCode = this._view!.state.doc.toString();
+    const newCode = view.current!.state.doc.toString();
 
-    if (this.state.prevValue !== newCode) {
+    if (prevValue.current !== newCode) {
       let parsedLayer, err;
       try {
         parsedLayer = JSON.parse(newCode);
@@ -116,23 +77,63 @@ class InputJsonInternal extends React.Component<InputJsonInternalProps, InputJso
       }
 
       if (!err) {
-        if (this.props.onChange) this.props.onChange(parsedLayer);
+        if (onChange) onChange(parsedLayer);
       }
     }
 
-    this.setState({
-      prevValue: newCode,
-    });
+    prevValue.current = newCode;
   };
 
-  render() {
-    return <div className="json-editor" data-wd-key="json-editor" aria-hidden="true" style={{cursor: "text"}}>
-      <div
-        className={classnames("codemirror-container", this.props.className)}
-        ref={(el) => {this._el = el;}}
-      />
-    </div>;
-  }
-}
+  // The editor is created once on mount, so its callbacks have to go through a
+  // ref to always see the latest props.
+  const handlers = useRef({handleChange, handleFocus, handleBlur});
+  useEffect(() => {
+    handlers.current = {handleChange, handleFocus, handleBlur};
+  });
+
+  useEffect(() => {
+    view.current = createEditor({
+      parent: el.current!,
+      value: getPrettyJson(value),
+      lintType: lintType || "layer",
+      onChange: () => handlers.current.handleChange(),
+      onFocus: () => handlers.current.handleFocus(),
+      onBlur: () => handlers.current.handleBlur(),
+      spec: spec
+    });
+    // Runs once on mount, mirroring the previous componentDidMount.
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- mount-only: adding deps would rebuild the editor on every change
+  }, []);
+
+  useEffect(() => {
+    // Only react to an actual change of the `value` prop, which also skips the
+    // initial mount (the editor is created with the value already).
+    if (prevValueProp.current === value) return;
+    prevValueProp.current = value;
+
+    if (isEditing.current) return;
+
+    cancelNextChange.current = true;
+    const transactionSpec: TransactionSpec = {
+      changes: {
+        from: 0,
+        to: view.current!.state.doc.length,
+        insert: getPrettyJson(value)
+      }
+    };
+    if (withScroll) {
+      transactionSpec.selection = view.current!.state.selection;
+      transactionSpec.scrollIntoView = true;
+    }
+    view.current!.dispatch(transactionSpec);
+  }, [value, withScroll]);
+
+  return <div className="json-editor" data-wd-key="json-editor" aria-hidden="true" style={{cursor: "text"}}>
+    <div
+      className={classnames("codemirror-container", className)}
+      ref={el}
+    />
+  </div>;
+};
 
 export const InputJson = withTranslation()(InputJsonInternal);

src/components/InputMultiInput.tsx

@@ -9,31 +9,29 @@ export type InputMultiInputProps = {
   "aria-label"?: string
 };
 
-export class InputMultiInput extends React.Component<InputMultiInputProps> {
-  render() {
-    let options = this.props.options;
-    if(options.length > 0 && !Array.isArray(options[0])) {
-      options = options.map(v => [v, v]);
-    }
-
-    const selectedValue = this.props.value || options[0][0];
-    const radios = options.map(([val, label])=> {
-      return <label
-        key={val}
-        className={classnames("maputnik-button", "maputnik-radio-as-button", {"maputnik-button-selected": val === selectedValue})}
-      >
-        <input type="radio"
-          name={this.props.name}
-          onChange={_e => this.props.onChange(val)}
-          value={val}
-          checked={val === selectedValue}
-        />
-        {label}
-      </label>;
-    });
-
-    return <fieldset className="maputnik-multibutton" aria-label={this.props["aria-label"]}>
-      {radios}
-    </fieldset>;
+export const InputMultiInput: React.FC<InputMultiInputProps> = (props) => {
+  let options = props.options;
+  if(options.length > 0 && !Array.isArray(options[0])) {
+    options = options.map(v => [v, v]);
   }
-}
+
+  const selectedValue = props.value || options[0][0];
+  const radios = options.map(([val, label])=> {
+    return <label
+      key={val}
+      className={classnames("maputnik-button", "maputnik-radio-as-button", {"maputnik-button-selected": val === selectedValue})}
+    >
+      <input type="radio"
+        name={props.name}
+        onChange={_e => props.onChange(val)}
+        value={val}
+        checked={val === selectedValue}
+      />
+      {label}
+    </label>;
+  });
+
+  return <fieldset className="maputnik-multibutton" aria-label={props["aria-label"]}>
+    {radios}
+  </fieldset>;
+};

src/components/InputNumber.tsx

@@ -1,5 +1,4 @@
-import React, { type BaseSyntheticEvent } from "react";
-import { generateUniqueId } from "../libs/document-uid";
+import React, { type BaseSyntheticEvent, useRef, useState } from "react";
 
 export type InputNumberProps = {
   value?: number
@@ -14,233 +13,206 @@ export type InputNumberProps = {
   "aria-label"?: string
 };
 
-type InputNumberState = {
-  uuid: number
-  editing: boolean
-  editingRange?: boolean
-  value?: number
-  /**
-   * This is the value that is currently being edited. It can be an invalid value.
-   */
-  dirtyValue?: number | string | undefined
-};
+export const InputNumber: React.FC<InputNumberProps> = (props) => {
+  const { rangeStep = 1 } = props;
 
-export class InputNumber extends React.Component<InputNumberProps, InputNumberState> {
-  static defaultProps = {
-    rangeStep: 1
-  };
-  _keyboardEvent: boolean = false;
+  const [editing, setEditing] = useState(false);
+  const [editingRange, setEditingRange] = useState(false);
+  const [value, setValue] = useState<number | undefined>(props.value);
+  /** The value currently being edited. It can be an invalid value. */
+  const [dirtyValue, setDirtyValue] = useState<number | string | undefined>(props.value);
 
-  constructor(props: InputNumberProps) {
-    super(props);
-    this.state = {
-      uuid: +generateUniqueId(),
-      editing: false,
-      value: props.value,
-      dirtyValue: props.value,
-    };
+  const keyboardEvent = useRef(false);
+
+  // Replaces getDerivedStateFromProps: while not editing, track the prop.
+  if (!editing && props.value !== value) {
+    setValue(props.value);
+    setDirtyValue(props.value);
   }
 
-  static getDerivedStateFromProps(props: Readonly<InputNumberProps>, state: InputNumberState) {
-    if (!state.editing && props.value !== state.value) {
-      return {
-        value: props.value,
-        dirtyValue: props.value,
-      };
-    }
-    return null;
-  }
-
-  changeValue(newValue: number | string | undefined) {
-    const value = (newValue === "" || newValue === undefined) ?
-      undefined : +newValue;
-
-    const hasChanged = this.props.value !== value;
-    if(this.isValid(value) && hasChanged) {
-      if (this.props.onChange) this.props.onChange(value);
-      this.setState({
-        value: value,
-      });
-    }
-    else if (!this.isValid(value) && hasChanged) {
-      this.setState({
-        value: undefined,
-      });
-    }
-
-    this.setState({
-      dirtyValue: newValue === "" ? undefined : newValue,
-    });
-  }
-
-  isValid(v: number | string | undefined) {
+  function isValid(v: number | string | undefined) {
     if (v === undefined) {
       return true;
     }
 
-    const value = +v;
-    if(isNaN(value)) {
+    const val = +v;
+    if(isNaN(val)) {
       return false;
     }
 
-    if(!isNaN(this.props.min!) && value < this.props.min!) {
+    if(!isNaN(props.min!) && val < props.min!) {
       return false;
     }
 
-    if(!isNaN(this.props.max!) && value > this.props.max!) {
+    if(!isNaN(props.max!) && val > props.max!) {
       return false;
     }
 
     return true;
   }
 
-  resetValue = () => {
-    this.setState({editing: false});
+  function changeValue(newValue: number | string | undefined) {
+    const val = (newValue === "" || newValue === undefined) ?
+      undefined : +newValue;
+
+    const hasChanged = props.value !== val;
+    if(isValid(val) && hasChanged) {
+      if (props.onChange) props.onChange(val);
+      setValue(val);
+    }
+    else if (!isValid(val) && hasChanged) {
+      setValue(undefined);
+    }
+
+    setDirtyValue(newValue === "" ? undefined : newValue);
+  }
+
+  const resetValue = () => {
+    setEditing(false);
     // Reset explicitly to default value if value has been cleared
-    if(!this.state.value) {
+    if(!value) {
       return;
     }
 
     // If set value is invalid fall back to the last valid value from props or at last resort the default value
-    if (!this.isValid(this.state.value)) {
-      if(this.isValid(this.props.value)) {
-        this.changeValue(this.props.value);
-        this.setState({dirtyValue: this.props.value});
+    if (!isValid(value)) {
+      if(isValid(props.value)) {
+        changeValue(props.value);
+        setDirtyValue(props.value);
       } else {
-        this.changeValue(undefined);
-        this.setState({dirtyValue: undefined});
+        changeValue(undefined);
+        setDirtyValue(undefined);
       }
     }
   };
 
-  onChangeRange = (e: BaseSyntheticEvent<Event, HTMLInputElement, HTMLInputElement>) => {
-    let value = parseFloat(e.target.value);
-    const step = this.props.rangeStep;
-    let dirtyValue = value;
+  const onChangeRange = (e: BaseSyntheticEvent<Event, HTMLInputElement, HTMLInputElement>) => {
+    let newValue = parseFloat(e.target.value);
+    const step = rangeStep;
+    let newDirtyValue = newValue;
 
     if(step) {
       // Can't do this with the <input/> range step attribute else we won't be able to set a high precision value via the text input.
-      const snap = value % step;
+      const snap = newValue % step;
 
       // Round up/down to step
-      if (this._keyboardEvent) {
+      if (keyboardEvent.current) {
         // If it's keyboard event we might get a low positive/negative value,
         // for example we might go from 13 to 13.23, however because we know
         // that came from a keyboard event we always want to increase by a
         // single step value.
-        if (value < +this.state.dirtyValue!) {
-          value = this.state.value! - step;
+        if (newValue < +dirtyValue!) {
+          newValue = value! - step;
         }
         else {
-          value = this.state.value! + step;
+          newValue = value! + step;
         }
-        dirtyValue = value;
+        newDirtyValue = newValue;
       }
       else {
         if (snap < step/2) {
-          value = value - snap;
+          newValue = newValue - snap;
         }
         else {
-          value = value + (step - snap);
+          newValue = newValue + (step - snap);
         }
       }
     }
 
-    this._keyboardEvent = false;
+    keyboardEvent.current = false;
 
     // Clamp between min/max
-    value = Math.max(this.props.min!, Math.min(this.props.max!, value));
+    newValue = Math.max(props.min!, Math.min(props.max!, newValue));
 
-    this.setState({value, dirtyValue});
-    if (this.props.onChange) this.props.onChange(value);
+    setValue(newValue);
+    setDirtyValue(newDirtyValue);
+    if (props.onChange) props.onChange(newValue);
   };
 
-  render() {
-    if(
-      Object.prototype.hasOwnProperty.call(this.props, "min") &&
-      Object.prototype.hasOwnProperty.call(this.props, "max") &&
-      this.props.min !== undefined && this.props.max !== undefined &&
-      this.props.allowRange
-    ) {
-      const value = this.state.editing ? this.state.dirtyValue : this.state.value;
-      const defaultValue = this.props.default === undefined ? "" : this.props.default;
-      let inputValue;
-      if (this.state.editingRange) {
-        inputValue = this.state.value;
-      }
-      else {
-        inputValue = value;
-      }
-
-      return <div className="maputnik-number-container">
-        <input
-          className="maputnik-number-range"
-          key="range"
-          type="range"
-          max={this.props.max}
-          min={this.props.min}
-          step="any"
-          spellCheck="false"
-          value={value === undefined ? defaultValue : value}
-          onChange={this.onChangeRange}
-          onKeyDown={() => {
-            this._keyboardEvent = true;
-          }}
-          onPointerDown={() => {
-            this.setState({editing: true, editingRange: true});
-          }}
-          onPointerUp={() => {
-            // Safari doesn't get onBlur event
-            this.setState({editing: false, editingRange: false});
-          }}
-          onBlur={() => {
-            this.setState({
-              editing: false,
-              editingRange: false,
-              dirtyValue: this.state.value,
-            });
-          }}
-          data-wd-key={this.props["data-wd-key"] + "-range"}
-        />
-        <input
-          key="text"
-          type="text"
-          spellCheck="false"
-          className="maputnik-number"
-          placeholder={this.props.default?.toString()}
-          value={inputValue === undefined ? "" : inputValue}
-          onFocus={_e => {
-            this.setState({editing: true});
-          }}
-          onChange={e => {
-            this.changeValue(e.target.value);
-          }}
-          onBlur={_e => {
-            this.setState({editing: false});
-            this.resetValue();
-          }}
-          data-wd-key={this.props["data-wd-key"] + "-text"}
-
-        />
-      </div>;
+  if(
+    Object.prototype.hasOwnProperty.call(props, "min") &&
+    Object.prototype.hasOwnProperty.call(props, "max") &&
+    props.min !== undefined && props.max !== undefined &&
+    props.allowRange
+  ) {
+    const currentValue = editing ? dirtyValue : value;
+    const defaultValue = props.default === undefined ? "" : props.default;
+    let inputValue;
+    if (editingRange) {
+      inputValue = value;
     }
     else {
-      const value = this.state.editing ? this.state.dirtyValue : this.state.value;
+      inputValue = currentValue;
+    }
 
-      return <input
-        aria-label={this.props["aria-label"]}
+    return <div className="maputnik-number-container">
+      <input
+        className="maputnik-number-range"
+        key="range"
+        type="range"
+        max={props.max}
+        min={props.min}
+        step="any"
+        spellCheck="false"
+        value={currentValue === undefined ? defaultValue : currentValue}
+        onChange={onChangeRange}
+        onKeyDown={() => {
+          keyboardEvent.current = true;
+        }}
+        onPointerDown={() => {
+          setEditing(true);
+          setEditingRange(true);
+        }}
+        onPointerUp={() => {
+          // Safari doesn't get onBlur event
+          setEditing(false);
+          setEditingRange(false);
+        }}
+        onBlur={() => {
+          setEditing(false);
+          setEditingRange(false);
+          setDirtyValue(value);
+        }}
+        data-wd-key={props["data-wd-key"] + "-range"}
+      />
+      <input
+        key="text"
+        type="text"
         spellCheck="false"
         className="maputnik-number"
-        placeholder={this.props.default?.toString()}
-        value={value === undefined ? "" : value}
-        onChange={e => this.changeValue(e.target.value)}
-        onFocus={() => {
-          this.setState({editing: true});
+        placeholder={props.default?.toString()}
+        value={inputValue === undefined ? "" : inputValue}
+        onFocus={_e => {
+          setEditing(true);
         }}
-        onBlur={this.resetValue}
-        required={this.props.required}
-        data-wd-key={this.props["data-wd-key"]}
-      />;
-    }
+        onChange={e => {
+          changeValue(e.target.value);
+        }}
+        onBlur={_e => {
+          setEditing(false);
+          resetValue();
+        }}
+        data-wd-key={props["data-wd-key"] + "-text"}
+
+      />
+    </div>;
   }
-}
+  else {
+    const currentValue = editing ? dirtyValue : value;
+
+    return <input
+      aria-label={props["aria-label"]}
+      spellCheck="false"
+      className="maputnik-number"
+      placeholder={props.default?.toString()}
+      value={currentValue === undefined ? "" : currentValue}
+      onChange={e => changeValue(e.target.value)}
+      onFocus={() => {
+        setEditing(true);
+      }}
+      onBlur={resetValue}
+      required={props.required}
+      data-wd-key={props["data-wd-key"]}
+    />;
+  }
+};

src/components/InputSelect.tsx

@@ -10,23 +10,21 @@ export type InputSelectProps = {
   "aria-label"?: string
 };
 
-export class InputSelect extends React.Component<InputSelectProps> {
-  render() {
-    let options = this.props.options;
-    if(options.length > 0 && !Array.isArray(options[0])) {
-      options = options.map((v) => [v, v]) as [string, any][];
-    }
-
-    return <select
-      className="maputnik-select"
-      data-wd-key={this.props["data-wd-key"]}
-      style={this.props.style}
-      title={this.props.title}
-      value={this.props.value}
-      onChange={e => this.props.onChange(e.target.value)}
-      aria-label={this.props["aria-label"]}
-    >
-      { options.map(([val, label]) => <option key={val} value={val}>{label}</option>) }
-    </select>;
+export const InputSelect: React.FC<InputSelectProps> = (props) => {
+  let options = props.options;
+  if(options.length > 0 && !Array.isArray(options[0])) {
+    options = options.map((v) => [v, v]) as [string, any][];
   }
-}
+
+  return <select
+    className="maputnik-select"
+    data-wd-key={props["data-wd-key"]}
+    style={props.style}
+    title={props.title}
+    value={props.value}
+    onChange={e => props.onChange(e.target.value)}
+    aria-label={props["aria-label"]}
+  >
+    { options.map(([val, label]) => <option key={val} value={val}>{label}</option>) }
+  </select>;
+};

src/components/InputSpec.tsx

@@ -38,31 +38,31 @@ export type InputSpecProps = {
 /** Display any field from the Maplibre GL style spec and
  * choose the correct field component based on the @{fieldSpec}
  * to display @{value}. */
-export class InputSpec extends React.Component<InputSpecProps> {
+export const InputSpec: React.FC<InputSpecProps> = (props) => {
 
-  childNodes() {
+  const childNodes = () => {
     const commonProps = {
-      fieldSpec: this.props.fieldSpec,
-      label: this.props.label,
-      action: this.props.action,
-      style: this.props.style,
-      value: this.props.value,
-      default: this.props.fieldSpec?.default,
-      name: this.props.fieldName,
-      "data-wd-key": "spec-field-input:" + this.props.fieldName,
-      onChange: (newValue: number | undefined | (string | number | undefined)[]) => this.props.onChange!(this.props.fieldName, newValue),
-      "aria-label": this.props["aria-label"],
+      fieldSpec: props.fieldSpec,
+      label: props.label,
+      action: props.action,
+      style: props.style,
+      value: props.value,
+      default: props.fieldSpec?.default,
+      name: props.fieldName,
+      "data-wd-key": "spec-field-input:" + props.fieldName,
+      onChange: (newValue: number | undefined | (string | number | undefined)[]) => props.onChange!(props.fieldName, newValue),
+      "aria-label": props["aria-label"],
     };
-    switch(this.props.fieldSpec?.type) {
+    switch(props.fieldSpec?.type) {
       case "number": return (
         <InputNumber
           {...commonProps as InputNumberProps}
-          min={this.props.fieldSpec.minimum}
-          max={this.props.fieldSpec.maximum}
+          min={props.fieldSpec.minimum}
+          max={props.fieldSpec.maximum}
         />
       );
       case "enum": {
-        const options = Object.keys(this.props.fieldSpec.values || []).map(v => [v, capitalize(v)]);
+        const options = Object.keys(props.fieldSpec.values || []).map(v => [v, capitalize(v)]);
 
         return <InputEnum
           {...commonProps as Omit<InputEnumProps, "options">}
@@ -72,8 +72,8 @@ export class InputSpec extends React.Component<InputSpecProps> {
       case "resolvedImage":
       case "formatted":
       case "string":
-        if (iconProperties.indexOf(this.props.fieldName!) >= 0) {
-          const options = this.props.fieldSpec.values || [];
+        if (iconProperties.indexOf(props.fieldName!) >= 0) {
+          const options = props.fieldSpec.values || [];
           return <InputAutocomplete
             {...commonProps as Omit<InputAutocompleteProps, "options">}
             options={options.map(f => [f, f])}
@@ -94,61 +94,59 @@ export class InputSpec extends React.Component<InputSpecProps> {
         />
       );
       case "array":
-        if(this.props.fieldName === "text-font") {
+        if(props.fieldName === "text-font") {
           return <InputFont
             {...commonProps as InputFontProps}
-            fonts={this.props.fieldSpec.values}
+            fonts={props.fieldSpec.values}
           />;
         } else {
-          if (this.props.fieldSpec.length) {
+          if (props.fieldSpec.length) {
             return <InputArray
               {...commonProps as InputArrayProps}
-              type={this.props.fieldSpec.value}
-              length={this.props.fieldSpec.length}
+              type={props.fieldSpec.value}
+              length={props.fieldSpec.length}
             />;
           } else {
             return <InputDynamicArray
               {...commonProps as InputDynamicArrayProps}
-              fieldSpec={this.props.fieldSpec}
-              type={this.props.fieldSpec.value as InputDynamicArrayProps["type"]}
+              fieldSpec={props.fieldSpec}
+              type={props.fieldSpec.value as InputDynamicArrayProps["type"]}
             />;
           }
         }
       case "numberArray": return (
         <InputDynamicArray
           {...commonProps as InputDynamicArrayProps}
-          fieldSpec={this.props.fieldSpec}
+          fieldSpec={props.fieldSpec}
           type="number"
-          value={(Array.isArray(this.props.value) ? this.props.value : [this.props.value]) as (string | number | undefined)[]}
+          value={(Array.isArray(props.value) ? props.value : [props.value]) as (string | number | undefined)[]}
         />
       );
       case "colorArray": return (
         <InputDynamicArray
           {...commonProps as InputDynamicArrayProps}
-          fieldSpec={this.props.fieldSpec}
+          fieldSpec={props.fieldSpec}
           type="color"
-          value={(Array.isArray(this.props.value) ? this.props.value : [this.props.value]) as (string | number | undefined)[]}
+          value={(Array.isArray(props.value) ? props.value : [props.value]) as (string | number | undefined)[]}
         />
       );
       case "padding": return (
         <InputArray
           {...commonProps as InputArrayProps}
           type="number"
-          value={(Array.isArray(this.props.value) ? this.props.value : [this.props.value]) as (string | number | undefined)[]}
+          value={(Array.isArray(props.value) ? props.value : [props.value]) as (string | number | undefined)[]}
           length={4}
         />
       );
       default:
-        console.warn(`No proper field input for ${this.props.fieldName} type: ${this.props.fieldSpec?.type}`);
+        console.warn(`No proper field input for ${props.fieldName} type: ${props.fieldSpec?.type}`);
         return null;
     }
-  }
+  };
 
-  render() {
-    return (
-      <div data-wd-key={"spec-field:"+this.props.fieldName}>
-        {this.childNodes()}
-      </div>
-    );
-  }
-}
+  return (
+    <div data-wd-key={"spec-field:"+props.fieldName}>
+      {childNodes()}
+    </div>
+  );
+};

src/components/InputString.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useState } from "react";
 
 export type InputStringProps = {
   "data-wd-key"?: string
@@ -15,85 +15,66 @@ export type InputStringProps = {
   title?: string
 };
 
-type InputStringState = {
-  editing: boolean
-  value?: string
+export const InputString: React.FC<InputStringProps> = (props) => {
+  const { onInput = () => {} } = props;
+  const [editing, setEditing] = useState(false);
+  const [value, setValue] = useState<string | undefined>(props.value);
+
+  // Replaces getDerivedStateFromProps: while the field is not being edited its
+  // value tracks the prop, so an external change to the style is picked up.
+  if (!editing && value !== props.value) {
+    setValue(props.value);
+  }
+
+  let tag;
+  let classes;
+
+  if(props.multi) {
+    tag = "textarea";
+    classes = [
+      "maputnik-string",
+      "maputnik-string--multi"
+    ];
+  }
+  else {
+    tag = "input";
+    classes = [
+      "maputnik-string"
+    ];
+  }
+
+  if(props.disabled) {
+    classes.push("maputnik-string--disabled");
+  }
+
+  return React.createElement(tag, {
+    "aria-label": props["aria-label"],
+    "data-wd-key": props["data-wd-key"],
+    spellCheck: Object.prototype.hasOwnProperty.call(props, "spellCheck") ? props.spellCheck : !(tag === "input"),
+    disabled: props.disabled,
+    className: classes.join(" "),
+    style: props.style,
+    value: value === undefined ? "" : value,
+    placeholder: props.default,
+    title: props.title,
+    onChange: (e: React.BaseSyntheticEvent<Event, HTMLInputElement, HTMLInputElement>) => {
+      setEditing(true);
+      setValue(e.target.value);
+      onInput(e.target.value);
+    },
+    onBlur: () => {
+      // Note: editing is only cleared when the value actually changed; this
+      // mirrors the original and keeps a no-op blur from resyncing the value.
+      if(value !== props.value) {
+        setEditing(false);
+        if (props.onChange) props.onChange(value);
+      }
+    },
+    onKeyDown: (e: React.KeyboardEvent) => {
+      if (e.keyCode === 13 && props.onChange) {
+        props.onChange(value);
+      }
+    },
+    required: props.required,
+  });
 };
-
-export class InputString extends React.Component<InputStringProps, InputStringState> {
-  static defaultProps = {
-    onInput: () => {},
-  };
-
-  constructor(props: InputStringProps) {
-    super(props);
-    this.state = {
-      editing: false,
-      value: props.value || ""
-    };
-  }
-
-  static getDerivedStateFromProps(props: Readonly<InputStringProps>, state: InputStringState) {
-    if (!state.editing) {
-      return {
-        value: props.value
-      };
-    }
-    return {};
-  }
-
-  render() {
-    let tag;
-    let classes;
-
-    if(this.props.multi) {
-      tag = "textarea";
-      classes = [
-        "maputnik-string",
-        "maputnik-string--multi"
-      ];
-    }
-    else {
-      tag = "input";
-      classes = [
-        "maputnik-string"
-      ];
-    }
-
-    if(this.props.disabled) {
-      classes.push("maputnik-string--disabled");
-    }
-
-    return React.createElement(tag, {
-      "aria-label": this.props["aria-label"],
-      "data-wd-key": this.props["data-wd-key"],
-      spellCheck: Object.prototype.hasOwnProperty.call(this.props, "spellCheck") ? this.props.spellCheck : !(tag === "input"),
-      disabled: this.props.disabled,
-      className: classes.join(" "),
-      style: this.props.style,
-      value: this.state.value === undefined ? "" : this.state.value,
-      placeholder: this.props.default,
-      title: this.props.title,
-      onChange: (e: React.BaseSyntheticEvent<Event, HTMLInputElement, HTMLInputElement>) => {
-        this.setState({
-          editing: true,
-          value: e.target.value
-        }, () => {
-          if (this.props.onInput) this.props.onInput(this.state.value);
-        });
-      },
-      onBlur: () => {
-        if(this.state.value!==this.props.value) {
-          this.setState({editing: false});
-          if (this.props.onChange) this.props.onChange(this.state.value);
-        }
-      },
-      onKeyDown: (e) => {
-        if (e.keyCode === 13 && this.props.onChange) {
-          this.props.onChange(this.state.value);
-        }
-      },
-      required: this.props.required,
-    });
-  }
-}

src/components/InputUrl.tsx

@@ -1,4 +1,4 @@
-import React, { type JSX } from "react";
+import React, { type JSX, useState } from "react";
 import { InputString } from "./InputString";
 import { SmallError } from "./SmallError";
 import { Trans, type WithTranslation, withTranslation } from "react-i18next";
@@ -46,49 +46,30 @@ export type FieldUrlProps = {
 
 type InputUrlInternalProps = FieldUrlProps & WithTranslation;
 
-type InputUrlState = {
-  error?: ErrorType
+const InputUrlInternal: React.FC<InputUrlInternalProps> = ({onInput = () => {}, ...props}) => {
+  const [error, setError] = useState<ErrorType | undefined>(() => validate(props.value));
+
+  const handleInput = (url: string) => {
+    setError(validate(url));
+    onInput(url);
+  };
+
+  const handleChange = (url: string) => {
+    setError(validate(url));
+    props.onChange(url);
+  };
+
+  return (
+    <div>
+      <InputString
+        {...props}
+        onInput={handleInput}
+        onChange={handleChange}
+        aria-label={props["aria-label"]}
+      />
+      {errorTypeToJsx(error, props.t)}
+    </div>
+  );
 };
 
-class InputUrlInternal extends React.Component<InputUrlInternalProps, InputUrlState> {
-  static defaultProps = {
-    onInput: () => {},
-  };
-
-  constructor (props: InputUrlInternalProps) {
-    super(props);
-    this.state = {
-      error: validate(props.value),
-    };
-  }
-
-  onInput = (url: string) => {
-    this.setState({
-      error: validate(url),
-    });
-    if (this.props.onInput) this.props.onInput(url);
-  };
-
-  onChange = (url: string) => {
-    this.setState({
-      error: validate(url),
-    });
-    this.props.onChange(url);
-  };
-
-  render () {
-    return (
-      <div>
-        <InputString
-          {...this.props}
-          onInput={this.onInput}
-          onChange={this.onChange}
-          aria-label={this.props["aria-label"]}
-        />
-        {errorTypeToJsx(this.state.error, this.props.t)}
-      </div>
-    );
-  }
-}
-
 export const InputUrl = withTranslation()(InputUrlInternal);

src/components/LayerEditor.tsx

@@ -1,4 +1,4 @@
-import React, { type JSX } from "react";
+import React, { type JSX, useState } from "react";
 import { Wrapper, Button, Menu, MenuItem } from "react-aria-menubutton";
 import { Accordion } from "react-accessible-accordion";
 import { MdMoreVert } from "react-icons/md";
@@ -17,7 +17,9 @@ import { FieldMaxZoom } from "./FieldMaxZoom";
 import { FieldComment } from "./FieldComment";
 import { FieldSource } from "./FieldSource";
 import { FieldSourceLayer } from "./FieldSourceLayer";
-import { changeType, changeProperty } from "../libs/layer";
+// Aliased: the component defines its own changeProperty, which would otherwise
+// shadow this import (as a class method there was no collision).
+import { changeType, changeProperty as changeLayerProperty } from "../libs/layer";
 import { formatLayerId } from "../libs/format";
 import { type WithTranslation, withTranslation } from "react-i18next";
 import { type TFunction } from "i18next";
@@ -131,67 +133,56 @@ type LayerEditorInternalProps = {
   errors?: MappedError[]
 } & WithTranslation;
 
-type LayerEditorState = {
-  editorGroups: { [keys: string]: boolean }
-};
-
 /** Layer editor supporting multiple types of layers. */
-class LayerEditorInternal extends React.Component<LayerEditorInternalProps, LayerEditorState> {
-  static defaultProps = {
-    onLayerChanged: () => { },
-    onLayerIdChange: () => { },
-    onLayerDestroyed: () => { },
-  };
+const LayerEditorInternal: React.FC<LayerEditorInternalProps> = ({
+  onLayerChanged = () => { },
+  onLayerIdChange = () => { },
+  ...rest
+}) => {
+  const props = { onLayerChanged, onLayerIdChange, ...rest } as LayerEditorInternalProps;
 
-  constructor(props: LayerEditorInternalProps) {
-    super(props);
-
-    const editorGroups: { [keys: string]: boolean } = {};
-    for (const group of layoutGroups(this.props.layer.type, props.t)) {
-      editorGroups[group.title] = true;
+  const [editorGroups, setEditorGroups] = useState<{ [keys: string]: boolean }>(() => {
+    const groups: { [keys: string]: boolean } = {};
+    for (const group of layoutGroups(props.layer.type, props.t)) {
+      groups[group.title] = true;
     }
+    return groups;
+  });
 
-    this.state = { editorGroups };
+  // Replaces getDerivedStateFromProps: groups that appear after mount (because
+  // the layer type changed) start out expanded. Guarded so it only sets state
+  // when a group is genuinely new, otherwise this would loop every render.
+  const newGroups = getLayoutForType(props.layer.type, props.t)
+    .filter(group => !(group.title in editorGroups));
+  if (newGroups.length > 0) {
+    const additionalGroups = { ...editorGroups };
+    for (const group of newGroups) {
+      additionalGroups[group.title] = true;
+    }
+    setEditorGroups(additionalGroups);
   }
 
-  static getDerivedStateFromProps(props: Readonly<LayerEditorInternalProps>, state: LayerEditorState) {
-    const additionalGroups = { ...state.editorGroups };
-
-    for (const group of getLayoutForType(props.layer.type, props.t)) {
-      if (!(group.title in additionalGroups)) {
-        additionalGroups[group.title] = true;
-      }
-    }
-
-    return {
-      editorGroups: additionalGroups
-    };
-  }
-
-
-  changeProperty(group: keyof LayerSpecification | null, property: string, newValue: any) {
-    this.props.onLayerChanged(
-      this.props.layerIndex,
-      changeProperty(this.props.layer, group, property, newValue)
+  function changeProperty(group: keyof LayerSpecification | null, property: string, newValue: any) {
+    props.onLayerChanged(
+      props.layerIndex,
+      changeLayerProperty(props.layer, group, property, newValue)
     );
   }
 
-  onGroupToggle(groupTitle: string, active: boolean) {
+  function onGroupToggle(groupTitle: string, active: boolean) {
     const changedActiveGroups = {
-      ...this.state.editorGroups,
+      ...editorGroups,
       [groupTitle]: active,
     };
-    this.setState({
-      editorGroups: changedActiveGroups
-    });
+    setEditorGroups(changedActiveGroups);
   }
 
-  renderGroupType(type: string, fields?: string[]): JSX.Element {
+  function renderGroupType(type: string, fields?: string[]): JSX.Element {
     let comment = "";
-    if (this.props.layer.metadata) {
-      comment = (this.props.layer.metadata as any)["maputnik:comment"];
+    if (props.layer.metadata) {
+      comment = (props.layer.metadata as any)["maputnik:comment"];
     }
-    const { errors, layerIndex } = this.props;
+    const { errors, layerIndex } = props;
 
     const errorData: MappedLayerErrors = {};
     errors!.forEach(error => {
@@ -207,85 +198,85 @@ class LayerEditorInternal extends React.Component<LayerEditorInternalProps, Laye
     });
 
     let sourceLayerIds;
-    const layer = this.props.layer as Exclude<LayerSpecification, BackgroundLayerSpecification>;
-    if (Object.prototype.hasOwnProperty.call(this.props.sources, layer.source)) {
-      sourceLayerIds = this.props.sources[layer.source].layers;
+    const layer = props.layer as Exclude<LayerSpecification, BackgroundLayerSpecification>;
+    if (Object.prototype.hasOwnProperty.call(props.sources, layer.source)) {
+      sourceLayerIds = props.sources[layer.source].layers;
     }
 
     switch (type) {
       case "layer": return <div>
         <FieldId
-          value={this.props.layer.id}
+          value={props.layer.id}
           wdKey="layer-editor.layer-id"
           error={errorData.id}
-          onChange={newId => this.props.onLayerIdChange(this.props.layerIndex, this.props.layer.id, newId)}
+          onChange={newId => props.onLayerIdChange(props.layerIndex, props.layer.id, newId)}
         />
         <FieldType
           disabled={true}
           error={errorData.type}
-          value={this.props.layer.type}
-          onChange={newType => this.props.onLayerChanged(
-            this.props.layerIndex,
-            changeType(this.props.layer, newType)
+          value={props.layer.type}
+          onChange={newType => props.onLayerChanged(
+            props.layerIndex,
+            changeType(props.layer, newType)
           )}
         />
-        {this.props.layer.type !== "background" && <FieldSource
+        {props.layer.type !== "background" && <FieldSource
           wdKey="layer-editor.layer-source"
           error={errorData.source}
-          sourceIds={Object.keys(this.props.sources!)}
-          value={this.props.layer.source}
-          onChange={v => this.changeProperty(null, "source", v)}
+          sourceIds={Object.keys(props.sources!)}
+          value={props.layer.source}
+          onChange={v => changeProperty(null, "source", v)}
         />
         }
-        {!NON_SOURCE_LAYERS.includes(this.props.layer.type) &&
+        {!NON_SOURCE_LAYERS.includes(props.layer.type) &&
           <FieldSourceLayer
             error={errorData["source-layer"]}
             sourceLayerIds={sourceLayerIds}
-            value={(this.props.layer as any)["source-layer"]}
-            onChange={v => this.changeProperty(null, "source-layer", v)}
+            value={(props.layer as any)["source-layer"]}
+            onChange={v => changeProperty(null, "source-layer", v)}
           />
         }
         <FieldMinZoom
           error={errorData.minzoom}
-          value={this.props.layer.minzoom}
-          onChange={v => this.changeProperty(null, "minzoom", v)}
+          value={props.layer.minzoom}
+          onChange={v => changeProperty(null, "minzoom", v)}
         />
         <FieldMaxZoom
           error={errorData.maxzoom}
-          value={this.props.layer.maxzoom}
-          onChange={v => this.changeProperty(null, "maxzoom", v)}
+          value={props.layer.maxzoom}
+          onChange={v => changeProperty(null, "maxzoom", v)}
         />
         <FieldComment
           error={errorData.comment}
           value={comment}
-          onChange={v => this.changeProperty("metadata", "maputnik:comment", v == "" ? undefined : v)}
+          onChange={v => changeProperty("metadata", "maputnik:comment", v == "" ? undefined : v)}
         />
       </div>;
       case "filter": return <div>
         <div className="maputnik-filter-editor-wrapper">
           <FilterEditor
             errors={errorData}
-            filter={(this.props.layer as any).filter}
-            properties={this.props.vectorLayers[(this.props.layer as any)["source-layer"]]}
-            onChange={f => this.changeProperty(null, "filter", f)}
+            filter={(props.layer as any).filter}
+            properties={props.vectorLayers[(props.layer as any)["source-layer"]]}
+            onChange={f => changeProperty(null, "filter", f)}
           />
         </div>
       </div>;
       case "properties":
         return <PropertyGroup
           errors={errorData}
-          layer={this.props.layer}
+          layer={props.layer}
           groupFields={fields!}
-          spec={this.props.spec}
-          onChange={this.changeProperty.bind(this)}
+          spec={props.spec}
+          onChange={changeProperty.bind(null)}
         />;
       case "jsoneditor":
         return <FieldJson
           lintType="layer"
-          value={this.props.layer}
+          value={props.layer}
           onChange={(layer: LayerSpecification) => {
-            this.props.onLayerChanged(
-              this.props.layerIndex,
+            props.onLayerChanged(
+              props.layerIndex,
               layer
             );
           }}
@@ -294,130 +285,128 @@ class LayerEditorInternal extends React.Component<LayerEditorInternalProps, Laye
     }
   }
 
-  moveLayer(offset: number) {
-    this.props.onMoveLayer({
-      oldIndex: this.props.layerIndex,
-      newIndex: this.props.layerIndex + offset
+  function moveLayer(offset: number) {
+    props.onMoveLayer({
+      oldIndex: props.layerIndex,
+      newIndex: props.layerIndex + offset
     });
   }
 
-  render() {
-    const t = this.props.t;
+  const t = props.t;
 
-    const groupIds: string[] = [];
-    const layerType = this.props.layer.type;
-    const groups = layoutGroups(layerType, t).filter(group => {
-      return !(layerType === "background" && group.type === "source");
-    }).map(group => {
-      const groupId = group.id;
-      groupIds.push(groupId);
-      return <LayerEditorGroup
-        data-wd-key={group.title}
-        id={groupId}
-        key={groupId}
-        title={group.title}
-        isActive={this.state.editorGroups[group.title]}
-        onActiveToggle={this.onGroupToggle.bind(this, group.title)}
-      >
-        {this.renderGroupType(group.type, group.fields)}
-      </LayerEditorGroup>;
-    });
+  const groupIds: string[] = [];
+  const layerType = props.layer.type;
+  const groups = layoutGroups(layerType, t).filter(group => {
+    return !(layerType === "background" && group.type === "source");
+  }).map(group => {
+    const groupId = group.id;
+    groupIds.push(groupId);
+    return <LayerEditorGroup
+      data-wd-key={group.title}
+      id={groupId}
+      key={groupId}
+      title={group.title}
+      isActive={editorGroups[group.title]}
+      onActiveToggle={onGroupToggle.bind(null, group.title)}
+    >
+      {renderGroupType(group.type, group.fields)}
+    </LayerEditorGroup>;
+  });
 
-    const layout = this.props.layer.layout || {};
+  const layout = props.layer.layout || {};
 
-    const items: {
-      [key: string]: {
-        text: string,
-        handler: () => void,
-        disabled?: boolean,
-        wdKey?: string
-      }
-    } = {
-      delete: {
-        text: t("Delete"),
-        handler: () => this.props.onLayerDestroy(this.props.layerIndex),
-        wdKey: "menu-delete-layer"
-      },
-      duplicate: {
-        text: t("Duplicate"),
-        handler: () => this.props.onLayerCopy(this.props.layerIndex),
-        wdKey: "menu-duplicate-layer"
-      },
-      hide: {
-        text: (layout.visibility === "none") ? t("Show") : t("Hide"),
-        handler: () => this.props.onLayerVisibilityToggle(this.props.layerIndex),
-        wdKey: "menu-hide-layer"
-      },
-      moveLayerUp: {
-        text: t("Move layer up"),
-        disabled: this.props.isFirstLayer,
-        handler: () => this.moveLayer(-1),
-        wdKey: "menu-move-layer-up"
-      },
-      moveLayerDown: {
-        text: t("Move layer down"),
-        disabled: this.props.isLastLayer,
-        handler: () => this.moveLayer(+1),
-        wdKey: "menu-move-layer-down"
-      }
-    };
-
-    function handleSelection(id: string, event: React.SyntheticEvent) {
-      event.stopPropagation();
-      items[id].handler();
+  const items: {
+    [key: string]: {
+      text: string,
+      handler: () => void,
+      disabled?: boolean,
+      wdKey?: string
     }
+  } = {
+    delete: {
+      text: t("Delete"),
+      handler: () => props.onLayerDestroy(props.layerIndex),
+      wdKey: "menu-delete-layer"
+    },
+    duplicate: {
+      text: t("Duplicate"),
+      handler: () => props.onLayerCopy(props.layerIndex),
+      wdKey: "menu-duplicate-layer"
+    },
+    hide: {
+      text: (layout.visibility === "none") ? t("Show") : t("Hide"),
+      handler: () => props.onLayerVisibilityToggle(props.layerIndex),
+      wdKey: "menu-hide-layer"
+    },
+    moveLayerUp: {
+      text: t("Move layer up"),
+      disabled: props.isFirstLayer,
+      handler: () => moveLayer(-1),
+      wdKey: "menu-move-layer-up"
+    },
+    moveLayerDown: {
+      text: t("Move layer down"),
+      disabled: props.isLastLayer,
+      handler: () => moveLayer(+1),
+      wdKey: "menu-move-layer-down"
+    }
+  };
 
-    return <IconContext.Provider value={{ size: "14px", color: "#8e8e8e" }}>
-      <section className="maputnik-layer-editor"
-        role="main"
-        aria-label={t("Layer editor")}
-        data-wd-key="layer-editor"
-      >
-        <header data-wd-key="layer-editor.header">
-          <div className="layer-header">
-            <h2 className="layer-header__title">
-              {t("Layer")}: {formatLayerId(this.props.layer.id)}
-            </h2>
-            <div className="layer-header__info">
-              <Wrapper
-                className='more-menu'
-                onSelection={(id, event) => handleSelection(id as string, event)}
-                closeOnSelection={false}
-              >
-                <Button
-                  id="skip-target-layer-editor"
-                  data-wd-key="skip-target-layer-editor"
-                  className='more-menu__button'
-                  title={"Layer options"}>
-                  <MdMoreVert className="more-menu__button__svg" />
-                </Button>
-                <Menu>
-                  <ul className="more-menu__menu">
-                    {Object.keys(items).map((id) => {
-                      const item = items[id];
-                      return <li key={id}>
-                        <MenuItem value={id} className='more-menu__menu__item' data-wd-key={item.wdKey}>
-                          {item.text}
-                        </MenuItem>
-                      </li>;
-                    })}
-                  </ul>
-                </Menu>
-              </Wrapper>
-            </div>
-          </div>
-
-        </header>
-        <Accordion
-          allowMultipleExpanded={true}
-          allowZeroExpanded={true}
-          preExpanded={groupIds}
-        >
-          {groups}
-        </Accordion>
-      </section>
-    </IconContext.Provider>;
+  function handleSelection(id: string, event: React.SyntheticEvent) {
+    event.stopPropagation();
+    items[id].handler();
   }
-}
+
+  return <IconContext.Provider value={{ size: "14px", color: "#8e8e8e" }}>
+    <section className="maputnik-layer-editor"
+      role="main"
+      aria-label={t("Layer editor")}
+      data-wd-key="layer-editor"
+    >
+      <header data-wd-key="layer-editor.header">
+        <div className="layer-header">
+          <h2 className="layer-header__title">
+            {t("Layer")}: {formatLayerId(props.layer.id)}
+          </h2>
+          <div className="layer-header__info">
+            <Wrapper
+              className='more-menu'
+              onSelection={(id, event) => handleSelection(id as string, event)}
+              closeOnSelection={false}
+            >
+              <Button
+                id="skip-target-layer-editor"
+                data-wd-key="skip-target-layer-editor"
+                className='more-menu__button'
+                title={"Layer options"}>
+                <MdMoreVert className="more-menu__button__svg" />
+              </Button>
+              <Menu>
+                <ul className="more-menu__menu">
+                  {Object.keys(items).map((id) => {
+                    const item = items[id];
+                    return <li key={id}>
+                      <MenuItem value={id} className='more-menu__menu__item' data-wd-key={item.wdKey}>
+                        {item.text}
+                      </MenuItem>
+                    </li>;
+                  })}
+                </ul>
+              </Menu>
+            </Wrapper>
+          </div>
+        </div>
+
+      </header>
+      <Accordion
+        allowMultipleExpanded={true}
+        allowZeroExpanded={true}
+        preExpanded={groupIds}
+      >
+        {groups}
+      </Accordion>
+    </section>
+  </IconContext.Provider>;
+};
 
 export const LayerEditor = withTranslation()(LayerEditorInternal);

src/components/LayerEditorGroup.tsx

@@ -18,22 +18,20 @@ type LayerEditorGroupProps = {
 };
 
 
-export class LayerEditorGroup extends React.Component<LayerEditorGroupProps> {
-  render() {
-    return <AccordionItem uuid={this.props.id}>
-      <AccordionItemHeading className="maputnik-layer-editor-group"
-        data-wd-key={"layer-editor-group:"+this.props["data-wd-key"]}
-        onClick={_e => this.props.onActiveToggle(!this.props.isActive)}
-      >
-        <AccordionItemButton className="maputnik-layer-editor-group__button">
-          <span style={{flexGrow: 1, alignContent: "center"}}>{this.props.title}</span>
-          <MdArrowDropUp size={"2em"} className="maputnik-layer-editor-group__button__icon maputnik-layer-editor-group__button__icon--up"></MdArrowDropUp>
-          <MdArrowDropDown size={"2em"} className="maputnik-layer-editor-group__button__icon maputnik-layer-editor-group__button__icon--down"></MdArrowDropDown>
-        </AccordionItemButton>
-      </AccordionItemHeading>
-      <AccordionItemPanel>
-        {this.props.children}
-      </AccordionItemPanel>
-    </AccordionItem>;
-  }
-}
+export const LayerEditorGroup: React.FC<LayerEditorGroupProps> = (props) => {
+  return <AccordionItem uuid={props.id}>
+    <AccordionItemHeading className="maputnik-layer-editor-group"
+      data-wd-key={"layer-editor-group:"+props["data-wd-key"]}
+      onClick={_e => props.onActiveToggle(!props.isActive)}
+    >
+      <AccordionItemButton className="maputnik-layer-editor-group__button">
+        <span style={{flexGrow: 1, alignContent: "center"}}>{props.title}</span>
+        <MdArrowDropUp size={"2em"} className="maputnik-layer-editor-group__button__icon maputnik-layer-editor-group__button__icon--up"></MdArrowDropUp>
+        <MdArrowDropDown size={"2em"} className="maputnik-layer-editor-group__button__icon maputnik-layer-editor-group__button__icon--down"></MdArrowDropDown>
+      </AccordionItemButton>
+    </AccordionItemHeading>
+    <AccordionItemPanel>
+      {props.children}
+    </AccordionItemPanel>
+  </AccordionItem>;
+};

src/components/LayerList.tsx

@@ -1,4 +1,4 @@
-import React, {type JSX} from "react";
+import React, {type JSX, useEffect, useRef, useState} from "react";
 import classnames from "classnames";
 import lodash from "lodash";
 import {
@@ -37,62 +37,98 @@ type LayerListContainerProps = {
 };
 type LayerListContainerInternalProps = LayerListContainerProps & WithTranslation;
 
-type LayerListContainerState = {
-  collapsedGroups: {[ket: string]: boolean}
-  areAllGroupsExpanded: boolean
-  keys: {[key: string]: number}
-  isOpen: {[key: string]: boolean}
-};
+const noopLayerSelect = () => {};
+
+// Replaces the previous `shouldComponentUpdate`. Note the inversion: this
+// returns true when the props are EQUAL (i.e. no re-render is needed), whereas
+// `shouldComponentUpdate` returned true when a re-render WAS needed.
+function arePropsEqual(prevProps: LayerListContainerInternalProps, nextProps: LayerListContainerInternalProps) {
+  // This component tree only requires id and visibility from the layers
+  // objects
+  function getRequiredProps(layer: LayerSpecification) {
+    const out: {id: string, layout?: { visibility: any}} = {
+      id: layer.id,
+    };
+
+    if (layer.layout) {
+      out.layout = {
+        visibility: layer.layout.visibility
+      };
+    }
+    return out;
+  }
+  const layersEqual = lodash.isEqual(
+    nextProps.layers.map(getRequiredProps),
+    prevProps.layers.map(getRequiredProps),
+  );
+
+  function withoutLayers(props: LayerListContainerInternalProps) {
+    const out = {
+      ...props
+    } as LayerListContainerInternalProps & { layers?: any };
+    delete out["layers"];
+    return out;
+  }
+
+  // Compare the props without layers because we've already compared them
+  // efficiently above.
+  const propsEqual = lodash.isEqual(
+    withoutLayers(prevProps),
+    withoutLayers(nextProps)
+  );
+
+  return layersEqual && propsEqual;
+}
 
 // List of collapsible layer editors
-class LayerListContainerInternal extends React.Component<LayerListContainerInternalProps, LayerListContainerState> {
-  static defaultProps = {
-    onLayerSelect: () => {},
-  };
-  selectedItemRef: React.RefObject<any>;
-  scrollContainerRef: React.RefObject<HTMLElement | null>;
+function LayerListContainerInternal({
+  layers: propsLayers,
+  selectedLayerIndex,
+  onLayersChange,
+  onLayerSelect = noopLayerSelect,
+  onLayerDestroy,
+  onLayerCopy,
+  onLayerVisibilityToggle,
+  sources,
+  errors,
+  t,
+}: LayerListContainerInternalProps) {
+  const selectedItemRef = useRef<any>(null);
+  const scrollContainerRef = useRef<HTMLElement | null>(null);
+  const hasMountedRef = useRef(false);
 
-  constructor(props: LayerListContainerInternalProps) {
-    super(props);
-    this.selectedItemRef = React.createRef();
-    this.scrollContainerRef = React.createRef();
-    this.state = {
-      collapsedGroups: {},
-      areAllGroupsExpanded: false,
-      keys: {
-        add: +generateUniqueId(),
-      },
-      isOpen: {
-        add: false,
-      }
-    };
+  const [collapsedGroups, setCollapsedGroups] = useState<{[key: string]: boolean}>({});
+  const [areAllGroupsExpanded, setAreAllGroupsExpanded] = useState(false);
+  const [keys, setKeys] = useState<{[key: string]: number}>(() => ({
+    add: +generateUniqueId(),
+  }));
+  const [isOpen, setIsOpen] = useState<{[key: string]: boolean}>({
+    add: false,
+  });
+
+  function toggleModal(modalName: string) {
+    setKeys(prevKeys => ({
+      ...prevKeys,
+      [modalName]: +generateUniqueId(),
+    }));
+    setIsOpen(prevIsOpen => ({
+      ...prevIsOpen,
+      [modalName]: !prevIsOpen[modalName]
+    }));
   }
 
-  toggleModal(modalName: string) {
-    this.setState({
-      keys: {
-        ...this.state.keys,
-        [modalName]: +generateUniqueId(),
-      },
-      isOpen: {
-        ...this.state.isOpen,
-        [modalName]: !this.state.isOpen[modalName]
-      }
-    });
-  }
-
-  toggleLayers = () => {
+  const toggleLayers = () => {
     let idx = 0;
 
     const newGroups: {[key:string]: boolean} = {};
 
-    this.groupedLayers().forEach(layers => {
+    groupedLayers().forEach(layers => {
       const groupPrefix = layerPrefix(layers[0].id);
       const lookupKey = [groupPrefix, idx].join("-");
 
 
       if (layers.length > 1) {
-        newGroups[lookupKey] = this.state.areAllGroupsExpanded;
+        newGroups[lookupKey] = areAllGroupsExpanded;
       }
 
       layers.forEach((_layer) => {
@@ -100,19 +136,17 @@ class LayerListContainerInternal extends React.Component<LayerListContainerInter
       });
     });
 
-    this.setState({
-      collapsedGroups: newGroups,
-      areAllGroupsExpanded: !this.state.areAllGroupsExpanded
-    });
+    setCollapsedGroups(newGroups);
+    setAreAllGroupsExpanded(!areAllGroupsExpanded);
   };
 
-  groupedLayers(): (LayerSpecification & {key: string})[][] {
+  function groupedLayers(): (LayerSpecification & {key: string})[][] {
     const groups = [];
     const layerIdCount = new Map();
 
-    for (let i = 0; i < this.props.layers.length; i++) {
-      const origLayer = this.props.layers[i];
-      const previousLayer = this.props.layers[i-1];
+    for (let i = 0; i < propsLayers.length; i++) {
+      const origLayer = propsLayers[i];
+      const previousLayer = propsLayers[i-1];
       layerIdCount.set(origLayer.id,
         layerIdCount.has(origLayer.id) ? layerIdCount.get(origLayer.id) + 1 : 0
       );
@@ -130,207 +164,162 @@ class LayerListContainerInternal extends React.Component<LayerListContainerInter
     return groups;
   }
 
-  toggleLayerGroup(groupPrefix: string, idx: number) {
+  function toggleLayerGroup(groupPrefix: string, idx: number) {
     const lookupKey = [groupPrefix, idx].join("-");
-    const newGroups = { ...this.state.collapsedGroups };
-    if(lookupKey in this.state.collapsedGroups) {
-      newGroups[lookupKey] = !this.state.collapsedGroups[lookupKey];
-    } else {
-      newGroups[lookupKey] = false;
-    }
-    this.setState({
-      collapsedGroups: newGroups
+    setCollapsedGroups(prevCollapsedGroups => {
+      const newGroups = { ...prevCollapsedGroups };
+      if(lookupKey in prevCollapsedGroups) {
+        newGroups[lookupKey] = !prevCollapsedGroups[lookupKey];
+      } else {
+        newGroups[lookupKey] = false;
+      }
+      return newGroups;
     });
   }
 
-  isCollapsed(groupPrefix: string, idx: number) {
-    const collapsed = this.state.collapsedGroups[[groupPrefix, idx].join("-")];
+  function isCollapsed(groupPrefix: string, idx: number) {
+    const collapsed = collapsedGroups[[groupPrefix, idx].join("-")];
     return collapsed === undefined ? true : collapsed;
   }
 
-  shouldComponentUpdate (nextProps: LayerListContainerProps, nextState: LayerListContainerState) {
-    // Always update on state change
-    if (this.state !== nextState) {
-      return true;
+  useEffect(() => {
+    // `componentDidUpdate` did not run on mount, so skip the first run here too.
+    if (!hasMountedRef.current) {
+      hasMountedRef.current = true;
+      return;
     }
-
-    // This component tree only requires id and visibility from the layers
-    // objects
-    function getRequiredProps(layer: LayerSpecification) {
-      const out: {id: string, layout?: { visibility: any}} = {
-        id: layer.id,
+    const selectedItemNode = selectedItemRef.current;
+    if (selectedItemNode && selectedItemNode.node) {
+      const target = selectedItemNode.node;
+      const options = {
+        root: scrollContainerRef.current,
+        threshold: 1.0
       };
-
-      if (layer.layout) {
-        out.layout = {
-          visibility: layer.layout.visibility
-        };
-      }
-      return out;
-    }
-    const layersEqual = lodash.isEqual(
-      nextProps.layers.map(getRequiredProps),
-      this.props.layers.map(getRequiredProps),
-    );
-
-    function withoutLayers(props: LayerListContainerProps) {
-      const out = {
-        ...props
-      } as LayerListContainerProps & { layers?: any };
-      delete out["layers"];
-      return out;
-    }
-
-    // Compare the props without layers because we've already compared them
-    // efficiently above.
-    const propsEqual = lodash.isEqual(
-      withoutLayers(this.props),
-      withoutLayers(nextProps)
-    );
-
-    const propsChanged = !(layersEqual && propsEqual);
-    return propsChanged;
-  }
-
-  componentDidUpdate (prevProps: LayerListContainerProps) {
-    if (prevProps.selectedLayerIndex !== this.props.selectedLayerIndex) {
-      const selectedItemNode = this.selectedItemRef.current;
-      if (selectedItemNode && selectedItemNode.node) {
-        const target = selectedItemNode.node;
-        const options = {
-          root: this.scrollContainerRef.current,
-          threshold: 1.0
-        };
-        const observer = new IntersectionObserver(entries => {
-          observer.unobserve(target);
-          if (entries.length > 0 && entries[0].intersectionRatio < 1) {
-            target.scrollIntoView();
-          }
-        }, options);
-
-        observer.observe(target);
-      }
-    }
-  }
-
-  render() {
-
-    const listItems: JSX.Element[] = [];
-    let idx = 0;
-    const layersByGroup = this.groupedLayers();
-    layersByGroup.forEach(layers => {
-      const groupPrefix = layerPrefix(layers[0].id);
-      if(layers.length > 1) {
-        const grp = <LayerListGroup
-          data-wd-key={[groupPrefix, idx].join("-")}
-          aria-controls={layers.map(l => l.key).join(" ")}
-          key={`group-${groupPrefix}-${idx}`}
-          title={groupPrefix}
-          isActive={!this.isCollapsed(groupPrefix, idx) || idx === this.props.selectedLayerIndex}
-          onActiveToggle={this.toggleLayerGroup.bind(this, groupPrefix, idx)}
-        />;
-        listItems.push(grp);
-      }
-
-      layers.forEach((layer, idxInGroup) => {
-        const groupIdx = findClosestCommonPrefix(this.props.layers, idx);
-
-        const layerError = this.props.errors.find(error => {
-          return (
-            error.parsed &&
-            error.parsed.type === "layer" &&
-            error.parsed.data.index == idx
-          );
-        });
-
-        const additionalProps: {ref?: React.RefObject<any>} = {};
-        if (idx === this.props.selectedLayerIndex) {
-          additionalProps.ref = this.selectedItemRef;
+      const observer = new IntersectionObserver(entries => {
+        observer.unobserve(target);
+        if (entries.length > 0 && entries[0].intersectionRatio < 1) {
+          target.scrollIntoView();
         }
+      }, options);
 
-        const listItem = <LayerListItem
-          className={classnames({
-            "maputnik-layer-list-item-collapsed": layers.length > 1 && this.isCollapsed(groupPrefix, groupIdx) && idx !== this.props.selectedLayerIndex,
-            "maputnik-layer-list-item-group-last": idxInGroup == layers.length - 1 && layers.length > 1,
-            "maputnik-layer-list-item--error": !!layerError
-          })}
-          key={layer.key}
-          id={layer.key}
-          layerId={layer.id}
-          layerIndex={idx}
-          layerType={layer.type}
-          visibility={(layer.layout || {}).visibility}
-          isSelected={idx === this.props.selectedLayerIndex}
-          onLayerSelect={this.props.onLayerSelect}
-          onLayerDestroy={this.props.onLayerDestroy?.bind(this)}
-          onLayerCopy={this.props.onLayerCopy.bind(this)}
-          onLayerVisibilityToggle={this.props.onLayerVisibilityToggle.bind(this)}
-          {...additionalProps}
-        />;
-        listItems.push(listItem);
-        idx += 1;
+      observer.observe(target);
+    }
+  }, [selectedLayerIndex]);
+
+  const listItems: JSX.Element[] = [];
+  let idx = 0;
+  const layersByGroup = groupedLayers();
+  layersByGroup.forEach(layers => {
+    const groupPrefix = layerPrefix(layers[0].id);
+    if(layers.length > 1) {
+      const currentIdx = idx;
+      const grp = <LayerListGroup
+        data-wd-key={[groupPrefix, idx].join("-")}
+        aria-controls={layers.map(l => l.key).join(" ")}
+        key={`group-${groupPrefix}-${idx}`}
+        title={groupPrefix}
+        isActive={!isCollapsed(groupPrefix, idx) || idx === selectedLayerIndex}
+        onActiveToggle={() => toggleLayerGroup(groupPrefix, currentIdx)}
+      />;
+      listItems.push(grp);
+    }
+
+    layers.forEach((layer, idxInGroup) => {
+      const groupIdx = findClosestCommonPrefix(propsLayers, idx);
+
+      const layerError = errors.find(error => {
+        return (
+          error.parsed &&
+          error.parsed.type === "layer" &&
+          error.parsed.data.index == idx
+        );
       });
+
+      const additionalProps: {ref?: React.RefObject<any>} = {};
+      if (idx === selectedLayerIndex) {
+        additionalProps.ref = selectedItemRef;
+      }
+
+      const listItem = <LayerListItem
+        className={classnames({
+          "maputnik-layer-list-item-collapsed": layers.length > 1 && isCollapsed(groupPrefix, groupIdx) && idx !== selectedLayerIndex,
+          "maputnik-layer-list-item-group-last": idxInGroup == layers.length - 1 && layers.length > 1,
+          "maputnik-layer-list-item--error": !!layerError
+        })}
+        key={layer.key}
+        id={layer.key}
+        layerId={layer.id}
+        layerIndex={idx}
+        layerType={layer.type}
+        visibility={(layer.layout || {}).visibility}
+        isSelected={idx === selectedLayerIndex}
+        onLayerSelect={onLayerSelect}
+        onLayerDestroy={onLayerDestroy}
+        onLayerCopy={onLayerCopy}
+        onLayerVisibilityToggle={onLayerVisibilityToggle}
+        {...additionalProps}
+      />;
+      listItems.push(listItem);
+      idx += 1;
     });
+  });
 
-    const t = this.props.t;
-
-    return <section
-      className="maputnik-layer-list"
-      data-wd-key="layer-list"
-      role="complementary"
-      aria-label={t("Layers list")}
-      ref={this.scrollContainerRef}
-    >
-      <ModalAdd
-        key={this.state.keys.add}
-        layers={this.props.layers}
-        sources={this.props.sources}
-        isOpen={this.state.isOpen.add}
-        onOpenToggle={this.toggleModal.bind(this, "add")}
-        onLayersChange={this.props.onLayersChange}
-      />
-      <header className="maputnik-layer-list-header" data-wd-key="layer-list.header">
-        <span className="maputnik-layer-list-header-title">{t("Layers")}</span>
-        <span className="maputnik-space" />
-        <div className="maputnik-default-property">
-          <div className="maputnik-multibutton">
-            <button
-              id="skip-target-layer-list"
-              data-wd-key="skip-target-layer-list"
-              onClick={this.toggleLayers}
-              className="maputnik-button">
-              {this.state.areAllGroupsExpanded === true ?
-                t("Collapse")
-                :
-                t("Expand")
-              }
-            </button>
-          </div>
+  return <section
+    className="maputnik-layer-list"
+    data-wd-key="layer-list"
+    role="complementary"
+    aria-label={t("Layers list")}
+    ref={scrollContainerRef}
+  >
+    <ModalAdd
+      key={keys.add}
+      layers={propsLayers}
+      sources={sources}
+      isOpen={isOpen.add}
+      onOpenToggle={() => toggleModal("add")}
+      onLayersChange={onLayersChange}
+    />
+    <header className="maputnik-layer-list-header" data-wd-key="layer-list.header">
+      <span className="maputnik-layer-list-header-title">{t("Layers")}</span>
+      <span className="maputnik-space" />
+      <div className="maputnik-default-property">
+        <div className="maputnik-multibutton">
+          <button
+            id="skip-target-layer-list"
+            data-wd-key="skip-target-layer-list"
+            onClick={toggleLayers}
+            className="maputnik-button">
+            {areAllGroupsExpanded === true ?
+              t("Collapse")
+              :
+              t("Expand")
+            }
+          </button>
         </div>
-        <div className="maputnik-default-property">
-          <div className="maputnik-multibutton">
-            <button
-              onClick={this.toggleModal.bind(this, "add")}
-              data-wd-key="layer-list:add-layer"
-              className="maputnik-button maputnik-button-selected">
-              {t("Add Layer")}
-            </button>
-          </div>
-        </div>
-      </header>
-      <div
-        role="navigation"
-        aria-label={t("Layers list")}
-      >
-        <ul className="maputnik-layer-list-container">
-          {listItems}
-        </ul>
       </div>
-    </section>;
-  }
+      <div className="maputnik-default-property">
+        <div className="maputnik-multibutton">
+          <button
+            onClick={() => toggleModal("add")}
+            data-wd-key="layer-list:add-layer"
+            className="maputnik-button maputnik-button-selected">
+            {t("Add Layer")}
+          </button>
+        </div>
+      </div>
+    </header>
+    <div
+      role="navigation"
+      aria-label={t("Layers list")}
+    >
+      <ul className="maputnik-layer-list-container">
+        {listItems}
+      </ul>
+    </div>
+  </section>;
 }
 
-const LayerListContainer = withTranslation()(LayerListContainerInternal);
+const LayerListContainer = withTranslation()(React.memo(LayerListContainerInternal, arePropsEqual));
 
 type LayerListProps = LayerListContainerProps & {
   onMoveLayer: OnMoveLayerCallback

src/components/LayerListGroup.tsx

@@ -9,26 +9,24 @@ type LayerListGroupProps = {
   "aria-controls"?: string
 };
 
-export class LayerListGroup extends React.Component<LayerListGroupProps> {
-  render() {
-    return <li className="maputnik-layer-list-group">
-      <div className="maputnik-layer-list-group-header"
-        data-wd-key={"layer-list-group:"+this.props["data-wd-key"]}
-        onClick={_e => this.props.onActiveToggle(!this.props.isActive)}
+export const LayerListGroup: React.FC<LayerListGroupProps> = (props) => {
+  return <li className="maputnik-layer-list-group">
+    <div className="maputnik-layer-list-group-header"
+      data-wd-key={"layer-list-group:"+props["data-wd-key"]}
+      onClick={_e => props.onActiveToggle(!props.isActive)}
+    >
+      <button
+        className="maputnik-layer-list-group-title"
+        aria-controls={props["aria-controls"]}
+        aria-expanded={props.isActive}
       >
-        <button
-          className="maputnik-layer-list-group-title"
-          aria-controls={this.props["aria-controls"]}
-          aria-expanded={this.props.isActive}
-        >
-          {this.props.title}
-        </button>
-        <span className="maputnik-space" />
-        <Collapser
-          style={{ height: 14, width: 14 }}
-          isCollapsed={this.props.isActive}
-        />
-      </div>
-    </li>;
-  }
-}
+        {props.title}
+      </button>
+      <span className="maputnik-space" />
+      <Collapser
+        style={{ height: 14, width: 14 }}
+        isCollapsed={props.isActive}
+      />
+    </div>
+  </li>;
+};

src/components/LayerListItem.tsx

@@ -38,9 +38,9 @@ type IconActionProps = {
   classBlockModifier?: string
 };
 
-class IconAction extends React.Component<IconActionProps> {
-  renderIcon() {
-    switch (this.props.action) {
+const IconAction: React.FC<IconActionProps> = (props) => {
+  function renderIcon() {
+    switch (props.action) {
       case "duplicate": return <MdContentCopy />;
       case "show": return <MdVisibility />;
       case "hide": return <MdVisibilityOff />;
@@ -48,30 +48,28 @@ class IconAction extends React.Component<IconActionProps> {
     }
   }
 
-  render() {
-    const { classBlockName, classBlockModifier } = this.props;
+  const { classBlockName, classBlockModifier } = props;
 
-    let classAdditions = "";
-    if (classBlockName) {
-      classAdditions = `maputnik-layer-list-icon-action__${classBlockName}`;
+  let classAdditions = "";
+  if (classBlockName) {
+    classAdditions = `maputnik-layer-list-icon-action__${classBlockName}`;
 
-      if (classBlockModifier) {
-        classAdditions += ` maputnik-layer-list-icon-action__${classBlockName}--${classBlockModifier}`;
-      }
+    if (classBlockModifier) {
+      classAdditions += ` maputnik-layer-list-icon-action__${classBlockName}--${classBlockModifier}`;
     }
-
-    return <button
-      tabIndex={-1}
-      title={this.props.action}
-      className={`maputnik-layer-list-icon-action ${classAdditions}`}
-      data-wd-key={this.props.wdKey}
-      onClick={this.props.onClick}
-      aria-hidden="true"
-    >
-      {this.renderIcon()}
-    </button>;
   }
-}
+
+  return <button
+    tabIndex={-1}
+    title={props.action}
+    className={`maputnik-layer-list-icon-action ${classAdditions}`}
+    data-wd-key={props.wdKey}
+    onClick={props.onClick}
+    aria-hidden="true"
+  >
+    {renderIcon()}
+  </button>;
+};
 
 type LayerListItemProps = {
   id?: string

src/components/MapMaplibreGl.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, {useCallback, useEffect, useReducer, useRef} from "react";
 import {createRoot} from "react-dom/client";
 import MapLibreGl, {type LayerSpecification, type LngLat, type Map, type MapOptions, type SourceSpecification, type StyleSpecification} from "maplibre-gl";
 import MaplibreInspect from "@maplibre/maplibre-gl-inspect";
@@ -71,199 +71,65 @@ type MapMaplibreGlInternalProps = {
   onChange(value: {center: LngLat, zoom: number, _from: "map" | "app"}): unknown
 } & WithTranslation;
 
-type MapMaplibreGlState = {
-  map: Map | null;
-  inspect: MaplibreInspect | null;
-  geocoder: MaplibreGeocoder | null;
-  zoomControl: ZoomControl | null;
-  zoom?: number;
-};
-
-class MapMaplibreGlInternal extends React.Component<MapMaplibreGlInternalProps, MapMaplibreGlState> {
-  static defaultProps = {
-    onMapLoaded: () => {},
-    onDataChange: () => {},
-    onLayerSelect: () => {},
-    onChange: () => {},
-    options: {} as MapOptions,
-  };
-  container: HTMLDivElement | null = null;
-
-  constructor(props: MapMaplibreGlInternalProps) {
-    super(props);
-    this.state = {
-      map: null,
-      inspect: null,
-      geocoder: null,
-      zoomControl: null,
-    };
-    i18next.on("languageChanged", () => {
-      this.forceUpdate();
-    });
+/**
+ * Replacement for the previous `shouldComponentUpdate`. `React.memo` expects the
+ * inverse: `true` means "props are equal, skip the render", whereas
+ * `shouldComponentUpdate` returned `true` when it *should* re-render.
+ * As before, if the props cannot be serialized we treat them as equal and skip
+ * the render ("no biggie, carry on").
+ */
+function arePropsEqual(prevProps: MapMaplibreGlInternalProps, nextProps: MapMaplibreGlInternalProps) {
+  let should = false;
+  try {
+    should = JSON.stringify(prevProps) !== JSON.stringify(nextProps);
+  } catch(_e) {
+    // no biggie, carry on
   }
+  return !should;
+}
 
+const MapMaplibreGlInternal = ({
+  onDataChange = () => {},
+  onLayerSelect = () => {},
+  onChange = () => {},
+  options = {},
+  mapStyle,
+  mapView,
+  inspectModeEnabled,
+  highlightedLayer,
+  replaceAccessTokens,
+  t,
+}: MapMaplibreGlInternalProps) => {
+  const container = useRef<HTMLDivElement | null>(null);
 
-  shouldComponentUpdate(nextProps: MapMaplibreGlInternalProps, nextState: MapMaplibreGlState) {
-    let should = false;
-    try {
-      should = JSON.stringify(this.props) !== JSON.stringify(nextProps) || JSON.stringify(this.state) !== JSON.stringify(nextState);
-    } catch(_e) {
-      // no biggie, carry on
-    }
-    return should;
-  }
+  // These used to live in `this.state`, but were never able to trigger a
+  // re-render: `shouldComponentUpdate` stringified the state, which throws for
+  // the (circular) maplibre `Map`, so the comparison was swallowed and the
+  // component only ever re-rendered on prop changes. They are imperative
+  // handles, so they are refs here and mutating them does not re-render.
+  const map = useRef<Map | null>(null);
+  const inspect = useRef<MaplibreInspect | null>(null);
+  const geocoder = useRef<MaplibreGeocoder | null>(null);
+  const zoomControl = useRef<ZoomControl | null>(null);
+  const zoom = useRef<number | undefined>(undefined);
 
-  componentDidUpdate() {
-    const map = this.state.map;
+  // `componentDidUpdate` did not run on mount, so neither may the effect below.
+  const hasMounted = useRef(false);
 
-    const styleWithTokens = this.props.replaceAccessTokens(this.props.mapStyle);
-    if (map) {
-      // Maplibre GL now does diffing natively so we don't need to calculate
-      // the necessary operations ourselves!
-      // We also need to update the style for inspect to work properly
-      map.setStyle(styleWithTokens, {diff: true});
-      map.showTileBoundaries = this.props.options?.showTileBoundaries!;
-      map.showCollisionBoxes = this.props.options?.showCollisionBoxes!;
-      map.showOverdrawInspector = this.props.options?.showOverdrawInspector!;
+  const [, forceUpdate] = useReducer((tick: number) => tick + 1, 0);
 
-      // set the map view when the prop was updated from outside
-      if (this.props.mapView._from === "app") {
-        map.jumpTo(this.props.mapView);
-      }
-    }
+  // The maplibre event handlers/callbacks below are registered once (on mount)
+  // but read `this.props` at call time in the class version, so they must not
+  // close over the props of the first render.
+  const latestProps = useRef({onDataChange, onLayerSelect, onChange, mapStyle, inspectModeEnabled, highlightedLayer, t});
+  latestProps.current = {onDataChange, onLayerSelect, onChange, mapStyle, inspectModeEnabled, highlightedLayer, t};
 
-    if(this.state.inspect && this.props.inspectModeEnabled !== this.state.inspect._showInspectMap) {
-      this.state.inspect.toggleInspector();
-    }
-    if (this.state.inspect && this.props.inspectModeEnabled) {
-      this.state.inspect.setOriginalStyle(styleWithTokens);
-      // In case the sources are the same, there's a need to refresh the style
-      setTimeout(() => {
-        this.state.inspect!.render();
-      }, 500);
-    }
+  const onLayerSelectById = useCallback((id: string) => {
+    const index = latestProps.current.mapStyle.layers.findIndex(layer => layer.id === id);
+    latestProps.current.onLayerSelect(index);
+  }, []);
 
-  }
-
-  componentDidMount() {
-    const mapOpts = {
-      ...this.props.options,
-      container: this.container!,
-      style: this.props.mapStyle,
-      hash: true,
-      maxZoom: 24,
-      // make root relative urls in stylefiles work as maplibre gl js does
-      // not support this for everything:
-      // https://github.com/maplibre/maplibre-gl-js/issues/6818
-      transformRequest: (url) => {
-        if (url.startsWith("/")) {
-          url = `${window.location.origin}${url}`;
-        }
-        return { url };
-      },
-      // setting to always load glyphs of CJK fonts from server
-      // https://maplibre.org/maplibre-gl-js/docs/examples/local-ideographs/
-      localIdeographFontFamily: false
-    } satisfies MapOptions;
-
-    const protocol = new Protocol({metadata: true});
-    MapLibreGl.addProtocol("pmtiles",protocol.tile);
-    const map = new MapLibreGl.Map(mapOpts);
-
-    const mapViewChange = () => {
-      const center = map.getCenter();
-      const zoom = map.getZoom();
-      this.props.onChange({center, zoom, _from: "map"});
-    };
-    mapViewChange();
-
-    map.showTileBoundaries = mapOpts.showTileBoundaries!;
-    map.showCollisionBoxes = mapOpts.showCollisionBoxes!;
-    map.showOverdrawInspector = mapOpts.showOverdrawInspector!;
-
-    const geocoder = this.initGeocoder(map);
-
-    const zoomControl = new ZoomControl();
-    map.addControl(zoomControl, "top-right");
-
-    const nav = new MapLibreGl.NavigationControl({visualizePitch:true});
-    map.addControl(nav, "top-right");
-
-    const tmpNode = document.createElement("div");
-    const root = createRoot(tmpNode);
-
-    const inspectPopup = new MapLibreGl.Popup({
-      closeOnClick: false
-    });
-
-    const inspect = new MaplibreInspect({
-      popup: inspectPopup,
-      showMapPopup: true,
-      showMapPopupOnHover: false,
-      showInspectMapPopupOnHover: true,
-      showInspectButton: false,
-      blockHoverPopupOnClick: true,
-      assignLayerColor: (layerId: string, alpha: number) => {
-        return Color(colors.brightColor(layerId, alpha)).desaturate(0.5).string();
-      },
-      buildInspectStyle: (originalMapStyle: StyleSpecification, coloredLayers: HighlightedLayer[]) => buildInspectStyle(originalMapStyle, coloredLayers, this.props.highlightedLayer),
-      renderPopup: (features: InspectFeature[]) => {
-        if(this.props.inspectModeEnabled) {
-          inspectPopup.once("open", () => {
-            root.render(<MapMaplibreGlFeaturePropertyPopup features={features} />);
-          });
-          return tmpNode;
-        } else {
-          inspectPopup.once("open", () => {
-            root.render(<MapMaplibreGlLayerPopup
-              features={features}
-              onLayerSelect={this.onLayerSelectById}
-              zoom={this.state.zoom}
-            />,);
-          });
-          return tmpNode;
-        }
-      }
-    });
-    map.addControl(inspect);
-
-    map.on("style.load", () => {
-      this.setState({
-        map,
-        inspect,
-        geocoder,
-        zoomControl,
-        zoom: map.getZoom()
-      });
-    });
-
-    map.on("data", e => {
-      if(e.dataType !== "tile") return;
-      this.props.onDataChange!({
-        map: this.state.map
-      });
-    });
-
-    map.on("error", e => {
-      console.log("ERROR", e);
-    });
-
-    map.on("zoom", _e => {
-      this.setState({
-        zoom: map.getZoom()
-      });
-    });
-
-    map.on("dragend", mapViewChange);
-    map.on("zoomend", mapViewChange);
-  }
-
-  onLayerSelectById = (id: string) => {
-    const index = this.props.mapStyle.layers.findIndex(layer => layer.id === id);
-    this.props.onLayerSelect(index);
-  };
-
-  initGeocoder(map: Map) {
+  const initGeocoder = useCallback((mapInstance: Map) => {
     const geocoderConfig = {
       forwardGeocode: async (config: MaplibreGeocoderApiConfig) => {
         const features = [];
@@ -300,26 +166,190 @@ class MapMaplibreGlInternal extends React.Component<MapMaplibreGlInternalProps,
         };
       },
     } as unknown as MaplibreGeocoderApi;
-    const geocoder = new MaplibreGeocoder(geocoderConfig, {
-      placeholder: this.props.t("Search"),
+    const geocoderInstance = new MaplibreGeocoder(geocoderConfig, {
+      placeholder: latestProps.current.t("Search"),
       maplibregl: MapLibreGl,
     });
-    map.addControl(geocoder, "top-left");
-    return geocoder;
-  }
+    mapInstance.addControl(geocoderInstance, "top-left");
+    return geocoderInstance;
+  }, []);
 
-  render() {
-    const t = this.props.t;
-    this.state.geocoder?.setPlaceholder(t("Search"));
-    this.state.zoomControl?.setLabel(t("Zoom:"));
-    return <div
-      className="maputnik-map__map"
-      role="region"
-      aria-label={t("Map view")}
-      ref={x => {this.container = x;}}
-      data-wd-key="maplibre:map"
-    ></div>;
-  }
-}
+  // Was the `i18next.on("languageChanged", () => this.forceUpdate())` in the
+  // constructor. `forceUpdate` bypassed `shouldComponentUpdate`; a state update
+  // likewise bypasses `React.memo`.
+  useEffect(() => {
+    const onLanguageChanged = () => {
+      forceUpdate();
+    };
+    i18next.on("languageChanged", onLanguageChanged);
+    return () => {
+      i18next.off("languageChanged", onLanguageChanged);
+    };
+  }, []);
 
-export const MapMaplibreGl = withTranslation()(MapMaplibreGlInternal);
+  // componentDidMount
+  useEffect(() => {
+    const mapOpts = {
+      ...options,
+      container: container.current!,
+      style: mapStyle,
+      hash: true,
+      maxZoom: 24,
+      // make root relative urls in stylefiles work as maplibre gl js does
+      // not support this for everything:
+      // https://github.com/maplibre/maplibre-gl-js/issues/6818
+      transformRequest: (url) => {
+        if (url.startsWith("/")) {
+          url = `${window.location.origin}${url}`;
+        }
+        return { url };
+      },
+      // setting to always load glyphs of CJK fonts from server
+      // https://maplibre.org/maplibre-gl-js/docs/examples/local-ideographs/
+      localIdeographFontFamily: false
+    } satisfies MapOptions;
+
+    const protocol = new Protocol({metadata: true});
+    MapLibreGl.addProtocol("pmtiles",protocol.tile);
+    const mapInstance = new MapLibreGl.Map(mapOpts);
+
+    const mapViewChange = () => {
+      const center = mapInstance.getCenter();
+      const currentZoom = mapInstance.getZoom();
+      latestProps.current.onChange({center, zoom: currentZoom, _from: "map"});
+    };
+    mapViewChange();
+
+    mapInstance.showTileBoundaries = mapOpts.showTileBoundaries!;
+    mapInstance.showCollisionBoxes = mapOpts.showCollisionBoxes!;
+    mapInstance.showOverdrawInspector = mapOpts.showOverdrawInspector!;
+
+    const geocoderInstance = initGeocoder(mapInstance);
+
+    const zoomControlInstance = new ZoomControl();
+    mapInstance.addControl(zoomControlInstance, "top-right");
+
+    const nav = new MapLibreGl.NavigationControl({visualizePitch:true});
+    mapInstance.addControl(nav, "top-right");
+
+    const tmpNode = document.createElement("div");
+    const root = createRoot(tmpNode);
+
+    const inspectPopup = new MapLibreGl.Popup({
+      closeOnClick: false
+    });
+
+    const inspectInstance = new MaplibreInspect({
+      popup: inspectPopup,
+      showMapPopup: true,
+      showMapPopupOnHover: false,
+      showInspectMapPopupOnHover: true,
+      showInspectButton: false,
+      blockHoverPopupOnClick: true,
+      assignLayerColor: (layerId: string, alpha: number) => {
+        return Color(colors.brightColor(layerId, alpha)).desaturate(0.5).string();
+      },
+      buildInspectStyle: (originalMapStyle: StyleSpecification, coloredLayers: HighlightedLayer[]) => buildInspectStyle(originalMapStyle, coloredLayers, latestProps.current.highlightedLayer),
+      renderPopup: (features: InspectFeature[]) => {
+        if(latestProps.current.inspectModeEnabled) {
+          inspectPopup.once("open", () => {
+            root.render(<MapMaplibreGlFeaturePropertyPopup features={features} />);
+          });
+          return tmpNode;
+        } else {
+          inspectPopup.once("open", () => {
+            root.render(<MapMaplibreGlLayerPopup
+              features={features}
+              onLayerSelect={onLayerSelectById}
+              zoom={zoom.current}
+            />,);
+          });
+          return tmpNode;
+        }
+      }
+    });
+    mapInstance.addControl(inspectInstance);
+
+    mapInstance.on("style.load", () => {
+      map.current = mapInstance;
+      inspect.current = inspectInstance;
+      geocoder.current = geocoderInstance;
+      zoomControl.current = zoomControlInstance;
+      zoom.current = mapInstance.getZoom();
+    });
+
+    mapInstance.on("data", e => {
+      if(e.dataType !== "tile") return;
+      latestProps.current.onDataChange!({
+        map: map.current
+      });
+    });
+
+    mapInstance.on("error", e => {
+      console.log("ERROR", e);
+    });
+
+    mapInstance.on("zoom", _e => {
+      zoom.current = mapInstance.getZoom();
+    });
+
+    mapInstance.on("dragend", mapViewChange);
+    mapInstance.on("zoomend", mapViewChange);
+    // Mount only, exactly like componentDidMount: the map is created from the
+    // props of the first render and kept up to date imperatively below (the
+    // handlers read `latestProps`, so no prop belongs in the dependencies). The
+    // class had no componentWillUnmount, so there is no teardown here either.
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- mount-only: adding mapStyle/options would re-create the map
+  }, [initGeocoder, onLayerSelectById]);
+
+  // componentDidUpdate. It had no `prevProps` guards, so it ran after *every*
+  // re-render; the equivalent is an effect without a dependency array. Since the
+  // component only re-renders when `arePropsEqual` reports a prop change (or on
+  // a language change, as before), this runs exactly as often as it used to.
+  useEffect(() => {
+    if (!hasMounted.current) {
+      // componentDidUpdate does not run on mount.
+      hasMounted.current = true;
+      return;
+    }
+
+    const styleWithTokens = replaceAccessTokens(mapStyle);
+    if (map.current) {
+      // Maplibre GL now does diffing natively so we don't need to calculate
+      // the necessary operations ourselves!
+      // We also need to update the style for inspect to work properly
+      map.current.setStyle(styleWithTokens, {diff: true});
+      map.current.showTileBoundaries = options?.showTileBoundaries!;
+      map.current.showCollisionBoxes = options?.showCollisionBoxes!;
+      map.current.showOverdrawInspector = options?.showOverdrawInspector!;
+
+      // set the map view when the prop was updated from outside
+      if (mapView._from === "app") {
+        map.current.jumpTo(mapView);
+      }
+    }
+
+    if(inspect.current && inspectModeEnabled !== inspect.current._showInspectMap) {
+      inspect.current.toggleInspector();
+    }
+    if (inspect.current && inspectModeEnabled) {
+      inspect.current.setOriginalStyle(styleWithTokens);
+      // In case the sources are the same, there's a need to refresh the style
+      setTimeout(() => {
+        inspect.current!.render();
+      }, 500);
+    }
+  });
+
+  geocoder.current?.setPlaceholder(t("Search"));
+  zoomControl.current?.setLabel(t("Zoom:"));
+  return <div
+    className="maputnik-map__map"
+    role="region"
+    aria-label={t("Map view")}
+    ref={container}
+    data-wd-key="maplibre:map"
+  ></div>;
+};
+
+export const MapMaplibreGl = withTranslation()(React.memo(MapMaplibreGlInternal, arePropsEqual));

src/components/MapMaplibreGlFeaturePropertyPopup.tsx

@@ -63,15 +63,13 @@ type FeaturePropertyPopupProps = {
   features: InspectFeature[]
 };
 
-export class FeaturePropertyPopup extends React.Component<FeaturePropertyPopupProps> {
-  render() {
-    const features = removeDuplicatedFeatures(this.props.features);
-    return <div className="maputnik-feature-property-popup" dir="ltr" data-wd-key="feature-property-popup">
-      <table className="maputnik-popup-table">
-        <tbody>
-          {features.map(renderFeature)}
-        </tbody>
-      </table>
-    </div>;
-  }
-}
+export const FeaturePropertyPopup: React.FC<FeaturePropertyPopupProps> = (props) => {
+  const features = removeDuplicatedFeatures(props.features);
+  return <div className="maputnik-feature-property-popup" dir="ltr" data-wd-key="feature-property-popup">
+    <table className="maputnik-popup-table">
+      <tbody>
+        {features.map(renderFeature)}
+      </tbody>
+    </table>
+  </div>;
+};

src/components/MapMaplibreGlLayerPopup.tsx

@@ -32,8 +32,8 @@ type FeatureLayerPopupProps = {
   zoom?: number
 };
 
-export class FeatureLayerPopup extends React.Component<FeatureLayerPopupProps> {
-  _getFeatureColor(feature: InspectFeature, _zoom?: number) {
+export const FeatureLayerPopup: React.FC<FeatureLayerPopupProps> = (props) => {
+  function _getFeatureColor(feature: InspectFeature, _zoom?: number) {
     // Guard because openlayers won't have this
     if (!feature.layer.paint) {
       return;
@@ -65,47 +65,45 @@ export class FeatureLayerPopup extends React.Component<FeatureLayerPopupProps> {
     }
   }
 
-  render() {
-    const sources = groupFeaturesBySourceLayer(this.props.features);
+  const sources = groupFeaturesBySourceLayer(props.features);
 
-    const items = Object.keys(sources).map(vectorLayerId => {
-      const layers = sources[vectorLayerId].map((feature: InspectFeature, idx: number) => {
-        const featureColor = this._getFeatureColor(feature, this.props.zoom);
+  const items = Object.keys(sources).map(vectorLayerId => {
+    const layers = sources[vectorLayerId].map((feature: InspectFeature, idx: number) => {
+      const featureColor = _getFeatureColor(feature, props.zoom);
 
-        return <div
-          key={idx}
-          className="maputnik-popup-layer"
+      return <div
+        key={idx}
+        className="maputnik-popup-layer"
+      >
+        <div
+          className="maputnik-popup-layer__swatch"
+          style={{background: featureColor}}
+        ></div>
+        <label
+          className="maputnik-popup-layer__label"
+          onClick={() => {
+            props.onLayerSelect(feature.layer.id);
+          }}
         >
-          <div
-            className="maputnik-popup-layer__swatch"
-            style={{background: featureColor}}
-          ></div>
-          <label
-            className="maputnik-popup-layer__label"
-            onClick={() => {
-              this.props.onLayerSelect(feature.layer.id);
-            }}
-          >
-            {feature.layer.type &&
-              <IconLayer type={feature.layer.type} style={{
-                width: 14,
-                height: 14,
-                paddingRight: 3
-              }}/>
-            }
-            {feature.layer.id}
-            {feature.counter && <span> × {feature.counter}</span>}
-          </label>
-        </div>;
-      });
-      return <div key={vectorLayerId}>
-        <div className="maputnik-popup-layer-id">{vectorLayerId}</div>
-        {layers}
+          {feature.layer.type &&
+            <IconLayer type={feature.layer.type} style={{
+              width: 14,
+              height: 14,
+              paddingRight: 3
+            }}/>
+          }
+          {feature.layer.id}
+          {feature.counter && <span> × {feature.counter}</span>}
+        </label>
       </div>;
     });
-
-    return <div className="maputnik-feature-layer-popup" data-wd-key="feature-layer-popup" dir="ltr">
-      {items}
+    return <div key={vectorLayerId}>
+      <div className="maputnik-popup-layer-id">{vectorLayerId}</div>
+      {layers}
     </div>;
-  }
-}
+  });
+
+  return <div className="maputnik-feature-layer-popup" data-wd-key="feature-layer-popup" dir="ltr">
+    {items}
+  </div>;
+};

src/components/MapOpenLayers.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import {useCallback, useEffect, useMemo, useRef, useState} from "react";
 import {throttle} from "lodash";
 import { type WithTranslation, withTranslation } from "react-i18next";
 
@@ -35,56 +35,52 @@ type MapOpenLayersInternalProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-type MapOpenLayersState = {
-  zoom: string
-  rotation: string
-  cursor: string[]
-  center: string[]
-  selectedFeatures?: any[]
-};
+const MapOpenLayersInternal = ({
+  onLayerSelect = () => {},
+  mapStyle,
+  style,
+  debugToolbox,
+  replaceAccessTokens,
+  onChange,
+  t,
+}: MapOpenLayersInternalProps) => {
+  const [zoom, setZoom] = useState("0");
+  const [rotation, setRotation] = useState("0");
+  const [cursor, setCursor] = useState<string[]>([]);
+  const [center, setCenter] = useState<string[]>([]);
+  // Never assigned in the class version either, kept for the popup below.
+  const [selectedFeatures] = useState<any[] | undefined>(undefined);
 
-class MapOpenLayersInternal extends React.Component<MapOpenLayersInternalProps, MapOpenLayersState> {
-  static defaultProps = {
-    onMapLoaded: () => {},
-    onDataChange: () => {},
-    onLayerSelect: () => {},
-  };
-  updateStyle: any;
-  map: any;
-  container: HTMLDivElement | null = null;
-  overlay: Overlay | undefined;
-  popupContainer: HTMLElement | null = null;
+  // Imperative handles: they were plain instance fields, so they are refs and
+  // mutating them must not re-render.
+  const map = useRef<Map | null>(null);
+  const container = useRef<HTMLDivElement | null>(null);
+  const overlay = useRef<Overlay | undefined>(undefined);
+  const popupContainer = useRef<HTMLDivElement | null>(null);
 
-  constructor(props: MapOpenLayersInternalProps) {
-    super(props);
-    this.state = {
-      zoom: "0",
-      rotation: "0",
-      cursor: [] as string[],
-      center: [],
-    };
-    this.updateStyle = throttle(this._updateStyle.bind(this), 200);
-  }
+  // componentDidUpdate did not run on mount, and componentDidMount already
+  // applies the initial style, so the style effect below must skip the mount.
+  const hasMounted = useRef(false);
 
-  _updateStyle(newMapStyle: StyleSpecification) {
-    if(!this.map) return;
+  // The openlayers event handlers are registered on mount but read `this.props`
+  // at call time in the class version.
+  const latestProps = useRef({mapStyle, replaceAccessTokens, onChange});
+  latestProps.current = {mapStyle, replaceAccessTokens, onChange};
+
+  // Was `this.updateStyle = throttle(this._updateStyle.bind(this), 200)` in the
+  // constructor: created once per instance, so it is memoized once here.
+  const updateStyle = useMemo(() => throttle((newMapStyle: StyleSpecification) => {
+    if(!map.current) return;
 
     // See <https://github.com/openlayers/ol-mapbox-style/issues/215#issuecomment-493198815>
-    this.map.getLayers().clear();
-    apply(this.map, newMapStyle);
-  }
+    map.current.getLayers().clear();
+    apply(map.current, newMapStyle);
+  }, 200), []);
 
-  componentDidUpdate(prevProps: MapOpenLayersInternalProps) {
-    if (this.props.mapStyle !== prevProps.mapStyle) {
-      this.updateStyle(
-        this.props.replaceAccessTokens(this.props.mapStyle)
-      );
-    }
-  }
-
-  componentDidMount() {
-    this.overlay = new Overlay({
-      element: this.popupContainer!,
+  // componentDidMount
+  useEffect(() => {
+    overlay.current = new Overlay({
+      element: popupContainer.current!,
       autoPan: {
         animation: {
           duration: 250
@@ -92,116 +88,131 @@ class MapOpenLayersInternal extends React.Component<MapOpenLayersInternalProps,
       },
     });
 
-    const map = new Map({
-      target: this.container!,
-      overlays: [this.overlay],
+    const mapInstance = new Map({
+      target: container.current!,
+      overlays: [overlay.current],
       view: new View({
         zoom: 1,
         center: [180, -90],
       })
     });
 
-    map.on("pointermove", (evt) => {
+    mapInstance.on("pointermove", (evt) => {
       const coords = toLonLat(evt.coordinate);
-      this.setState({
-        cursor: [
-          coords[0].toFixed(2),
-          coords[1].toFixed(2)
-        ]
-      });
+      setCursor([
+        coords[0].toFixed(2),
+        coords[1].toFixed(2)
+      ]);
     });
 
     const onMoveEnd = () => {
-      const zoom = map.getView().getZoom();
-      const center = toLonLat(map.getView().getCenter()!);
+      const currentZoom = mapInstance.getView().getZoom();
+      const currentCenter = toLonLat(mapInstance.getView().getCenter()!);
 
-      this.props.onChange({
-        zoom,
+      latestProps.current.onChange({
+        zoom: currentZoom,
         center: {
-          lng: center[0],
-          lat: center[1],
+          lng: currentCenter[0],
+          lat: currentCenter[1],
         },
       });
     };
 
     onMoveEnd();
-    map.on("moveend", onMoveEnd);
+    mapInstance.on("moveend", onMoveEnd);
 
-    map.on("postrender", (_e) => {
-      const center = toLonLat(map.getView().getCenter()!);
-      this.setState({
-        center: [
-          center[0].toFixed(2),
-          center[1].toFixed(2),
-        ],
-        rotation: map.getView().getRotation().toFixed(2),
-        zoom: map.getView().getZoom()!.toFixed(2)
-      });
+    mapInstance.on("postrender", (_e) => {
+      const currentCenter = toLonLat(mapInstance.getView().getCenter()!);
+      setCenter([
+        currentCenter[0].toFixed(2),
+        currentCenter[1].toFixed(2),
+      ]);
+      setRotation(mapInstance.getView().getRotation().toFixed(2));
+      setZoom(mapInstance.getView().getZoom()!.toFixed(2));
     });
 
 
 
-    this.map = map;
-    this.updateStyle(
-      this.props.replaceAccessTokens(this.props.mapStyle)
+    map.current = mapInstance;
+    updateStyle(
+      latestProps.current.replaceAccessTokens(latestProps.current.mapStyle) as StyleSpecification
     );
-  }
+    // Mount only, like componentDidMount. The class had no componentWillUnmount,
+    // so there is no teardown here either. The props read above are read from
+    // latestProps/the first render on purpose, so they are not dependencies.
+  }, [updateStyle]);
 
-  closeOverlay = (e: any) => {
+  // componentDidUpdate: `if (this.props.mapStyle !== prevProps.mapStyle)`.
+  useEffect(() => {
+    if (!hasMounted.current) {
+      // componentDidUpdate does not run on mount; componentDidMount already
+      // applied the initial style, and applying it twice would push a second
+      // (throttled) clear + apply through ol-mapbox-style.
+      hasMounted.current = true;
+      return;
+    }
+    updateStyle(
+      replaceAccessTokens(mapStyle) as StyleSpecification
+    );
+    // `replaceAccessTokens` is deliberately *not* a dependency: the parent
+    // re-creates it on every render, so depending on it would re-apply the style
+    // on every render instead of only when `mapStyle` changes, which is exactly
+    // what the `this.props.mapStyle !== prevProps.mapStyle` guard checked.
+    // eslint-disable-next-line react-hooks/exhaustive-deps -- see above: replaceAccessTokens is a new identity each render
+  }, [mapStyle, updateStyle]);
+
+  const closeOverlay = useCallback((e: any) => {
     e.target.blur();
-    this.overlay!.setPosition(undefined);
-  };
+    overlay.current!.setPosition(undefined);
+  }, []);
 
-  render() {
-    const t = this.props.t;
-    return <div className="maputnik-ol-container">
-      <div
-        ref={x => {this.popupContainer = x;}}
-        style={{background: "black"}}
-        className="maputnik-popup"
+  return <div className="maputnik-ol-container">
+    <div
+      ref={popupContainer}
+      style={{background: "black"}}
+      className="maputnik-popup"
+    >
+      <button
+        className="maplibregl-popup-close-button"
+        onClick={closeOverlay}
+        aria-label={t("Close popup")}
       >
-        <button
-          className="maplibregl-popup-close-button"
-          onClick={this.closeOverlay}
-          aria-label={t("Close popup")}
-        >
-          ×
-        </button>
-        <MapMaplibreGlLayerPopup
-          features={this.state.selectedFeatures || []}
-          onLayerSelect={this.props.onLayerSelect}
-        />
-      </div>
-      <div className="maputnik-ol-zoom">
-        {t("Zoom:")} {this.state.zoom}
-      </div>
-      {this.props.debugToolbox &&
-        <div className="maputnik-ol-debug">
-          <div>
-            <label>{t("cursor:")} </label>
-            <span>{renderCoords(this.state.cursor)}</span>
-          </div>
-          <div>
-            <label>{t("center:")} </label>
-            <span>{renderCoords(this.state.center)}</span>
-          </div>
-          <div>
-            <label>{t("rotation:")} </label>
-            <span>{this.state.rotation}</span>
-          </div>
+        ×
+      </button>
+      <MapMaplibreGlLayerPopup
+        features={selectedFeatures || []}
+        onLayerSelect={onLayerSelect}
+      />
+    </div>
+    <div className="maputnik-ol-zoom">
+      {t("Zoom:")} {zoom}
+    </div>
+    {debugToolbox &&
+      <div className="maputnik-ol-debug">
+        <div>
+          <label>{t("cursor:")} </label>
+          <span>{renderCoords(cursor)}</span>
+        </div>
+        <div>
+          <label>{t("center:")} </label>
+          <span>{renderCoords(center)}</span>
+        </div>
+        <div>
+          <label>{t("rotation:")} </label>
+          <span>{rotation}</span>
         </div>
-      }
-      <div
-        className="maputnik-ol"
-        ref={x => {this.container = x;}}
-        role="region"
-        aria-label={t("Map view")}
-        style={{
-          ...this.props.style,
-        }}>
       </div>
-    </div>;
-  }
-}
+    }
+    <div
+      className="maputnik-ol"
+      ref={container}
+      role="region"
+      aria-label={t("Map view")}
+      style={{
+        ...style,
+      }}>
+    </div>
+  </div>;
+};
 
 export const MapOpenLayers = withTranslation()(MapOpenLayersInternal);

src/components/PropertyGroup.tsx

@@ -40,37 +40,35 @@ type PropertyGroupProps = {
   errors?: MappedLayerErrors
 };
 
-export class PropertyGroup extends React.Component<PropertyGroupProps> {
-  onPropertyChange = (property: string, newValue: any) => {
-    const group = getGroupName(this.props.spec, this.props.layer.type, property);
-    this.props.onChange(group ,property, newValue);
+export const PropertyGroup: React.FC<PropertyGroupProps> = (props) => {
+  const onPropertyChange = (property: string, newValue: any) => {
+    const group = getGroupName(props.spec, props.layer.type, property);
+    props.onChange(group ,property, newValue);
   };
 
-  render() {
-    const {errors} = this.props;
-    const fields = this.props.groupFields.map(fieldName => {
-      const fieldSpec = getFieldSpec(this.props.spec, this.props.layer.type, fieldName);
+  const {errors} = props;
+  const fields = props.groupFields.map(fieldName => {
+    const fieldSpec = getFieldSpec(props.spec, props.layer.type, fieldName);
 
-      const paint = this.props.layer.paint || {};
-      const layout = this.props.layer.layout || {};
-      const fieldValue = fieldName in paint
-        ? paint[fieldName as keyof typeof paint]
-        : layout[fieldName as keyof typeof layout];
-      const fieldType = fieldName in paint ? "paint" : "layout";
+    const paint = props.layer.paint || {};
+    const layout = props.layer.layout || {};
+    const fieldValue = fieldName in paint
+      ? paint[fieldName as keyof typeof paint]
+      : layout[fieldName as keyof typeof layout];
+    const fieldType = fieldName in paint ? "paint" : "layout";
 
-      return <FieldFunction
-        errors={errors}
-        onChange={this.onPropertyChange}
-        key={fieldName}
-        fieldName={fieldName}
-        value={fieldValue}
-        fieldType={fieldType}
-        fieldSpec={fieldSpec}
-      />;
-    });
+    return <FieldFunction
+      errors={errors}
+      onChange={onPropertyChange}
+      key={fieldName}
+      fieldName={fieldName}
+      value={fieldValue}
+      fieldType={fieldType}
+      fieldSpec={fieldSpec}
+    />;
+  });
 
-    return <div className="maputnik-property-group">
-      {fields}
-    </div>;
-  }
-}
+  return <div className="maputnik-property-group">
+    {fields}
+  </div>;
+};

src/components/ScrollContainer.tsx

@@ -4,10 +4,8 @@ type ScrollContainerProps = {
   children?: React.ReactNode
 };
 
-export class ScrollContainer extends React.Component<ScrollContainerProps> {
-  render() {
-    return <div className="maputnik-scroll-container">
-      {this.props.children}
-    </div>;
-  }
-}
+export const ScrollContainer: React.FC<ScrollContainerProps> = (props) => {
+  return <div className="maputnik-scroll-container">
+    {props.children}
+  </div>;
+};

src/components/SingleFilterEditor.tsx

@@ -40,53 +40,50 @@ type SingleFilterEditorProps = {
   properties?: {[key: string]: string}
 };
 
-export class SingleFilterEditor extends React.Component<SingleFilterEditorProps> {
-  static defaultProps = {
-    properties: {},
-  };
-
-  onFilterPartChanged(filterOp: string, propertyName: string, filterArgs: string[]) {
+export const SingleFilterEditor: React.FC<SingleFilterEditorProps> = ({
+  properties = {},
+  ...props
+}) => {
+  function onFilterPartChanged(filterOp: string, propertyName: string, filterArgs: string[]) {
     let newFilter = [filterOp, propertyName, ...filterArgs.map(parseFilter)];
     if(filterOp === "has" || filterOp === "!has") {
       newFilter = [filterOp, propertyName];
     } else if(filterArgs.length === 0) {
       newFilter = [filterOp, propertyName, ""];
     }
-    this.props.onChange(newFilter);
+    props.onChange(newFilter);
   }
 
-  render() {
-    const f = this.props.filter;
-    const filterOp = f[0];
-    const propertyName = f[1];
-    const filterArgs = f.slice(2);
+  const f = props.filter;
+  const filterOp = f[0];
+  const propertyName = f[1];
+  const filterArgs = f.slice(2);
 
-    return <div className="maputnik-filter-editor-single">
-      <div className="maputnik-filter-editor-property">
-        <InputAutocomplete
-          aria-label="key"
-          value={propertyName}
-          options={Object.keys(this.props.properties!).map(propName => [propName, propName])}
-          onChange={(newPropertyName: string) => this.onFilterPartChanged(filterOp, newPropertyName, filterArgs)}
-        />
-      </div>
-      <div className="maputnik-filter-editor-operator">
-        <InputSelect
-          aria-label="function"
-          value={filterOp}
-          onChange={(newFilterOp: string) => this.onFilterPartChanged(newFilterOp, propertyName, filterArgs)}
-          options={otherFilterOps}
-        />
-      </div>
-      {filterArgs.length > 0 &&
-      <div className="maputnik-filter-editor-args">
-        <InputString
-          aria-label="value"
-          value={filterArgs.join(",")}
-          onChange={(v: string) => this.onFilterPartChanged(filterOp, propertyName, v.split(","))}
-        />
-      </div>
-      }
-    </div>;
-  }
-}
+  return <div className="maputnik-filter-editor-single">
+    <div className="maputnik-filter-editor-property">
+      <InputAutocomplete
+        aria-label="key"
+        value={propertyName}
+        options={Object.keys(properties).map(propName => [propName, propName])}
+        onChange={(newPropertyName: string) => onFilterPartChanged(filterOp, newPropertyName, filterArgs)}
+      />
+    </div>
+    <div className="maputnik-filter-editor-operator">
+      <InputSelect
+        aria-label="function"
+        value={filterOp}
+        onChange={(newFilterOp: string) => onFilterPartChanged(newFilterOp, propertyName, filterArgs)}
+        options={otherFilterOps}
+      />
+    </div>
+    {filterArgs.length > 0 &&
+    <div className="maputnik-filter-editor-args">
+      <InputString
+        aria-label="value"
+        value={filterArgs.join(",")}
+        onChange={(v: string) => onFilterPartChanged(filterOp, propertyName, v.split(","))}
+      />
+    </div>
+    }
+  </div>;
+};

src/components/SmallError.tsx

@@ -7,15 +7,13 @@ type SmallErrorInternalProps = {
   children?: React.ReactNode
 } & WithTranslation;
 
-class SmallErrorInternal extends React.Component<SmallErrorInternalProps> {
-  render () {
-    const t = this.props.t;
-    return (
-      <div className="SmallError">
-        {t("Error:")} {this.props.children}
-      </div>
-    );
-  }
-}
+const SmallErrorInternal: React.FC<SmallErrorInternalProps> = (props) => {
+  const t = props.t;
+  return (
+    <div className="SmallError">
+      {t("Error:")} {props.children}
+    </div>
+  );
+};
 
 export const SmallError = withTranslation()(SmallErrorInternal);

src/components/SpecProperty.tsx

@@ -19,30 +19,26 @@ type SpecPropertyProps = FieldSpecProps & {
 };
 
 
-export class SpecProperty extends React.Component<SpecPropertyProps> {
-  static defaultProps = {
-    errors: {},
-  };
+export const SpecProperty: React.FC<SpecPropertyProps> = (props) => {
+  const {errors = {}, fieldName, fieldType} = props;
 
-  render() {
-    const {errors, fieldName, fieldType} = this.props;
+  const functionBtn = <FunctionButtons
+    fieldSpec={props.fieldSpec}
+    onZoomClick={props.onZoomClick}
+    onDataClick={props.onDataClick}
+    onExpressionClick={props.onExpressionClick}
+    onElevationClick={props.onElevationClick}
+  />;
 
-    const functionBtn = <FunctionButtons
-      fieldSpec={this.props.fieldSpec}
-      onZoomClick={this.props.onZoomClick}
-      onDataClick={this.props.onDataClick}
-      onExpressionClick={this.props.onExpressionClick}
-      onElevationClick={this.props.onElevationClick}
-    />;
+  const error = errors[fieldType+"."+fieldName as any] as any;
 
-    const error = errors![fieldType+"."+fieldName as any] as any;
+  const propsWithDefaults = {...props, errors};
 
-    return <FieldSpec
-      {...this.props}
-      error={error}
-      fieldSpec={this.props.fieldSpec}
-      label={labelFromFieldName(this.props.fieldName || "")}
-      action={functionBtn}
-    />;
-  }
-}
+  return <FieldSpec
+    {...propsWithDefaults}
+    error={error}
+    fieldSpec={props.fieldSpec}
+    label={labelFromFieldName(props.fieldName || "")}
+    action={functionBtn}
+  />;
+};

src/components/ZoomProperty.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useRef } from "react";
 import { PiListPlusBold } from "react-icons/pi";
 import { TbMathFunction } from "react-icons/tb";
 import latest from "@maplibre/maplibre-gl-style-spec/dist/latest.json";
@@ -68,41 +68,21 @@ type ZoomPropertyState = {
   refs: {[key: number]: string}
 };
 
-class ZoomPropertyInternal extends React.Component<ZoomPropertyInternalProps, ZoomPropertyState> {
-  static defaultProps = {
-    errors: {},
-  };
+const ZoomPropertyInternal: React.FC<ZoomPropertyInternalProps> = ({ errors = {}, ...rest }) => {
+  const props = { errors, ...rest } as ZoomPropertyInternalProps;
 
-  state = {
-    refs: {} as {[key: number]: string}
-  };
-
-  componentDidMount() {
-    const newRefs = setStopRefs(this.props, this.state);
-
-    if(newRefs) {
-      this.setState({
-        refs: newRefs
-      });
-    }
-  }
-
-  static getDerivedStateFromProps(props: Readonly<ZoomPropertyInternalProps>, state: ZoomPropertyState) {
-    const newRefs = setStopRefs(props, state);
-    if(newRefs) {
-      return {
-        refs: newRefs
-      };
-    }
-    return null;
-  }
+  // The stop refs never reach the rendered output (the row key is derived from
+  // the stop itself), so they live in a ref rather than state: keeping them in
+  // state would mean setting state during render on every pass.
+  const refs = useRef<{[key: number]: string}>({});
+  refs.current = setStopRefs(props, { refs: refs.current });
 
   // Order the stops altering the refs to reflect their new position.
-  orderStopsByZoom(stops: ZoomWithStops["stops"]) {
+  function orderStopsByZoom(stops: ZoomWithStops["stops"]) {
     const mappedWithRef = stops
       .map((stop, idx) => {
         return {
-          ref: this.state.refs[idx],
+          ref: refs.current[idx],
           data: stop
         };
       })
@@ -116,145 +96,43 @@ class ZoomPropertyInternal extends React.Component<ZoomPropertyInternalProps, Zo
         newRefs[idx] = stop.ref;
       });
 
-    this.setState({
-      refs: newRefs
-    });
+    refs.current = newRefs;
 
     return mappedWithRef.map((item) => item.data);
   }
 
-  changeZoomStop(changeIdx: number, stopData: number | undefined, value: number) {
-    const stops = (this.props.value as ZoomWithStops).stops.slice(0);
+  function changeZoomStop(changeIdx: number, stopData: number | undefined, value: number) {
+    const stops = (props.value as ZoomWithStops).stops.slice(0);
     stops[changeIdx] = [stopData, value];
 
-    const orderedStops = this.orderStopsByZoom(stops);
+    const orderedStops = orderStopsByZoom(stops);
 
     const changedValue = {
-      ...this.props.value as ZoomWithStops,
+      ...props.value as ZoomWithStops,
       stops: orderedStops
     };
-    this.props.onChange!(this.props.fieldName, changedValue);
+    props.onChange!(props.fieldName, changedValue);
   }
 
-  changeBase(newValue: number | undefined) {
+  function changeBase(newValue: number | undefined) {
     const changedValue = {
-      ...this.props.value,
+      ...props.value,
       base: newValue
     };
 
     if (changedValue.base === undefined) {
       delete changedValue["base"];
     }
-    this.props.onChange!(this.props.fieldName, changedValue);
+    props.onChange!(props.fieldName, changedValue);
   }
 
-  changeDataType = (type: string) => {
-    if (type !== "interpolate" && this.props.onChangeToDataFunction) {
-      this.props.onChangeToDataFunction(type);
+  const changeDataType = (type: string) => {
+    if (type !== "interpolate" && props.onChangeToDataFunction) {
+      props.onChangeToDataFunction(type);
     }
   };
 
-  render() {
-    const t = this.props.t;
-    const zoomFields = this.props.value?.stops.map((stop, idx) => {
-      const zoomLevel = stop[0];
-      const value = stop[1];
-      const deleteStopBtn = <DeleteStopButton onClick={this.props.onDeleteStop?.bind(this, idx)} />;
-      return <tr
-        key={`${stop[0]}-${stop[1]}`}
-      >
-        <td>
-          <InputNumber
-            aria-label={t("Zoom")}
-            value={zoomLevel}
-            onChange={changedStop => this.changeZoomStop(idx, changedStop, value)}
-            min={0}
-            max={22}
-          />
-        </td>
-        <td>
-          <InputSpec
-            aria-label={t("Output value")}
-            fieldName={this.props.fieldName}
-            fieldSpec={this.props.fieldSpec as any}
-            value={value}
-            onChange={(_, newValue) => this.changeZoomStop(idx, zoomLevel, newValue as number)}
-          />
-        </td>
-        <td>
-          {deleteStopBtn}
-        </td>
-      </tr>;
-    });
-
-    // return <div className="maputnik-zoom-spec-property">
-    return <div className="maputnik-data-spec-block">
-      <fieldset className="maputnik-data-spec-property">
-        <legend>{labelFromFieldName(this.props.fieldName)}</legend>
-        <div className="maputnik-data-fieldset-inner">
-          <Block
-            label={t("Function")}
-            data-wd-key="function-type"
-          >
-            <div className="maputnik-data-spec-property-input">
-              <InputSelect
-                value={"interpolate"}
-                onChange={(propVal: string) => this.changeDataType(propVal)}
-                title={t("Select a type of data scale (default is 'categorical').")}
-                options={this.getDataFunctionTypes(this.props.fieldSpec!)}
-              />
-            </div>
-          </Block>
-          <Block
-            label={t("Base")}
-            data-wd-key="function-base"
-          >
-            <div className="maputnik-data-spec-property-input">
-              <InputSpec
-                fieldName={"base"}
-                fieldSpec={latest.function.base as typeof latest.function.base & { type: "number" }}
-                value={this.props.value?.base}
-                onChange={(_, newValue) => this.changeBase(newValue as number | undefined)}
-              />
-            </div>
-          </Block>
-          <div className="maputnik-function-stop">
-            <table className="maputnik-function-stop-table maputnik-function-stop-table--zoom">
-              <caption>{t("Stops")}</caption>
-              <thead>
-                <tr>
-                  <th>{t("Zoom")}</th>
-                  <th rowSpan={2}>{t("Output value")}</th>
-                </tr>
-              </thead>
-              <tbody>
-                {zoomFields}
-              </tbody>
-            </table>
-          </div>
-          <div className="maputnik-toolbox">
-            <InputButton
-              className="maputnik-add-stop"
-              onClick={this.props.onAddStop?.bind(this)}
-            >
-              <PiListPlusBold style={{ verticalAlign: "text-bottom" }} />
-              {t("Add stop")}
-            </InputButton>
-            <InputButton
-              className="maputnik-add-stop"
-              data-wd-key="convert-to-expression"
-              onClick={this.props.onExpressionClick?.bind(this)}
-            >
-              <TbMathFunction style={{ verticalAlign: "text-bottom" }} />
-              {t("Convert to expression")}
-            </InputButton>
-          </div>
-        </div>
-      </fieldset>
-    </div>;
-  }
-
-  getDataFunctionTypes(fieldSpec: {
+  function getDataFunctionTypes(fieldSpec: {
     "property-type"?: string
     "function-type"?: string
   }) {
@@ -265,6 +143,104 @@ class ZoomPropertyInternal extends React.Component<ZoomPropertyInternalProps, Zo
       return ["interpolate"];
     }
   }
-}
+
+  const t = props.t;
+  const zoomFields = props.value?.stops.map((stop, idx) => {
+    const zoomLevel = stop[0];
+    const value = stop[1];
+    const deleteStopBtn = <DeleteStopButton onClick={props.onDeleteStop?.bind(null, idx)} />;
+    return <tr
+      key={`${stop[0]}-${stop[1]}`}
+    >
+      <td>
+        <InputNumber
+          aria-label={t("Zoom")}
+          value={zoomLevel}
+          onChange={changedStop => changeZoomStop(idx, changedStop, value)}
+          min={0}
+          max={22}
+        />
+      </td>
+      <td>
+        <InputSpec
+          aria-label={t("Output value")}
+          fieldName={props.fieldName}
+          fieldSpec={props.fieldSpec as any}
+          value={value}
+          onChange={(_, newValue) => changeZoomStop(idx, zoomLevel, newValue as number)}
+        />
+      </td>
+      <td>
+        {deleteStopBtn}
+      </td>
+    </tr>;
+  });
+
+  // return <div className="maputnik-zoom-spec-property">
+  return <div className="maputnik-data-spec-block">
+    <fieldset className="maputnik-data-spec-property">
+      <legend>{labelFromFieldName(props.fieldName)}</legend>
+      <div className="maputnik-data-fieldset-inner">
+        <Block
+          label={t("Function")}
+          data-wd-key="function-type"
+        >
+          <div className="maputnik-data-spec-property-input">
+            <InputSelect
+              value={"interpolate"}
+              onChange={(propVal: string) => changeDataType(propVal)}
+              title={t("Select a type of data scale (default is 'categorical').")}
+              options={getDataFunctionTypes(props.fieldSpec!)}
+            />
+          </div>
+        </Block>
+        <Block
+          label={t("Base")}
+          data-wd-key="function-base"
+        >
+          <div className="maputnik-data-spec-property-input">
+            <InputSpec
+              fieldName={"base"}
+              fieldSpec={latest.function.base as typeof latest.function.base & { type: "number" }}
+              value={props.value?.base}
+              onChange={(_, newValue) => changeBase(newValue as number | undefined)}
+            />
+          </div>
+        </Block>
+        <div className="maputnik-function-stop">
+          <table className="maputnik-function-stop-table maputnik-function-stop-table--zoom">
+            <caption>{t("Stops")}</caption>
+            <thead>
+              <tr>
+                <th>{t("Zoom")}</th>
+                <th rowSpan={2}>{t("Output value")}</th>
+              </tr>
+            </thead>
+            <tbody>
+              {zoomFields}
+            </tbody>
+          </table>
+        </div>
+        <div className="maputnik-toolbox">
+          <InputButton
+            className="maputnik-add-stop"
+            onClick={props.onAddStop?.bind(null)}
+          >
+            <PiListPlusBold style={{ verticalAlign: "text-bottom" }} />
+            {t("Add stop")}
+          </InputButton>
+          <InputButton
+            className="maputnik-add-stop"
+            data-wd-key="convert-to-expression"
+            onClick={props.onExpressionClick?.bind(null)}
+          >
+            <TbMathFunction style={{ verticalAlign: "text-bottom" }} />
+            {t("Convert to expression")}
+          </InputButton>
+        </div>
+      </div>
+    </fieldset>
+  </div>;
+};
 
 export const ZoomProperty = withTranslation()(ZoomPropertyInternal);

src/components/modals/Modal.tsx

@@ -14,57 +14,51 @@ type ModalInternalProps = PropsWithChildren & {
 } & WithTranslation;
 
 
-class ModalInternal extends React.Component<ModalInternalProps> {
-  static defaultProps = {
-    underlayClickExits: true
-  };
-
+const ModalInternal: React.FC<ModalInternalProps> = ({underlayClickExits = true, ...props}) => {
   // See <https://github.com/maplibre/maputnik/issues/416>
-  onClose = () => {
+  const onClose = () => {
     if (document.activeElement) {
       (document.activeElement as HTMLElement).blur();
     }
 
     setTimeout(() => {
-      this.props.onOpenToggle();
+      props.onOpenToggle();
     }, 0);
   };
 
-  render() {
-    const t = this.props.t;
-    if(this.props.isOpen) {
-      return <AriaModal
-        titleText={this.props.title}
-        underlayClickExits={this.props.underlayClickExits}
-        data-wd-key={this.props["data-wd-key"]}
-        verticallyCenter={true}
-        onExit={this.onClose}
-        dialogClass='maputnik-modal-container'
+  const t = props.t;
+  if(props.isOpen) {
+    return <AriaModal
+      titleText={props.title}
+      underlayClickExits={underlayClickExits}
+      data-wd-key={props["data-wd-key"]}
+      verticallyCenter={true}
+      onExit={onClose}
+      dialogClass='maputnik-modal-container'
+    >
+      <div className={classnames("maputnik-modal", props.className)}
+        data-wd-key={props["data-wd-key"]}
       >
-        <div className={classnames("maputnik-modal", this.props.className)}
-          data-wd-key={this.props["data-wd-key"]}
-        >
-          <header className="maputnik-modal-header">
-            <h1 className="maputnik-modal-header-title">{this.props.title}</h1>
-            <span className="maputnik-space"></span>
-            <button className="maputnik-modal-header-toggle"
-              title={t("Close modal")}
-              onClick={this.onClose}
-              data-wd-key={this.props["data-wd-key"]+".close-modal"}
-            >
-              <MdClose />
-            </button>
-          </header>
-          <div className="maputnik-modal-scroller">
-            <div className="maputnik-modal-content">{this.props.children}</div>
-          </div>
+        <header className="maputnik-modal-header">
+          <h1 className="maputnik-modal-header-title">{props.title}</h1>
+          <span className="maputnik-space"></span>
+          <button className="maputnik-modal-header-toggle"
+            title={t("Close modal")}
+            onClick={onClose}
+            data-wd-key={props["data-wd-key"]+".close-modal"}
+          >
+            <MdClose />
+          </button>
+        </header>
+        <div className="maputnik-modal-scroller">
+          <div className="maputnik-modal-content">{props.children}</div>
         </div>
-      </AriaModal>;
-    }
-    else {
-      return false;
-    }
+      </div>
+    </AriaModal>;
   }
-}
+  else {
+    return false;
+  }
+};
 
 export const Modal = withTranslation()(ModalInternal);

src/components/modals/ModalAdd.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useEffect, useRef, useState } from "react";
 import { type WithTranslation, withTranslation } from "react-i18next";
 import type {LayerSpecification, SourceSpecification} from "maplibre-gl";
 
@@ -27,169 +27,166 @@ type ModalAddState = {
   error?: string | null
 };
 
-class ModalAddInternal extends React.Component<ModalAddInternalProps, ModalAddState> {
-  addLayer = () => {
-    if (this.props.layers.some(l => l.id === this.state.id)) {
-      this.setState({ error: this.props.t("Layer ID already exists") });
+type ModalAddSources = ModalAddInternalProps["sources"];
+
+function getLayersForSource(allSources: ModalAddSources, source: string) {
+  const sourceObj = allSources[source] || {};
+  return sourceObj.layers || [];
+}
+
+function getSources(allSources: ModalAddSources, type: LayerSpecification["type"]) {
+
+  switch(type) {
+    case "background":
+      return [];
+    case "hillshade":
+    case "color-relief":
+      return Object.entries(allSources).filter(([_, v]) => v.type === "raster-dem").map(([k, _]) => k);
+    case "raster":
+      return Object.entries(allSources).filter(([_, v]) => v.type === "raster").map(([k, _]) => k);
+    case "heatmap":
+    case "circle":
+    case "fill":
+    case "fill-extrusion":
+    case "line":
+    case "symbol":
+      return Object.entries(allSources).filter(([_, v]) => v.type === "vector" || v.type === "geojson").map(([k, _]) => k);
+    default:
+      return [];
+  }
+}
+
+const ModalAddInternal: React.FC<ModalAddInternalProps> = (props) => {
+  const [type, setType] = useState<LayerSpecification["type"]>("fill");
+  const [id, setId] = useState<string>("");
+  const [error, setError] = useState<string | null | undefined>(null);
+  const [source, setSource] = useState<string | undefined>(() => {
+    const sourceIds = Object.keys(props.sources);
+    return sourceIds.length > 0 ? sourceIds[0] : undefined;
+  });
+  const [sourceLayer, setSourceLayer] = useState<string | undefined>(() => {
+    const sourceIds = Object.keys(props.sources);
+    if (sourceIds.length === 0) return undefined;
+    const sourceLayers = props.sources[sourceIds[0]].layers || [];
+    return sourceLayers.length > 0 ? sourceLayers[0] : undefined;
+  });
+
+  // Mirrors `prevState.type` from the previous `componentDidUpdate`.
+  const prevType = useRef<LayerSpecification["type"]>(type);
+
+  useEffect(() => {
+    // Check if source is valid for new type
+    const oldType = prevType.current;
+    prevType.current = type;
+
+    // Only when the type has changed (also skips the initial mount)
+    if (oldType === type) return;
+
+    const availableSourcesOld = getSources(props.sources, oldType);
+    const availableSourcesNew = getSources(props.sources, type);
+
+    if(
+      source !== ""
+      // Was a valid source previously
+      && availableSourcesOld.indexOf(source!) > -1
+      // And is not a valid source now
+      && availableSourcesNew.indexOf(source!) < 0
+    ) {
+      // Clear the source
+      setSource("");
+    }
+  }, [type, source, props.sources]);
+
+  const addLayer = () => {
+    if (props.layers.some(l => l.id === id)) {
+      setError(props.t("Layer ID already exists"));
       return;
     }
 
-    const changedLayers = this.props.layers.slice(0);
+    const changedLayers = props.layers.slice(0);
     const layer: ModalAddState = {
-      id: this.state.id,
-      type: this.state.type,
+      id: id,
+      type: type,
     };
 
-    if(this.state.type !== "background") {
-      layer.source = this.state.source;
-      if(!NON_SOURCE_LAYERS.includes(this.state.type) && this.state["source-layer"]) {
-        layer["source-layer"] = this.state["source-layer"];
+    if(type !== "background") {
+      layer.source = source;
+      if(!NON_SOURCE_LAYERS.includes(type) && sourceLayer) {
+        layer["source-layer"] = sourceLayer;
       }
     }
 
     changedLayers.push(layer as LayerSpecification);
-    this.setState({ error: null }, () => {
-      this.props.onLayersChange(changedLayers);
-      this.props.onOpenToggle();
-    });
+    setError(null);
+    props.onLayersChange(changedLayers);
+    props.onOpenToggle();
   };
 
-  constructor(props: ModalAddInternalProps) {
-    super(props);
-    const state: ModalAddState = {
-      type: "fill",
-      id: "",
-      error: null,
-    };
-
-    if(Object.keys(props.sources).length > 0) {
-      state.source = Object.keys(this.props.sources)[0];
-      const sourceLayers = this.props.sources[state.source].layers || [];
-      if (sourceLayers.length > 0) {
-        state["source-layer"] = sourceLayers[0];
-      }
-    }
-    this.state = state;
+  const t = props.t;
+  const sources = getSources(props.sources, type);
+  const layers = getLayersForSource(props.sources, source!);
+  let errorElement;
+  if (error) {
+    errorElement = (
+      <div className="maputnik-modal-error">
+        {error}
+        <a
+          href="#"
+          onClick={() => setError(null)}
+          className="maputnik-modal-error-close"
+        >
+          ×
+        </a>
+      </div>
+    );
   }
 
-  componentDidUpdate(_prevProps: ModalAddInternalProps, prevState: ModalAddState) {
-    // Check if source is valid for new type
-    const oldType = prevState.type;
-    const newType = this.state.type;
-
-    const availableSourcesOld = this.getSources(oldType);
-    const availableSourcesNew = this.getSources(newType);
-
-    if(
-    // Type has changed
-      oldType !== newType
-      && prevState.source !== ""
-      // Was a valid source previously
-      && availableSourcesOld.indexOf(prevState.source!) > -1
-      // And is not a valid source now
-      && availableSourcesNew.indexOf(this.state.source!) < 0
-    ) {
-      // Clear the source
-      this.setState({
-        source: ""
-      });
-    }
-  }
-
-  getLayersForSource(source: string) {
-    const sourceObj = this.props.sources[source] || {};
-    return sourceObj.layers || [];
-  }
-
-  getSources(type: LayerSpecification["type"]) {
-
-    switch(type) {
-      case "background":
-        return [];
-      case "hillshade":
-      case "color-relief":
-        return Object.entries(this.props.sources).filter(([_, v]) => v.type === "raster-dem").map(([k, _]) => k);
-      case "raster":
-        return Object.entries(this.props.sources).filter(([_, v]) => v.type === "raster").map(([k, _]) => k);
-      case "heatmap":
-      case "circle":
-      case "fill":
-      case "fill-extrusion":
-      case "line":
-      case "symbol":
-        return Object.entries(this.props.sources).filter(([_, v]) => v.type === "vector" || v.type === "geojson").map(([k, _]) => k);
-      default:
-        return [];
-    }
-  }
-
-
-  render() {
-    const t = this.props.t;
-    const sources = this.getSources(this.state.type);
-    const layers = this.getLayersForSource(this.state.source!);
-    let errorElement;
-    if (this.state.error) {
-      errorElement = (
-        <div className="maputnik-modal-error">
-          {this.state.error}
-          <a
-            href="#"
-            onClick={() => this.setState({ error: null })}
-            className="maputnik-modal-error-close"
-          >
-            ×
-          </a>
-        </div>
-      );
-    }
-
-    return <Modal
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Add Layer")}
-      data-wd-key="modal:add-layer"
-      className="maputnik-add-modal"
-    >
-      {errorElement}
-      <div className="maputnik-add-layer">
-        <FieldId
-          value={this.state.id}
-          wdKey="add-layer.layer-id"
-          onChange={(v: string) => {
-            this.setState({ id: v, error: null });
-          }}
-        />
-        <FieldType
-          value={this.state.type}
-          wdKey="add-layer.layer-type"
-          onChange={(v: LayerSpecification["type"]) => this.setState({ type: v })}
-        />
-        {this.state.type !== "background" &&
+  return <Modal
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Add Layer")}
+    data-wd-key="modal:add-layer"
+    className="maputnik-add-modal"
+  >
+    {errorElement}
+    <div className="maputnik-add-layer">
+      <FieldId
+        value={id}
+        wdKey="add-layer.layer-id"
+        onChange={(v: string) => {
+          setId(v);
+          setError(null);
+        }}
+      />
+      <FieldType
+        value={type}
+        wdKey="add-layer.layer-type"
+        onChange={(v: LayerSpecification["type"]) => setType(v)}
+      />
+      {type !== "background" &&
       <FieldSource
         sourceIds={sources}
         wdKey="add-layer.layer-source-block"
-        value={this.state.source}
-        onChange={(v: string) => this.setState({ source: v })}
+        value={source}
+        onChange={(v: string) => setSource(v)}
       />
-        }
-        {!NON_SOURCE_LAYERS.includes(this.state.type) &&
+      }
+      {!NON_SOURCE_LAYERS.includes(type) &&
       <FieldSourceLayer
         sourceLayerIds={layers}
-        value={this.state["source-layer"]}
-        onChange={(v: string) => this.setState({ "source-layer": v })}
+        value={sourceLayer}
+        onChange={(v: string) => setSourceLayer(v)}
       />
-        }
-        <InputButton
-          className="maputnik-add-layer-button"
-          onClick={this.addLayer}
-          data-wd-key="add-layer"
-        >
-          {t("Add Layer")}
-        </InputButton>
-      </div>
-    </Modal>;
-  }
-}
+      }
+      <InputButton
+        className="maputnik-add-layer-button"
+        onClick={addLayer}
+        data-wd-key="add-layer"
+      >
+        {t("Add Layer")}
+      </InputButton>
+    </div>
+  </Modal>;
+};
 
 export const ModalAdd = withTranslation()(ModalAddInternal);

src/components/modals/ModalDebug.tsx

@@ -22,61 +22,59 @@ type ModalDebugInternalProps = {
 } & WithTranslation;
 
 
-class ModalDebugInternal extends React.Component<ModalDebugInternalProps> {
-  render() {
-    const {t, mapView} = this.props;
+const ModalDebugInternal: React.FC<ModalDebugInternalProps> = (props) => {
+  const {t, mapView} = props;
 
-    const osmZoom = Math.round(mapView.zoom)+1;
-    const osmLon = +(mapView.center.lng).toFixed(5);
-    const osmLat = +(mapView.center.lat).toFixed(5);
+  const osmZoom = Math.round(mapView.zoom)+1;
+  const osmLon = +(mapView.center.lng).toFixed(5);
+  const osmLat = +(mapView.center.lat).toFixed(5);
 
-    return <Modal
-      data-wd-key="modal:debug"
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Debug")}
-    >
-      <section className="maputnik-modal-section maputnik-modal-shortcuts">
-        <h1>{t("Options")}</h1>
-        {this.props.renderer === "mlgljs" &&
-          <ul>
-            {Object.entries(this.props.maplibreGlDebugOptions!).map(([key, val]) => {
-              return <li key={key}>
-                <label>
-                  <input type="checkbox" checked={val} onChange={(e) => this.props.onChangeMaplibreGlDebug(key, e.target.checked)} /> {key}
-                </label>
-              </li>;
-            })}
-          </ul>
-        }
-        {this.props.renderer === "ol" &&
-          <ul>
-            {Object.entries(this.props.openlayersDebugOptions!).map(([key, val]) => {
-              return <li key={key}>
-                <label>
-                  <input type="checkbox" checked={val} onChange={(e) => this.props.onChangeOpenlayersDebug(key, e.target.checked)} /> {key}
-                </label>
-              </li>;
-            })}
-          </ul>
-        }
-      </section>
-      <section className="maputnik-modal-section">
-        <h1>{t("Links")}</h1>
-        <p>
-          <Trans t={t}>
-            <a
-              target="_blank"
-              rel="noopener noreferrer"
-              href={`https://www.openstreetmap.org/#map=${osmZoom}/${osmLat}/${osmLon}`}
-            >
-              Open in OSM
-            </a>. Opens the current view on openstreetmap.org
-          </Trans>
-        </p>
-      </section>
-    </Modal>;
-  }
-}
+  return <Modal
+    data-wd-key="modal:debug"
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Debug")}
+  >
+    <section className="maputnik-modal-section maputnik-modal-shortcuts">
+      <h1>{t("Options")}</h1>
+      {props.renderer === "mlgljs" &&
+        <ul>
+          {Object.entries(props.maplibreGlDebugOptions!).map(([key, val]) => {
+            return <li key={key}>
+              <label>
+                <input type="checkbox" checked={val} onChange={(e) => props.onChangeMaplibreGlDebug(key, e.target.checked)} /> {key}
+              </label>
+            </li>;
+          })}
+        </ul>
+      }
+      {props.renderer === "ol" &&
+        <ul>
+          {Object.entries(props.openlayersDebugOptions!).map(([key, val]) => {
+            return <li key={key}>
+              <label>
+                <input type="checkbox" checked={val} onChange={(e) => props.onChangeOpenlayersDebug(key, e.target.checked)} /> {key}
+              </label>
+            </li>;
+          })}
+        </ul>
+      }
+    </section>
+    <section className="maputnik-modal-section">
+      <h1>{t("Links")}</h1>
+      <p>
+        <Trans t={t}>
+          <a
+            target="_blank"
+            rel="noopener noreferrer"
+            href={`https://www.openstreetmap.org/#map=${osmZoom}/${osmLat}/${osmLon}`}
+          >
+            Open in OSM
+          </a>. Opens the current view on openstreetmap.org
+        </Trans>
+      </p>
+    </section>
+  </Modal>;
+};
 
 export const ModalDebug = withTranslation()(ModalDebugInternal);

src/components/modals/ModalExport.tsx

@@ -28,31 +28,31 @@ type ModalExportInternalProps = {
 } & WithTranslation;
 
 
-class ModalExportInternal extends React.Component<ModalExportInternalProps> {
+const ModalExportInternal: React.FC<ModalExportInternalProps> = (props) => {
 
-  tokenizedStyle() {
+  function tokenizedStyle() {
     return format(
       stripAccessTokens(
-        replaceAccessTokens(this.props.mapStyle)
+        replaceAccessTokens(props.mapStyle)
       )
     );
   }
 
-  exportName() {
-    if (this.props.mapStyle.name) {
-      return Slugify(this.props.mapStyle.name, {
+  function exportName() {
+    if (props.mapStyle.name) {
+      return Slugify(props.mapStyle.name, {
         replacement: "_",
         remove: /[*\-+~.()'"!:]/g,
         lower: true
       });
     } else {
-      return this.props.mapStyle.id;
+      return props.mapStyle.id;
     }
   }
 
-  createHtml() {
-    const tokenStyle = this.tokenizedStyle();
-    const htmlTitle = this.props.mapStyle.name || this.props.t("Map");
+  function createHtml() {
+    const tokenStyle = tokenizedStyle();
+    const htmlTitle = props.mapStyle.name || props.t("Map");
     const html = `<!DOCTYPE html>
 <html>
 <head>
@@ -80,49 +80,11 @@ class ModalExportInternal extends React.Component<ModalExportInternalProps> {
 `;
 
     const blob = new Blob([html], {type: "text/html;charset=utf-8"});
-    const exportName = this.exportName();
-    saveAs(blob, exportName + ".html");
+    const name = exportName();
+    saveAs(blob, name + ".html");
   }
 
-  async saveStyle() {
-    const tokenStyle = this.tokenizedStyle();
-
-    // it is not guaranteed that the File System Access API is available on all
-    // browsers. If the function is not available, a fallback behavior is used.
-    if (!showSaveFilePickerAvailable) {
-      const blob = new Blob([tokenStyle], {type: "application/json;charset=utf-8"});
-      const exportName = this.exportName();
-      saveAs(blob, exportName + ".json");
-      return;
-    }
-
-    let fileHandle = this.props.fileHandle;
-    if (fileHandle == null) {
-      fileHandle = await this.createFileHandle();
-      this.props.onSetFileHandle(fileHandle);
-      if (fileHandle == null) return;
-    }
-
-    const writable = await fileHandle.createWritable();
-    await writable.write(tokenStyle);
-    await writable.close();
-    this.props.onOpenToggle();
-  }
-
-  async saveStyleAs() {
-    const tokenStyle = this.tokenizedStyle();
-
-    const fileHandle = await this.createFileHandle();
-    this.props.onSetFileHandle(fileHandle);
-    if (fileHandle == null) return;
-
-    const writable = await fileHandle.createWritable();
-    await writable.write(tokenStyle);
-    await writable.close();
-    this.props.onOpenToggle();
-  }
-
-  async createFileHandle(): Promise<FileSystemFileHandle | null> {
+  async function createFileHandle(): Promise<FileSystemFileHandle | null> {
     const pickerOpts: SaveFilePickerOptions = {
       types: [
         {
@@ -130,91 +92,126 @@ class ModalExportInternal extends React.Component<ModalExportInternalProps> {
           accept: {"application/json": [".json"]},
         },
       ],
-      suggestedName: this.exportName(),
+      suggestedName: exportName(),
     };
 
     const fileHandle = await window.showSaveFilePicker(pickerOpts) as FileSystemFileHandle;
-    this.props.onSetFileHandle(fileHandle);
+    props.onSetFileHandle(fileHandle);
     return fileHandle;
   }
 
-  changeMetadataProperty(property: string, value: any) {
+  async function saveStyle() {
+    const tokenStyle = tokenizedStyle();
+
+    // it is not guaranteed that the File System Access API is available on all
+    // browsers. If the function is not available, a fallback behavior is used.
+    if (!showSaveFilePickerAvailable) {
+      const blob = new Blob([tokenStyle], {type: "application/json;charset=utf-8"});
+      const name = exportName();
+      saveAs(blob, name + ".json");
+      return;
+    }
+
+    let fileHandle = props.fileHandle;
+    if (fileHandle == null) {
+      fileHandle = await createFileHandle();
+      props.onSetFileHandle(fileHandle);
+      if (fileHandle == null) return;
+    }
+
+    const writable = await fileHandle.createWritable();
+    await writable.write(tokenStyle);
+    await writable.close();
+    props.onOpenToggle();
+  }
+
+  async function saveStyleAs() {
+    const tokenStyle = tokenizedStyle();
+
+    const fileHandle = await createFileHandle();
+    props.onSetFileHandle(fileHandle);
+    if (fileHandle == null) return;
+
+    const writable = await fileHandle.createWritable();
+    await writable.write(tokenStyle);
+    await writable.close();
+    props.onOpenToggle();
+  }
+
+  function changeMetadataProperty(property: string, value: any) {
     const changedStyle = {
-      ...this.props.mapStyle,
+      ...props.mapStyle,
       metadata: {
-        ...this.props.mapStyle.metadata as any,
+        ...props.mapStyle.metadata as any,
         [property]: value
       }
     };
-    this.props.onStyleChanged(changedStyle);
+    props.onStyleChanged(changedStyle);
   }
 
+  const t = props.t;
+  const fsa = fieldSpecAdditional(t);
+  return <Modal
+    data-wd-key="modal:export"
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Save Style")}
+    className="maputnik-export-modal"
+  >
 
-  render() {
-    const t = this.props.t;
-    const fsa = fieldSpecAdditional(t);
-    return <Modal
-      data-wd-key="modal:export"
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Save Style")}
-      className="maputnik-export-modal"
-    >
+    <section className="maputnik-modal-section">
+      <h1>{t("Save Style")}</h1>
+      <p>
+        {t("Save the JSON style to your computer.")}
+      </p>
 
-      <section className="maputnik-modal-section">
-        <h1>{t("Save Style")}</h1>
-        <p>
-          {t("Save the JSON style to your computer.")}
-        </p>
+      <div>
+        <FieldString
+          label={fsa.maputnik.maptiler_access_token.label}
+          fieldSpec={fsa.maputnik.maptiler_access_token}
+          value={(props.mapStyle.metadata || {} as any)["maputnik:openmaptiles_access_token"]}
+          onChange={changeMetadataProperty.bind(null, "maputnik:openmaptiles_access_token")}
+        />
+        <FieldString
+          label={fsa.maputnik.thunderforest_access_token.label}
+          fieldSpec={fsa.maputnik.thunderforest_access_token}
+          value={(props.mapStyle.metadata || {} as any)["maputnik:thunderforest_access_token"]}
+          onChange={changeMetadataProperty.bind(null, "maputnik:thunderforest_access_token")}
+        />
+        <FieldString
+          label={fsa.maputnik.stadia_access_token.label}
+          fieldSpec={fsa.maputnik.stadia_access_token}
+          value={(props.mapStyle.metadata || {} as any)["maputnik:stadia_access_token"]}
+          onChange={changeMetadataProperty.bind(null, "maputnik:stadia_access_token")}
+        />
+        <FieldString
+          label={fsa.maputnik.locationiq_access_token.label}
+          fieldSpec={fsa.maputnik.locationiq_access_token}
+          value={(props.mapStyle.metadata || {} as any)["maputnik:locationiq_access_token"]}
+          onChange={changeMetadataProperty.bind(null, "maputnik:locationiq_access_token")}
+        />
+      </div>
 
-        <div>
-          <FieldString
-            label={fsa.maputnik.maptiler_access_token.label}
-            fieldSpec={fsa.maputnik.maptiler_access_token}
-            value={(this.props.mapStyle.metadata || {} as any)["maputnik:openmaptiles_access_token"]}
-            onChange={this.changeMetadataProperty.bind(this, "maputnik:openmaptiles_access_token")}
-          />
-          <FieldString
-            label={fsa.maputnik.thunderforest_access_token.label}
-            fieldSpec={fsa.maputnik.thunderforest_access_token}
-            value={(this.props.mapStyle.metadata || {} as any)["maputnik:thunderforest_access_token"]}
-            onChange={this.changeMetadataProperty.bind(this, "maputnik:thunderforest_access_token")}
-          />
-          <FieldString
-            label={fsa.maputnik.stadia_access_token.label}
-            fieldSpec={fsa.maputnik.stadia_access_token}
-            value={(this.props.mapStyle.metadata || {} as any)["maputnik:stadia_access_token"]}
-            onChange={this.changeMetadataProperty.bind(this, "maputnik:stadia_access_token")}
-          />
-          <FieldString
-            label={fsa.maputnik.locationiq_access_token.label}
-            fieldSpec={fsa.maputnik.locationiq_access_token}
-            value={(this.props.mapStyle.metadata || {} as any)["maputnik:locationiq_access_token"]}
-            onChange={this.changeMetadataProperty.bind(this, "maputnik:locationiq_access_token")}
-          />
-        </div>
-
-        <div className="maputnik-modal-export-buttons">
-          <InputButton onClick={this.saveStyle.bind(this)}>
+      <div className="maputnik-modal-export-buttons">
+        <InputButton onClick={saveStyle}>
+          <MdSave/>
+          {t("Save")}
+        </InputButton>
+        {showSaveFilePickerAvailable && (
+          <InputButton onClick={saveStyleAs}>
             <MdSave/>
-            {t("Save")}
+            {t("Save as")}
           </InputButton>
-          {showSaveFilePickerAvailable && (
-            <InputButton onClick={this.saveStyleAs.bind(this)}>
-              <MdSave/>
-              {t("Save as")}
-            </InputButton>
-          )}
+        )}
 
-          <InputButton onClick={this.createHtml.bind(this)}>
-            <MdMap/>
-            {t("Create HTML")}
-          </InputButton>
-        </div>
-      </section>
+        <InputButton onClick={createHtml}>
+          <MdMap/>
+          {t("Create HTML")}
+        </InputButton>
+      </div>
+    </section>
 
-    </Modal>;
-  }
-}
+  </Modal>;
+};
 
 export const ModalExport = withTranslation()(ModalExportInternal);

src/components/modals/ModalLoading.tsx

@@ -13,26 +13,24 @@ type ModalLoadingInternalProps = {
 } & WithTranslation;
 
 
-class ModalLoadingInternal extends React.Component<ModalLoadingInternalProps> {
-  render() {
-    const t = this.props.t;
-    return <Modal
-      data-wd-key="modal:loading"
-      isOpen={this.props.isOpen}
-      underlayClickExits={false}
-      title={this.props.title}
-      onOpenToggle={() => this.props.onCancel()}
-    >
-      <p>
-        {this.props.message}
-      </p>
-      <p className="maputnik-dialog__buttons">
-        <InputButton onClick={(e) => this.props.onCancel(e)}>
-          {t("Cancel")}
-        </InputButton>
-      </p>
-    </Modal>;
-  }
-}
+const ModalLoadingInternal: React.FC<ModalLoadingInternalProps> = (props) => {
+  const t = props.t;
+  return <Modal
+    data-wd-key="modal:loading"
+    isOpen={props.isOpen}
+    underlayClickExits={false}
+    title={props.title}
+    onOpenToggle={() => props.onCancel()}
+  >
+    <p>
+      {props.message}
+    </p>
+    <p className="maputnik-dialog__buttons">
+      <InputButton onClick={(e) => props.onCancel(e)}>
+        {t("Cancel")}
+      </InputButton>
+    </p>
+  </Modal>;
+};
 
 export const ModalLoading = withTranslation()(ModalLoadingInternal);

src/components/modals/ModalOpen.tsx

@@ -1,4 +1,4 @@
-import React, { type DragEvent, type FormEvent } from "react";
+import React, { type DragEvent, type FormEvent, useRef, useState } from "react";
 import { MdFileUpload } from "react-icons/md";
 import { MdAddCircleOutline } from "react-icons/md";
 import { Trans, type WithTranslation, withTranslation } from "react-i18next";
@@ -18,29 +18,27 @@ type PublicStyleProps = {
   onSelect(...args: unknown[]): unknown
 };
 
-class PublicStyle extends React.Component<PublicStyleProps> {
-  render() {
-    return <div className="maputnik-public-style">
-      <InputButton
-        className="maputnik-public-style-button"
-        aria-label={this.props.title}
-        onClick={() => this.props.onSelect(this.props.url)}
-      >
-        <div className="maputnik-public-style-header">
-          <div>{this.props.title}</div>
-          <span className="maputnik-space" />
-          <MdAddCircleOutline />
-        </div>
-        <div
-          className="maputnik-public-style-thumbnail"
-          style={{
-            backgroundImage: `url(${this.props.thumbnailUrl})`
-          }}
-        ></div>
-      </InputButton>
-    </div>;
-  }
-}
+const PublicStyle: React.FC<PublicStyleProps> = (props) => {
+  return <div className="maputnik-public-style">
+    <InputButton
+      className="maputnik-public-style-button"
+      aria-label={props.title}
+      onClick={() => props.onSelect(props.url)}
+    >
+      <div className="maputnik-public-style-header">
+        <div>{props.title}</div>
+        <span className="maputnik-space" />
+        <MdAddCircleOutline />
+      </div>
+      <div
+        className="maputnik-public-style-thumbnail"
+        style={{
+          backgroundImage: `url(${props.thumbnailUrl})`
+        }}
+      ></div>
+    </InputButton>
+  </div>;
+};
 
 type ModalOpenInternalProps = {
   isOpen: boolean
@@ -49,46 +47,32 @@ type ModalOpenInternalProps = {
   fileHandle: FileSystemFileHandle | null
 } & WithTranslation;
 
-type ModalOpenState = {
-  styleUrl: string
-  isDragOver: boolean
-  error?: string | null
-  activeRequest?: any
-  activeRequestUrl?: string | null
-};
+const ModalOpenInternal: React.FC<ModalOpenInternalProps> = (props) => {
+  const fileInputRef = useRef<HTMLInputElement>(null);
 
-class ModalOpenInternal extends React.Component<ModalOpenInternalProps, ModalOpenState> {
-  private fileInputRef = React.createRef<HTMLInputElement>();
+  const [styleUrl, setStyleUrl] = useState<string>("");
+  const [isDragOver, setIsDragOver] = useState<boolean>(false);
+  const [error, setError] = useState<string | null | undefined>(undefined);
+  const [activeRequest, setActiveRequest] = useState<any>(undefined);
+  const [activeRequestUrl, setActiveRequestUrl] = useState<string | null | undefined>(undefined);
 
-  constructor(props: ModalOpenInternalProps) {
-    super(props);
-    this.state = {
-      styleUrl: "",
-      isDragOver: false,
-    };
-  }
+  const clearError = () => {
+    setError(null);
+  };
 
-  clearError() {
-    this.setState({
-      error: null
-    });
-  }
-
-  onCancelActiveRequest(e: Event) {
+  const onCancelActiveRequest = (e: Event) => {
     // Else the click propagates to the underlying modal
     if (e) e.stopPropagation();
 
-    if (this.state.activeRequest) {
-      this.state.activeRequest.abort();
-      this.setState({
-        activeRequest: null,
-        activeRequestUrl: null
-      });
+    if (activeRequest) {
+      activeRequest.abort();
+      setActiveRequest(null);
+      setActiveRequestUrl(null);
     }
-  }
+  };
 
-  onStyleSelect = (styleUrl: string) => {
-    this.clearError();
+  const onStyleSelect = (styleUrl: string) => {
+    clearError();
 
     let canceled: boolean = false;
 
@@ -104,43 +88,37 @@ class ModalOpenInternal extends React.Component<ModalOpenInternalProps, ModalOpe
           return;
         }
 
-        this.setState({
-          activeRequest: null,
-          activeRequestUrl: null
-        });
+        setActiveRequest(null);
+        setActiveRequestUrl(null);
 
         const mapStyle = ensureStyleValidity(body);
         console.log("Loaded style ", mapStyle.id);
-        this.props.onStyleOpen(mapStyle);
-        this.onOpenToggle();
+        props.onStyleOpen(mapStyle);
+        onOpenToggle();
       })
       .catch((err) => {
-        this.setState({
-          error: `Failed to load: '${styleUrl}'`,
-          activeRequest: null,
-          activeRequestUrl: null
-        });
+        setError(`Failed to load: '${styleUrl}'`);
+        setActiveRequest(null);
+        setActiveRequestUrl(null);
         console.error(err);
         console.warn("Could not open the style URL", styleUrl);
       });
 
-    this.setState({
-      activeRequest: {
-        abort: function () {
-          canceled = true;
-        }
-      },
-      activeRequestUrl: styleUrl
+    setActiveRequest({
+      abort: function () {
+        canceled = true;
+      }
     });
+    setActiveRequestUrl(styleUrl);
   };
 
-  onSubmitUrl = (e: FormEvent<HTMLFormElement>) => {
+  const onSubmitUrl = (e: FormEvent<HTMLFormElement>) => {
     e.preventDefault();
-    this.onStyleSelect(this.state.styleUrl);
+    onStyleSelect(styleUrl);
   };
 
-  onOpenFile = async () => {
-    this.clearError();
+  const onOpenFile = async () => {
+    clearError();
 
     const pickerOpts: OpenFilePickerOptions = {
       types: [
@@ -160,26 +138,24 @@ class ModalOpenInternal extends React.Component<ModalOpenInternalProps, ModalOpe
     try {
       mapStyle = JSON.parse(content);
     } catch (err) {
-      this.setState({
-        error: (err as Error).toString()
-      });
+      setError((err as Error).toString());
       return;
     }
     mapStyle = ensureStyleValidity(mapStyle);
 
-    this.props.onStyleOpen(mapStyle, fileHandle);
-    this.onOpenToggle();
+    props.onStyleOpen(mapStyle, fileHandle);
+    onOpenToggle();
     return file;
   };
 
   // it is not guaranteed that the File System Access API is available on all
   // browsers. If the function is not available, a fallback behavior is used.
-  onFileChanged = (files: FileList | null) => {
+  const onFileChanged = (files: FileList | null) => {
     if (!files) return;
     if (files.length === 0) return;
     const file = files[0];
     const reader = new FileReader();
-    this.clearError();
+    clearError();
 
     reader.readAsText(file, "UTF-8");
     reader.onload = e => {
@@ -188,180 +164,172 @@ class ModalOpenInternal extends React.Component<ModalOpenInternalProps, ModalOpe
         mapStyle = JSON.parse(e.target?.result as string);
       }
       catch (err) {
-        this.setState({
-          error: (err as Error).toString()
-        });
+        setError((err as Error).toString());
         return;
       }
       mapStyle = ensureStyleValidity(mapStyle);
-      this.props.onStyleOpen(mapStyle);
-      this.onOpenToggle();
+      props.onStyleOpen(mapStyle);
+      onOpenToggle();
     };
     reader.onerror = e => console.log(e.target);
   };
 
-  onOpenToggle() {
-    this.setState({
-      styleUrl: "",
-      isDragOver: false,
-    });
-    this.clearError();
-    this.props.onOpenToggle();
-  }
+  const onOpenToggle = () => {
+    setStyleUrl("");
+    setIsDragOver(false);
+    clearError();
+    props.onOpenToggle();
+  };
 
-  onBrowseClick = async () => {
+  const onBrowseClick = async () => {
     if (typeof window.showOpenFilePicker === "function") {
-      await this.onOpenFile();
+      await onOpenFile();
       return;
     }
 
-    this.fileInputRef.current?.click();
+    fileInputRef.current?.click();
   };
 
-  onFileDragOver = (e: DragEvent<HTMLDivElement>) => {
+  const onFileDragOver = (e: DragEvent<HTMLDivElement>) => {
     e.preventDefault();
     e.stopPropagation();
 
-    if (!this.state.isDragOver) {
-      this.setState({ isDragOver: true });
+    if (!isDragOver) {
+      setIsDragOver(true);
     }
   };
 
-  onFileDragLeave = (e: DragEvent<HTMLDivElement>) => {
+  const onFileDragLeave = (e: DragEvent<HTMLDivElement>) => {
     e.preventDefault();
     e.stopPropagation();
-    this.setState({ isDragOver: false });
+    setIsDragOver(false);
   };
 
-  onFileDrop = (e: DragEvent<HTMLDivElement>) => {
+  const onFileDrop = (e: DragEvent<HTMLDivElement>) => {
     e.preventDefault();
     e.stopPropagation();
 
-    this.setState({ isDragOver: false });
-    this.onFileChanged(e.dataTransfer.files);
+    setIsDragOver(false);
+    onFileChanged(e.dataTransfer.files);
   };
 
-  onChangeUrl = (url: string) => {
-    this.setState({
-      styleUrl: url,
-    });
+  const onChangeUrl = (url: string) => {
+    setStyleUrl(url);
   };
 
-  render() {
-    const t = this.props.t;
-    const styleOptions = publicStyles.map(style => {
-      return <PublicStyle
-        key={style.id}
-        url={style.url}
-        title={style.title}
-        thumbnailUrl={style.thumbnail}
-        onSelect={this.onStyleSelect}
-      />;
-    });
+  const t = props.t;
+  const styleOptions = publicStyles.map(style => {
+    return <PublicStyle
+      key={style.id}
+      url={style.url}
+      title={style.title}
+      thumbnailUrl={style.thumbnail}
+      onSelect={onStyleSelect}
+    />;
+  });
 
-    let errorElement;
-    if (this.state.error) {
-      errorElement = (
-        <div className="maputnik-modal-error">
-          {this.state.error}
-          <a href="#" onClick={() => this.clearError()} className="maputnik-modal-error-close">×</a>
-        </div>
-      );
-    }
-
-    return (
-      <div>
-        <Modal
-          data-wd-key="modal:open"
-          isOpen={this.props.isOpen}
-          onOpenToggle={() => this.onOpenToggle()}
-          title={t("Open Style")}
-        >
-          {errorElement}
-          <section className="maputnik-modal-section">
-            <h1>{t("Open local Style")}</h1>
-            <p>{t("Open a local JSON style from your computer.")}</p>
-            <div
-              data-wd-key="modal:open.dropzone"
-              className={`maputnik-upload-dropzone${this.state.isDragOver ? " maputnik-upload-dropzone--active" : ""}`}
-              role="button"
-              tabIndex={0}
-              onDragOver={this.onFileDragOver}
-              onDragLeave={this.onFileDragLeave}
-              onDrop={this.onFileDrop}
-              onClick={() => void this.onBrowseClick()}
-              onKeyDown={(e) => {
-                if (e.key === "Enter" || e.key === " ") {
-                  e.preventDefault();
-                  void this.onBrowseClick();
-                }
-              }}
-            >
-              <div className="maputnik-upload-dropzone-content">
-                <MdFileUpload className="maputnik-upload-dropzone-icon" aria-hidden="true" />
-                <p className="maputnik-upload-dropzone-text">
-                  {t("Drag and drop a style JSON file here or click to browse")}
-                </p>
-              </div>
-              <input
-                ref={this.fileInputRef}
-                data-wd-key="modal:open.file.input"
-                type="file"
-                style={{ display: "none" }}
-                onChange={(e) => this.onFileChanged(e.target.files)}
-              />
-            </div>
-          </section>
-
-          <section className="maputnik-modal-section">
-            <form onSubmit={this.onSubmitUrl}>
-              <h1>{t("Load from URL")}</h1>
-              <p>
-                <Trans t={t}>
-                  Load from a URL. Note that the URL must have <a href="https://enable-cors.org" target="_blank" rel="noopener noreferrer">CORS enabled</a>.
-                </Trans>
-              </p>
-              <InputUrl
-                aria-label={t("Style URL")}
-                data-wd-key="modal:open.url.input"
-                type="text"
-                className="maputnik-input"
-                default={t("Enter URL...")}
-                value={this.state.styleUrl}
-                onInput={this.onChangeUrl}
-                onChange={this.onChangeUrl}
-              />
-              <div>
-                <InputButton
-                  data-wd-key="modal:open.url.button"
-                  type="submit"
-                  className="maputnik-big-button"
-                  disabled={this.state.styleUrl.length < 1}
-                >Load from URL</InputButton>
-              </div>
-            </form>
-          </section>
-
-          <section className="maputnik-modal-section maputnik-modal-section--shrink">
-            <h1>{t("Gallery Styles")}</h1>
-            <p>
-              {t("Open one of the publicly available styles to start from.")}
-            </p>
-            <div className="maputnik-style-gallery-container">
-              {styleOptions}
-            </div>
-          </section>
-        </Modal>
-
-        <ModalLoading
-          isOpen={!!this.state.activeRequest}
-          title={t("Loading style")}
-          onCancel={(e: Event) => this.onCancelActiveRequest(e)}
-          message={t("Loading") + ": " + this.state.activeRequestUrl}
-        />
+  let errorElement;
+  if (error) {
+    errorElement = (
+      <div className="maputnik-modal-error">
+        {error}
+        <a href="#" onClick={() => clearError()} className="maputnik-modal-error-close">×</a>
       </div>
     );
   }
-}
+
+  return (
+    <div>
+      <Modal
+        data-wd-key="modal:open"
+        isOpen={props.isOpen}
+        onOpenToggle={() => onOpenToggle()}
+        title={t("Open Style")}
+      >
+        {errorElement}
+        <section className="maputnik-modal-section">
+          <h1>{t("Open local Style")}</h1>
+          <p>{t("Open a local JSON style from your computer.")}</p>
+          <div
+            data-wd-key="modal:open.dropzone"
+            className={`maputnik-upload-dropzone${isDragOver ? " maputnik-upload-dropzone--active" : ""}`}
+            role="button"
+            tabIndex={0}
+            onDragOver={onFileDragOver}
+            onDragLeave={onFileDragLeave}
+            onDrop={onFileDrop}
+            onClick={() => void onBrowseClick()}
+            onKeyDown={(e) => {
+              if (e.key === "Enter" || e.key === " ") {
+                e.preventDefault();
+                void onBrowseClick();
+              }
+            }}
+          >
+            <div className="maputnik-upload-dropzone-content">
+              <MdFileUpload className="maputnik-upload-dropzone-icon" aria-hidden="true" />
+              <p className="maputnik-upload-dropzone-text">
+                {t("Drag and drop a style JSON file here or click to browse")}
+              </p>
+            </div>
+            <input
+              ref={fileInputRef}
+              data-wd-key="modal:open.file.input"
+              type="file"
+              style={{ display: "none" }}
+              onChange={(e) => onFileChanged(e.target.files)}
+            />
+          </div>
+        </section>
+
+        <section className="maputnik-modal-section">
+          <form onSubmit={onSubmitUrl}>
+            <h1>{t("Load from URL")}</h1>
+            <p>
+              <Trans t={t}>
+                Load from a URL. Note that the URL must have <a href="https://enable-cors.org" target="_blank" rel="noopener noreferrer">CORS enabled</a>.
+              </Trans>
+            </p>
+            <InputUrl
+              aria-label={t("Style URL")}
+              data-wd-key="modal:open.url.input"
+              type="text"
+              className="maputnik-input"
+              default={t("Enter URL...")}
+              value={styleUrl}
+              onInput={onChangeUrl}
+              onChange={onChangeUrl}
+            />
+            <div>
+              <InputButton
+                data-wd-key="modal:open.url.button"
+                type="submit"
+                className="maputnik-big-button"
+                disabled={styleUrl.length < 1}
+              >Load from URL</InputButton>
+            </div>
+          </form>
+        </section>
+
+        <section className="maputnik-modal-section maputnik-modal-section--shrink">
+          <h1>{t("Gallery Styles")}</h1>
+          <p>
+            {t("Open one of the publicly available styles to start from.")}
+          </p>
+          <div className="maputnik-style-gallery-container">
+            {styleOptions}
+          </div>
+        </section>
+      </Modal>
+
+      <ModalLoading
+        isOpen={!!activeRequest}
+        title={t("Loading style")}
+        onCancel={(e: Event) => onCancelActiveRequest(e)}
+        message={t("Loading") + ": " + activeRequestUrl}
+      />
+    </div>
+  );
+};
 
 export const ModalOpen = withTranslation()(ModalOpenInternal);

src/components/modals/ModalSettings.tsx

@@ -24,10 +24,10 @@ type ModalSettingsInternalProps = {
   onOpenToggle(): void
 } & WithTranslation;
 
-class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps> {
-  changeTransitionProperty(property: keyof TransitionSpecification, value: number | undefined) {
+const ModalSettingsInternal: React.FC<ModalSettingsInternalProps> = (props) => {
+  function changeTransitionProperty(property: keyof TransitionSpecification, value: number | undefined) {
     const transition = {
-      ...this.props.mapStyle.transition,
+      ...props.mapStyle.transition,
     };
 
     if (value === undefined) {
@@ -37,15 +37,15 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
       transition[property] = value;
     }
 
-    this.props.onStyleChanged({
-      ...this.props.mapStyle,
+    props.onStyleChanged({
+      ...props.mapStyle,
       transition,
     });
   }
 
-  changeLightProperty(property: keyof LightSpecification, value: any) {
+  function changeLightProperty(property: keyof LightSpecification, value: any) {
     const light = {
-      ...this.props.mapStyle.light,
+      ...props.mapStyle.light,
     };
 
     if (value === undefined) {
@@ -56,15 +56,15 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
       light[property] = value;
     }
 
-    this.props.onStyleChanged({
-      ...this.props.mapStyle,
+    props.onStyleChanged({
+      ...props.mapStyle,
       light,
     });
   }
 
-  changeTerrainProperty(property: keyof TerrainSpecification, value: any) {
+  function changeTerrainProperty(property: keyof TerrainSpecification, value: any) {
     const terrain = {
-      ...this.props.mapStyle.terrain,
+      ...props.mapStyle.terrain,
     } as TerrainSpecification;
 
     if (value === undefined) {
@@ -75,15 +75,15 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
       terrain[property] = value;
     }
 
-    this.props.onStyleChanged({
-      ...this.props.mapStyle,
+    props.onStyleChanged({
+      ...props.mapStyle,
       terrain,
     });
   }
 
-  changeProjectionType(value: any) {
+  function changeProjectionType(value: any) {
     const projection = {
-      ...this.props.mapStyle.projection,
+      ...props.mapStyle.projection,
     } as ProjectionSpecification;
 
     if (value === undefined) {
@@ -93,15 +93,15 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
       projection.type = value;
     }
 
-    this.props.onStyleChanged({
-      ...this.props.mapStyle,
+    props.onStyleChanged({
+      ...props.mapStyle,
       projection,
     });
   }
 
-  changeStyleProperty(property: keyof StyleSpecification | "owner", value: any) {
+  function changeStyleProperty(property: keyof StyleSpecification | "owner", value: any) {
     const changedStyle = {
-      ...this.props.mapStyle,
+      ...props.mapStyle,
     };
 
     if (value === undefined) {
@@ -112,224 +112,222 @@ class ModalSettingsInternal extends React.Component<ModalSettingsInternalProps>
       // @ts-ignore
       changedStyle[property] = value;
     }
-    this.props.onStyleChanged(changedStyle);
+    props.onStyleChanged(changedStyle);
   }
 
-  render() {
-    const metadata = this.props.mapStyle.metadata || {} as any;
-    const {t, onChangeMetadataProperty, mapStyle} = this.props;
-    const fsa = fieldSpecAdditional(t);
+  const metadata = props.mapStyle.metadata || {} as any;
+  const {t, onChangeMetadataProperty, mapStyle} = props;
+  const fsa = fieldSpecAdditional(t);
 
-    const light = this.props.mapStyle.light || {};
-    const transition = this.props.mapStyle.transition || {};
-    const terrain = this.props.mapStyle.terrain || {} as TerrainSpecification;
-    const projection = this.props.mapStyle.projection || {} as ProjectionSpecification;
+  const light = props.mapStyle.light || {};
+  const transition = props.mapStyle.transition || {};
+  const terrain = props.mapStyle.terrain || {} as TerrainSpecification;
+  const projection = props.mapStyle.projection || {} as ProjectionSpecification;
 
-    return <Modal
-      data-wd-key="modal:settings"
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Style Settings")}
-    >
-      <div className="modal:settings">
-        <FieldString
-          label={t("Name")}
-          fieldSpec={latest.$root.name}
-          data-wd-key="modal:settings.name"
-          value={this.props.mapStyle.name}
-          onChange={(value) => this.changeStyleProperty("name", value)}
+  return <Modal
+    data-wd-key="modal:settings"
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Style Settings")}
+  >
+    <div className="modal:settings">
+      <FieldString
+        label={t("Name")}
+        fieldSpec={latest.$root.name}
+        data-wd-key="modal:settings.name"
+        value={props.mapStyle.name}
+        onChange={(value) => changeStyleProperty("name", value)}
+      />
+      <FieldString
+        label={t("Owner")}
+        fieldSpec={{doc: t("Owner ID of the style. Used by Mapbox or future style APIs.")}}
+        data-wd-key="modal:settings.owner"
+        value={(props.mapStyle as any).owner}
+        onChange={(value) => changeStyleProperty("owner", value)}
+      />
+      <Block label={t("Sprite URL")} fieldSpec={latest.$root.sprite} data-wd-key="modal:settings.sprite">
+        <FieldJson
+          lintType="json"
+          value={props.mapStyle.sprite as any}
+          onChange={(value) => changeStyleProperty("sprite", value)}
         />
-        <FieldString
-          label={t("Owner")}
-          fieldSpec={{doc: t("Owner ID of the style. Used by Mapbox or future style APIs.")}}
-          data-wd-key="modal:settings.owner"
-          value={(this.props.mapStyle as any).owner}
-          onChange={(value) => this.changeStyleProperty("owner", value)}
-        />
-        <Block label={t("Sprite URL")} fieldSpec={latest.$root.sprite} data-wd-key="modal:settings.sprite">
-          <FieldJson
-            lintType="json"
-            value={this.props.mapStyle.sprite as any}
-            onChange={(value) => this.changeStyleProperty("sprite", value)}
-          />
-        </Block>
+      </Block>
 
-        <FieldUrl
-          label={t("Glyphs URL")}
-          fieldSpec={latest.$root.glyphs}
-          data-wd-key="modal:settings.glyphs"
-          value={this.props.mapStyle.glyphs as string}
-          onChange={(value) => this.changeStyleProperty("glyphs", value)}
-        />
+      <FieldUrl
+        label={t("Glyphs URL")}
+        fieldSpec={latest.$root.glyphs}
+        data-wd-key="modal:settings.glyphs"
+        value={props.mapStyle.glyphs as string}
+        onChange={(value) => changeStyleProperty("glyphs", value)}
+      />
 
-        <FieldString
-          label={fsa.maputnik.maptiler_access_token.label}
-          fieldSpec={fsa.maputnik.maptiler_access_token}
-          data-wd-key="modal:settings.maputnik:openmaptiles_access_token"
-          value={metadata["maputnik:openmaptiles_access_token"]}
-          onChange={(value) => onChangeMetadataProperty("maputnik:openmaptiles_access_token", value)}
-        />
+      <FieldString
+        label={fsa.maputnik.maptiler_access_token.label}
+        fieldSpec={fsa.maputnik.maptiler_access_token}
+        data-wd-key="modal:settings.maputnik:openmaptiles_access_token"
+        value={metadata["maputnik:openmaptiles_access_token"]}
+        onChange={(value) => onChangeMetadataProperty("maputnik:openmaptiles_access_token", value)}
+      />
 
-        <FieldString
-          label={fsa.maputnik.thunderforest_access_token.label}
-          fieldSpec={fsa.maputnik.thunderforest_access_token}
-          data-wd-key="modal:settings.maputnik:thunderforest_access_token"
-          value={metadata["maputnik:thunderforest_access_token"]}
-          onChange={(value) => onChangeMetadataProperty("maputnik:thunderforest_access_token", value)}
-        />
+      <FieldString
+        label={fsa.maputnik.thunderforest_access_token.label}
+        fieldSpec={fsa.maputnik.thunderforest_access_token}
+        data-wd-key="modal:settings.maputnik:thunderforest_access_token"
+        value={metadata["maputnik:thunderforest_access_token"]}
+        onChange={(value) => onChangeMetadataProperty("maputnik:thunderforest_access_token", value)}
+      />
 
-        <FieldString
-          label={fsa.maputnik.stadia_access_token.label}
-          fieldSpec={fsa.maputnik.stadia_access_token}
-          data-wd-key="modal:settings.maputnik:stadia_access_token"
-          value={metadata["maputnik:stadia_access_token"]}
-          onChange={(value) => onChangeMetadataProperty("maputnik:stadia_access_token", value)}
-        />
+      <FieldString
+        label={fsa.maputnik.stadia_access_token.label}
+        fieldSpec={fsa.maputnik.stadia_access_token}
+        data-wd-key="modal:settings.maputnik:stadia_access_token"
+        value={metadata["maputnik:stadia_access_token"]}
+        onChange={(value) => onChangeMetadataProperty("maputnik:stadia_access_token", value)}
+      />
 
-        <FieldString
-          label={fsa.maputnik.locationiq_access_token.label}
-          fieldSpec={fsa.maputnik.locationiq_access_token}
-          data-wd-key="modal:settings.maputnik:locationiq_access_token"
-          value={metadata["maputnik:locationiq_access_token"]}
-          onChange={(value) => onChangeMetadataProperty("maputnik:locationiq_access_token", value)}
-        />
+      <FieldString
+        label={fsa.maputnik.locationiq_access_token.label}
+        fieldSpec={fsa.maputnik.locationiq_access_token}
+        data-wd-key="modal:settings.maputnik:locationiq_access_token"
+        value={metadata["maputnik:locationiq_access_token"]}
+        onChange={(value) => onChangeMetadataProperty("maputnik:locationiq_access_token", value)}
+      />
 
-        <FieldArray
-          label={t("Center")}
-          fieldSpec={latest.$root.center}
-          length={2}
-          type="number"
-          value={mapStyle.center || []}
-          default={[0, 0]}
-          onChange={(value) => this.changeStyleProperty("center", value)}
-        />
+      <FieldArray
+        label={t("Center")}
+        fieldSpec={latest.$root.center}
+        length={2}
+        type="number"
+        value={mapStyle.center || []}
+        default={[0, 0]}
+        onChange={(value) => changeStyleProperty("center", value)}
+      />
 
-        <FieldNumber
-          label={t("Zoom")}
-          data-wd-key="modal:settings.zoom"
-          fieldSpec={latest.$root.zoom}
-          value={mapStyle.zoom}
-          default={0}
-          onChange={(value) => this.changeStyleProperty("zoom", value)}
-        />
+      <FieldNumber
+        label={t("Zoom")}
+        data-wd-key="modal:settings.zoom"
+        fieldSpec={latest.$root.zoom}
+        value={mapStyle.zoom}
+        default={0}
+        onChange={(value) => changeStyleProperty("zoom", value)}
+      />
 
-        <FieldNumber
-          label={t("Bearing")}
-          data-wd-key="modal:settings.bearing"
-          fieldSpec={latest.$root.bearing}
-          value={mapStyle.bearing}
-          default={latest.$root.bearing.default}
-          onChange={(value) => this.changeStyleProperty("bearing", value)}
-        />
+      <FieldNumber
+        label={t("Bearing")}
+        data-wd-key="modal:settings.bearing"
+        fieldSpec={latest.$root.bearing}
+        value={mapStyle.bearing}
+        default={latest.$root.bearing.default}
+        onChange={(value) => changeStyleProperty("bearing", value)}
+      />
 
-        <FieldNumber
-          label={t("Pitch")}
-          data-wd-key="modal:settings.pitch"
-          fieldSpec={latest.$root.pitch}
-          value={mapStyle.pitch}
-          default={latest.$root.pitch.default}
-          onChange={(value) => this.changeStyleProperty("pitch", value)}
-        />
+      <FieldNumber
+        label={t("Pitch")}
+        data-wd-key="modal:settings.pitch"
+        fieldSpec={latest.$root.pitch}
+        value={mapStyle.pitch}
+        default={latest.$root.pitch.default}
+        onChange={(value) => changeStyleProperty("pitch", value)}
+      />
 
-        <FieldEnum
-          label={t("Light anchor")}
-          fieldSpec={latest.light.anchor}
-          name="light-anchor"
-          value={light.anchor as string}
-          options={Object.keys(latest.light.anchor.values)}
-          default={latest.light.anchor.default}
-          onChange={(value) => this.changeLightProperty("anchor", value)}
-        />
+      <FieldEnum
+        label={t("Light anchor")}
+        fieldSpec={latest.light.anchor}
+        name="light-anchor"
+        value={light.anchor as string}
+        options={Object.keys(latest.light.anchor.values)}
+        default={latest.light.anchor.default}
+        onChange={(value) => changeLightProperty("anchor", value)}
+      />
 
-        <FieldColor
-          label={t("Light color")}
-          fieldSpec={latest.light.color}
-          value={light.color as string}
-          default={latest.light.color.default}
-          onChange={(value) => this.changeLightProperty("color", value)}
-        />
+      <FieldColor
+        label={t("Light color")}
+        fieldSpec={latest.light.color}
+        value={light.color as string}
+        default={latest.light.color.default}
+        onChange={(value) => changeLightProperty("color", value)}
+      />
 
-        <FieldNumber
-          label={t("Light intensity")}
-          data-wd-key="modal:settings.light-intensity"
-          fieldSpec={latest.light.intensity}
-          value={light.intensity as number}
-          default={latest.light.intensity.default}
-          onChange={(value) => this.changeLightProperty("intensity", value)}
-        />
+      <FieldNumber
+        label={t("Light intensity")}
+        data-wd-key="modal:settings.light-intensity"
+        fieldSpec={latest.light.intensity}
+        value={light.intensity as number}
+        default={latest.light.intensity.default}
+        onChange={(value) => changeLightProperty("intensity", value)}
+      />
 
-        <FieldArray
-          label={t("Light position")}
-          fieldSpec={latest.light.position}
-          type="number"
-          length={latest.light.position.length}
-          value={light.position as number[]}
-          default={latest.light.position.default}
-          onChange={(value) => this.changeLightProperty("position", value)}
-        />
+      <FieldArray
+        label={t("Light position")}
+        fieldSpec={latest.light.position}
+        type="number"
+        length={latest.light.position.length}
+        value={light.position as number[]}
+        default={latest.light.position.default}
+        onChange={(value) => changeLightProperty("position", value)}
+      />
 
-        <FieldString
-          label={t("Terrain source")}
-          fieldSpec={latest.terrain.source}
-          data-wd-key="modal:settings.maputnik:terrain_source"
-          value={terrain.source}
-          onChange={(value) => this.changeTerrainProperty("source", value)}
-        />
+      <FieldString
+        label={t("Terrain source")}
+        fieldSpec={latest.terrain.source}
+        data-wd-key="modal:settings.maputnik:terrain_source"
+        value={terrain.source}
+        onChange={(value) => changeTerrainProperty("source", value)}
+      />
 
-        <FieldNumber
-          label={t("Terrain exaggeration")}
-          data-wd-key="modal:settings.terrain-exaggeration"
-          fieldSpec={latest.terrain.exaggeration}
-          value={terrain.exaggeration}
-          default={latest.terrain.exaggeration.default}
-          onChange={(value) => this.changeTerrainProperty("exaggeration", value)}
-        />
+      <FieldNumber
+        label={t("Terrain exaggeration")}
+        data-wd-key="modal:settings.terrain-exaggeration"
+        fieldSpec={latest.terrain.exaggeration}
+        value={terrain.exaggeration}
+        default={latest.terrain.exaggeration.default}
+        onChange={(value) => changeTerrainProperty("exaggeration", value)}
+      />
 
-        <FieldNumber
-          label={t("Transition delay")}
-          data-wd-key="modal:settings.transition-delay"
-          fieldSpec={latest.transition.delay}
-          value={transition.delay}
-          default={latest.transition.delay.default}
-          onChange={(value) => this.changeTransitionProperty("delay", value)}
-        />
+      <FieldNumber
+        label={t("Transition delay")}
+        data-wd-key="modal:settings.transition-delay"
+        fieldSpec={latest.transition.delay}
+        value={transition.delay}
+        default={latest.transition.delay.default}
+        onChange={(value) => changeTransitionProperty("delay", value)}
+      />
 
-        <FieldNumber
-          label={t("Transition duration")}
-          data-wd-key="modal:settings.transition-duration"
-          fieldSpec={latest.transition.duration}
-          value={transition.duration}
-          default={latest.transition.duration.default}
-          onChange={(value) => this.changeTransitionProperty("duration", value)}
-        />
+      <FieldNumber
+        label={t("Transition duration")}
+        data-wd-key="modal:settings.transition-duration"
+        fieldSpec={latest.transition.duration}
+        value={transition.duration}
+        default={latest.transition.duration.default}
+        onChange={(value) => changeTransitionProperty("duration", value)}
+      />
 
-        <FieldSelect
-          label={t("Projection")}
-          data-wd-key="modal:settings.projection"
-          options={[
-            ["", "Undefined"],
-            ["mercator", "Mercator"],
-            ["globe", "Globe"],
-            ["vertical-perspective", "Vertical Perspective"]
-          ]}
-          value={projection?.type?.toString() || ""}
-          onChange={(value) => this.changeProjectionType(value)}
-        />
+      <FieldSelect
+        label={t("Projection")}
+        data-wd-key="modal:settings.projection"
+        options={[
+          ["", "Undefined"],
+          ["mercator", "Mercator"],
+          ["globe", "Globe"],
+          ["vertical-perspective", "Vertical Perspective"]
+        ]}
+        value={projection?.type?.toString() || ""}
+        onChange={(value) => changeProjectionType(value)}
+      />
 
-        <FieldSelect
-          label={fsa.maputnik.style_renderer.label}
-          fieldSpec={fsa.maputnik.style_renderer}
-          data-wd-key="modal:settings.maputnik:renderer"
-          options={[
-            ["mlgljs", "MapLibreGL JS"],
-            ["ol", t("Open Layers (experimental)")],
-          ]}
-          value={metadata["maputnik:renderer"] || "mlgljs"}
-          onChange={(value) => onChangeMetadataProperty("maputnik:renderer", value)}
-        />
-      </div>
-    </Modal>;
-  }
-}
+      <FieldSelect
+        label={fsa.maputnik.style_renderer.label}
+        fieldSpec={fsa.maputnik.style_renderer}
+        data-wd-key="modal:settings.maputnik:renderer"
+        options={[
+          ["mlgljs", "MapLibreGL JS"],
+          ["ol", t("Open Layers (experimental)")],
+        ]}
+        value={metadata["maputnik:renderer"] || "mlgljs"}
+        onChange={(value) => onChangeMetadataProperty("maputnik:renderer", value)}
+      />
+    </div>
+  </Modal>;
+};
 
 export const ModalSettings = withTranslation()(ModalSettingsInternal);

src/components/modals/ModalShortcuts.tsx

@@ -10,128 +10,126 @@ type ModalShortcutsInternalProps = {
 } & WithTranslation;
 
 
-class ModalShortcutsInternal extends React.Component<ModalShortcutsInternalProps> {
-  render() {
-    const t = this.props.t;
-    const help = [
-      {
-        key: <kbd>?</kbd>,
-        text: t("Shortcuts menu")
-      },
-      {
-        key: <kbd>o</kbd>,
-        text: t("Open modal")
-      },
-      {
-        key: <kbd>e</kbd>,
-        text: t("Export modal")
-      },
-      {
-        key: <kbd>d</kbd>,
-        text: t("Data Sources modal")
-      },
-      {
-        key: <kbd>s</kbd>,
-        text: t("Style Settings modal")
-      },
-      {
-        key: <kbd>i</kbd>,
-        text: t("Toggle inspect")
-      },
-      {
-        key: <kbd>m</kbd>,
-        text: t("Focus map")
-      },
-      {
-        key: <kbd>!</kbd>,
-        text: t("Debug modal")
-      },
-    ];
+const ModalShortcutsInternal: React.FC<ModalShortcutsInternalProps> = (props) => {
+  const t = props.t;
+  const help = [
+    {
+      key: <kbd>?</kbd>,
+      text: t("Shortcuts menu")
+    },
+    {
+      key: <kbd>o</kbd>,
+      text: t("Open modal")
+    },
+    {
+      key: <kbd>e</kbd>,
+      text: t("Export modal")
+    },
+    {
+      key: <kbd>d</kbd>,
+      text: t("Data Sources modal")
+    },
+    {
+      key: <kbd>s</kbd>,
+      text: t("Style Settings modal")
+    },
+    {
+      key: <kbd>i</kbd>,
+      text: t("Toggle inspect")
+    },
+    {
+      key: <kbd>m</kbd>,
+      text: t("Focus map")
+    },
+    {
+      key: <kbd>!</kbd>,
+      text: t("Debug modal")
+    },
+  ];
 
 
-    const mapShortcuts = [
-      {
-        key: <kbd>+</kbd>,
-        text: t("Increase the zoom level by 1.",)
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>+</kbd></>,
-        text: t("Increase the zoom level by 2.",)
-      },
-      {
-        key: <kbd>-</kbd>,
-        text: t("Decrease the zoom level by 1.",)
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>-</kbd></>,
-        text: t("Decrease the zoom level by 2.",)
-      },
-      {
-        key: <kbd>Up</kbd>,
-        text: t("Pan up by 100 pixels.",)
-      },
-      {
-        key: <kbd>Down</kbd>,
-        text: t("Pan down by 100 pixels.",)
-      },
-      {
-        key: <kbd>Left</kbd>,
-        text: t("Pan left by 100 pixels.",)
-      },
-      {
-        key: <kbd>Right</kbd>,
-        text: t("Pan right by 100 pixels.",)
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>Right</kbd></>,
-        text: t("Increase the rotation by 15 degrees.",)
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>Left</kbd></>,
-        text: t("Decrease the rotation by 15 degrees.")
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>Up</kbd></>,
-        text: t("Increase the pitch by 10 degrees.")
-      },
-      {
-        key: <><kbd>Shift</kbd> + <kbd>Down</kbd></>,
-        text: t("Decrease the pitch by 10 degrees.")
-      },
-    ];
+  const mapShortcuts = [
+    {
+      key: <kbd>+</kbd>,
+      text: t("Increase the zoom level by 1.",)
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>+</kbd></>,
+      text: t("Increase the zoom level by 2.",)
+    },
+    {
+      key: <kbd>-</kbd>,
+      text: t("Decrease the zoom level by 1.",)
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>-</kbd></>,
+      text: t("Decrease the zoom level by 2.",)
+    },
+    {
+      key: <kbd>Up</kbd>,
+      text: t("Pan up by 100 pixels.",)
+    },
+    {
+      key: <kbd>Down</kbd>,
+      text: t("Pan down by 100 pixels.",)
+    },
+    {
+      key: <kbd>Left</kbd>,
+      text: t("Pan left by 100 pixels.",)
+    },
+    {
+      key: <kbd>Right</kbd>,
+      text: t("Pan right by 100 pixels.",)
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>Right</kbd></>,
+      text: t("Increase the rotation by 15 degrees.",)
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>Left</kbd></>,
+      text: t("Decrease the rotation by 15 degrees.")
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>Up</kbd></>,
+      text: t("Increase the pitch by 10 degrees.")
+    },
+    {
+      key: <><kbd>Shift</kbd> + <kbd>Down</kbd></>,
+      text: t("Decrease the pitch by 10 degrees.")
+    },
+  ];
 
 
-    return <Modal
-      data-wd-key="modal:shortcuts"
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Shortcuts")}
-    >
-      <section className="maputnik-modal-section maputnik-modal-shortcuts">
-        <p>
-          <Trans t={t}>
-            Press <code>ESC</code> to lose focus of any active elements, then press one of:
-          </Trans>
-        </p>
-        <dl>
-          {help.map((item, idx) => {
-            return <div key={idx} className="maputnik-modal-shortcuts__shortcut">
-              <dt key={"dt"+idx}>{item.key}</dt>
-              <dd key={"dd"+idx}>{item.text}</dd>
-            </div>;
-          })}
-        </dl>
-        <p>{t("If the Map is in focused you can use the following shortcuts")}</p>
-        <ul>
-          {mapShortcuts.map((item, idx) => {
-            return <li key={idx}>
-              <span>{item.key}</span> {item.text}
-            </li>;
-          })}
-        </ul>
-      </section>
-    </Modal>;
-  }
-}
+  return <Modal
+    data-wd-key="modal:shortcuts"
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Shortcuts")}
+  >
+    <section className="maputnik-modal-section maputnik-modal-shortcuts">
+      <p>
+        <Trans t={t}>
+          Press <code>ESC</code> to lose focus of any active elements, then press one of:
+        </Trans>
+      </p>
+      <dl>
+        {help.map((item, idx) => {
+          return <div key={idx} className="maputnik-modal-shortcuts__shortcut">
+            <dt key={"dt"+idx}>{item.key}</dt>
+            <dd key={"dd"+idx}>{item.text}</dd>
+          </div>;
+        })}
+      </dl>
+      <p>{t("If the Map is in focused you can use the following shortcuts")}</p>
+      <ul>
+        {mapShortcuts.map((item, idx) => {
+          return <li key={idx}>
+            <span>{item.key}</span> {item.text}
+          </li>;
+        })}
+      </ul>
+    </section>
+  </Modal>;
+};
 
 export const ModalShortcuts = withTranslation()(ModalShortcutsInternal);

src/components/modals/ModalSources.tsx

@@ -1,4 +1,4 @@
-import React from "react";
+import React, { useState } from "react";
 import {MdAddCircleOutline, MdDelete} from "react-icons/md";
 import latest from "@maplibre/maplibre-gl-style-spec/dist/latest.json";
 import type {GeoJSONSourceSpecification, RasterDEMSourceSpecification, RasterSourceSpecification, SourceSpecification, VectorSourceSpecification} from "maplibre-gl";
@@ -23,23 +23,21 @@ type PublicSourceProps = {
   onSelect(...args: unknown[]): unknown
 };
 
-class PublicSource extends React.Component<PublicSourceProps> {
-  render() {
-    return <div className="maputnik-public-source">
-      <InputButton
-        className="maputnik-public-source-select"
-        onClick={() => this.props.onSelect(this.props.id)}
-      >
-        <div className="maputnik-public-source-info">
-          <p className="maputnik-public-source-name">{this.props.title}</p>
-          <p className="maputnik-public-source-id">#{this.props.id}</p>
-        </div>
-        <span className="maputnik-space" />
-        <MdAddCircleOutline />
-      </InputButton>
-    </div>;
-  }
-}
+const PublicSource: React.FC<PublicSourceProps> = (props) => {
+  return <div className="maputnik-public-source">
+    <InputButton
+      className="maputnik-public-source-select"
+      onClick={() => props.onSelect(props.id)}
+    >
+      <div className="maputnik-public-source-info">
+        <p className="maputnik-public-source-name">{props.title}</p>
+        <p className="maputnik-public-source-id">#{props.id}</p>
+      </div>
+      <span className="maputnik-space" />
+      <MdAddCircleOutline />
+    </InputButton>
+  </div>;
+};
 
 function editorMode(source: SourceSpecification) {
   if(source.type === "raster") {
@@ -79,197 +77,184 @@ type ActiveModalSourcesTypeEditorProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class ActiveModalSourcesTypeEditor extends React.Component<ActiveModalSourcesTypeEditorProps> {
-  render() {
-    const t = this.props.t;
-    return <div className="maputnik-active-source-type-editor">
-      <div className="maputnik-active-source-type-editor-header">
-        <span className="maputnik-active-source-type-editor-header-id">#{this.props.sourceId}</span>
-        <span className="maputnik-space" />
-        <InputButton
-          aria-label={t("Remove '{{sourceId}}' source", {sourceId: this.props.sourceId})}
-          className="maputnik-active-source-type-editor-header-delete"
-          onClick={()=> this.props.onDelete(this.props.sourceId)}
-          style={{backgroundColor: "transparent"}}
-        >
-          <MdDelete />
-        </InputButton>
-      </div>
-      <div className="maputnik-active-source-type-editor-content">
-        <ModalSourcesTypeEditor
-          onChange={this.props.onChange}
-          mode={editorMode(this.props.source)}
-          source={this.props.source}
-        />
-      </div>
-    </div>;
-  }
-}
+const ActiveModalSourcesTypeEditor: React.FC<ActiveModalSourcesTypeEditorProps> = (props) => {
+  const t = props.t;
+  return <div className="maputnik-active-source-type-editor">
+    <div className="maputnik-active-source-type-editor-header">
+      <span className="maputnik-active-source-type-editor-header-id">#{props.sourceId}</span>
+      <span className="maputnik-space" />
+      <InputButton
+        aria-label={t("Remove '{{sourceId}}' source", {sourceId: props.sourceId})}
+        className="maputnik-active-source-type-editor-header-delete"
+        onClick={()=> props.onDelete(props.sourceId)}
+        style={{backgroundColor: "transparent"}}
+      >
+        <MdDelete />
+      </InputButton>
+    </div>
+    <div className="maputnik-active-source-type-editor-content">
+      <ModalSourcesTypeEditor
+        onChange={props.onChange}
+        mode={editorMode(props.source)}
+        source={props.source}
+      />
+    </div>
+  </div>;
+};
 
 type AddSourceProps = {
   onAdd(...args: unknown[]): unknown
 } & WithTranslation;
 
-type AddSourceState = {
-  mode: EditorMode
-  sourceId: string
-  source: SourceSpecification
-};
+function defaultSource(mode: EditorMode, currentSource: SourceSpecification | undefined): SourceSpecification {
+  const source = currentSource || {};
+  const {protocol} = window.location;
 
-class AddSource extends React.Component<AddSourceProps, AddSourceState> {
-  constructor(props: AddSourceProps) {
-    super(props);
-    this.state = {
-      mode: "tilejson_vector",
-      sourceId: generateId(),
-      source: this.defaultSource("tilejson_vector"),
+  switch(mode) {
+    case "pmtiles_vector": return {
+      type: "vector",
+      url: `${protocol}//localhost:3000/file.pmtiles`
     };
-  }
-
-  defaultSource(mode: EditorMode): SourceSpecification {
-    const source = (this.state || {}).source || {};
-    const {protocol} = window.location;
-
-    switch(mode) {
-      case "pmtiles_vector": return {
-        type: "vector",
-        url: `${protocol}//localhost:3000/file.pmtiles`
-      };
-      case "geojson_url": return {
-        type: "geojson",
-        data: `${protocol}//localhost:3000/geojson.json`
-      };
-      case "geojson_json": return {
-        type: "geojson",
-        cluster: (source as GeoJSONSourceSpecification).cluster || false,
-        data: ""
-      };
-      case "tilejson_vector": return {
-        type: "vector",
-        url: (source as VectorSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
-      };
-      case "tile_vector": return {
-        type: "vector",
-        tiles: (source as VectorSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.pbf`],
-        minzoom: (source as VectorSourceSpecification).minzoom || 0,
-        maxzoom: (source as VectorSourceSpecification).maxzoom || 14,
-        scheme: (source as VectorSourceSpecification).scheme || "xyz"
-      };
-      case "tilejson_raster": return {
-        type: "raster",
-        url: (source as RasterSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
-      };
-      case "tile_raster": return {
-        type: "raster",
-        tiles: (source as RasterSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
-        minzoom: (source as RasterSourceSpecification).minzoom || 0,
-        maxzoom: (source as RasterSourceSpecification).maxzoom || 14,
-        scheme: (source as RasterSourceSpecification).scheme || "xyz",
-        tileSize: (source as RasterSourceSpecification).tileSize || 512,
-      };
-      case "tilejson_raster-dem": return {
-        type: "raster-dem",
-        url: (source as RasterDEMSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
-      };
-      case "tilexyz_raster-dem": return {
-        type: "raster-dem",
-        tiles: (source as RasterDEMSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
-        minzoom: (source as RasterDEMSourceSpecification).minzoom || 0,
-        maxzoom: (source as RasterDEMSourceSpecification).maxzoom || 14,
-        tileSize: (source as RasterDEMSourceSpecification).tileSize || 512
-      };
-      case "image": return {
-        type: "image",
-        url: `${protocol}//localhost:3000/image.png`,
-        coordinates: [
-          [0,0],
-          [0,0],
-          [0,0],
-          [0,0],
-        ],
-      };
-      case "video": return {
-        type: "video",
-        urls: [
-          `${protocol}//localhost:3000/movie.mp4`
-        ],
-        coordinates: [
-          [0,0],
-          [0,0],
-          [0,0],
-          [0,0],
-        ],
-      };
-      default: return {} as any;
-    }
-  }
-
-  onAdd = () => {
-    const {source, sourceId} = this.state;
-    this.props.onAdd(sourceId, source);
-  };
-
-  onChangeSource = (source: SourceSpecification) => {
-    this.setState({source});
-  };
-
-  render() {
-    const t = this.props.t;
-    // Kind of a hack because the type changes, however maputnik has 1..n
-    // options per type, for example
-    //
-    //  - 'geojson' - 'GeoJSON (URL)' and 'GeoJSON (JSON)'
-    //  - 'raster' - 'Raster (TileJSON URL)' and 'Raster (XYZ URL)'
-    //
-    // So we just ignore the values entirely as they are self explanatory
-    const sourceTypeFieldSpec = {
-      doc: latest.source_vector.type.doc
+    case "geojson_url": return {
+      type: "geojson",
+      data: `${protocol}//localhost:3000/geojson.json`
     };
-
-    return <div className="maputnik-add-source">
-      <FieldString
-        label={t("Source ID")}
-        fieldSpec={{doc: t("Unique ID that identifies the source and is used in the layer to reference the source.")}}
-        value={this.state.sourceId}
-        onChange={(v: string) => this.setState({ sourceId: v})}
-        data-wd-key="modal:sources.add.source_id"
-      />
-      <FieldSelect
-        label={t("Source Type")}
-        fieldSpec={sourceTypeFieldSpec}
-        options={[
-          ["geojson_json", t("GeoJSON (JSON)")],
-          ["geojson_url", t("GeoJSON (URL)")],
-          ["tilejson_vector", t("Vector (TileJSON URL)")],
-          ["tile_vector", t("Vector (Tile URLs)")],
-          ["tilejson_raster", t("Raster (TileJSON URL)")],
-          ["tile_raster", t("Raster (Tile URLs)")],
-          ["tilejson_raster-dem", t("Raster DEM (TileJSON URL)")],
-          ["tilexyz_raster-dem", t("Raster DEM (XYZ URLs)")],
-          ["pmtiles_vector", t("Vector (PMTiles)")],
-          ["image", t("Image")],
-          ["video", t("Video")],
-        ]}
-        onChange={mode => this.setState({mode: mode as EditorMode, source: this.defaultSource(mode as EditorMode)})}
-        value={this.state.mode as string}
-        data-wd-key="modal:sources.add.source_type"
-      />
-      <ModalSourcesTypeEditor
-        onChange={this.onChangeSource}
-        mode={this.state.mode}
-        source={this.state.source}
-      />
-      <InputButton
-        className="maputnik-add-source-button"
-        onClick={this.onAdd}
-        data-wd-key="modal:sources.add.add_source"
-      >
-        {t("Add Source")}
-      </InputButton>
-    </div>;
+    case "geojson_json": return {
+      type: "geojson",
+      cluster: (source as GeoJSONSourceSpecification).cluster || false,
+      data: ""
+    };
+    case "tilejson_vector": return {
+      type: "vector",
+      url: (source as VectorSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
+    };
+    case "tile_vector": return {
+      type: "vector",
+      tiles: (source as VectorSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.pbf`],
+      minzoom: (source as VectorSourceSpecification).minzoom || 0,
+      maxzoom: (source as VectorSourceSpecification).maxzoom || 14,
+      scheme: (source as VectorSourceSpecification).scheme || "xyz"
+    };
+    case "tilejson_raster": return {
+      type: "raster",
+      url: (source as RasterSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
+    };
+    case "tile_raster": return {
+      type: "raster",
+      tiles: (source as RasterSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
+      minzoom: (source as RasterSourceSpecification).minzoom || 0,
+      maxzoom: (source as RasterSourceSpecification).maxzoom || 14,
+      scheme: (source as RasterSourceSpecification).scheme || "xyz",
+      tileSize: (source as RasterSourceSpecification).tileSize || 512,
+    };
+    case "tilejson_raster-dem": return {
+      type: "raster-dem",
+      url: (source as RasterDEMSourceSpecification).url || `${protocol}//localhost:3000/tilejson.json`
+    };
+    case "tilexyz_raster-dem": return {
+      type: "raster-dem",
+      tiles: (source as RasterDEMSourceSpecification).tiles || [`${protocol}//localhost:3000/{x}/{y}/{z}.png`],
+      minzoom: (source as RasterDEMSourceSpecification).minzoom || 0,
+      maxzoom: (source as RasterDEMSourceSpecification).maxzoom || 14,
+      tileSize: (source as RasterDEMSourceSpecification).tileSize || 512
+    };
+    case "image": return {
+      type: "image",
+      url: `${protocol}//localhost:3000/image.png`,
+      coordinates: [
+        [0,0],
+        [0,0],
+        [0,0],
+        [0,0],
+      ],
+    };
+    case "video": return {
+      type: "video",
+      urls: [
+        `${protocol}//localhost:3000/movie.mp4`
+      ],
+      coordinates: [
+        [0,0],
+        [0,0],
+        [0,0],
+        [0,0],
+      ],
+    };
+    default: return {} as any;
   }
 }
 
+const AddSource: React.FC<AddSourceProps> = (props) => {
+  const [mode, setMode] = useState<EditorMode>("tilejson_vector");
+  const [sourceId, setSourceId] = useState<string>(() => generateId());
+  const [source, setSource] = useState<SourceSpecification>(() => defaultSource("tilejson_vector", undefined));
+
+  const onAdd = () => {
+    props.onAdd(sourceId, source);
+  };
+
+  const onChangeSource = (newSource: SourceSpecification) => {
+    setSource(newSource);
+  };
+
+  const t = props.t;
+  // Kind of a hack because the type changes, however maputnik has 1..n
+  // options per type, for example
+  //
+  //  - 'geojson' - 'GeoJSON (URL)' and 'GeoJSON (JSON)'
+  //  - 'raster' - 'Raster (TileJSON URL)' and 'Raster (XYZ URL)'
+  //
+  // So we just ignore the values entirely as they are self explanatory
+  const sourceTypeFieldSpec = {
+    doc: latest.source_vector.type.doc
+  };
+
+  return <div className="maputnik-add-source">
+    <FieldString
+      label={t("Source ID")}
+      fieldSpec={{doc: t("Unique ID that identifies the source and is used in the layer to reference the source.")}}
+      value={sourceId}
+      onChange={(v: string) => setSourceId(v)}
+      data-wd-key="modal:sources.add.source_id"
+    />
+    <FieldSelect
+      label={t("Source Type")}
+      fieldSpec={sourceTypeFieldSpec}
+      options={[
+        ["geojson_json", t("GeoJSON (JSON)")],
+        ["geojson_url", t("GeoJSON (URL)")],
+        ["tilejson_vector", t("Vector (TileJSON URL)")],
+        ["tile_vector", t("Vector (Tile URLs)")],
+        ["tilejson_raster", t("Raster (TileJSON URL)")],
+        ["tile_raster", t("Raster (Tile URLs)")],
+        ["tilejson_raster-dem", t("Raster DEM (TileJSON URL)")],
+        ["tilexyz_raster-dem", t("Raster DEM (XYZ URLs)")],
+        ["pmtiles_vector", t("Vector (PMTiles)")],
+        ["image", t("Image")],
+        ["video", t("Video")],
+      ]}
+      onChange={newMode => {
+        setMode(newMode as EditorMode);
+        setSource(defaultSource(newMode as EditorMode, source));
+      }}
+      value={mode as string}
+      data-wd-key="modal:sources.add.source_type"
+    />
+    <ModalSourcesTypeEditor
+      onChange={onChangeSource}
+      mode={mode}
+      source={source}
+    />
+    <InputButton
+      className="maputnik-add-source-button"
+      onClick={onAdd}
+      data-wd-key="modal:sources.add.add_source"
+    >
+      {t("Add Source")}
+    </InputButton>
+  </div>;
+};
+
 type ModalSourcesInternalProps = {
   mapStyle: StyleSpecificationWithId
   isOpen: boolean
@@ -277,70 +262,68 @@ type ModalSourcesInternalProps = {
   onStyleChanged: OnStyleChangedCallback
 } & WithTranslation;
 
-class ModalSourcesInternal extends React.Component<ModalSourcesInternalProps> {
-  stripTitle(source: SourceSpecification & {title?: string}): SourceSpecification {
-    const strippedSource = {...source};
-    delete strippedSource["title"];
-    return strippedSource;
-  }
-
-  render() {
-    const {t, mapStyle} = this.props;
-    const i18nProps = {t, i18n: this.props.i18n, tReady: this.props.tReady};
-    const activeSources = Object.keys(mapStyle.sources).map(sourceId => {
-      const source = mapStyle.sources[sourceId];
-      return <ActiveModalSourcesTypeEditor
-        key={sourceId}
-        sourceId={sourceId}
-        source={source}
-        onChange={(src: SourceSpecification) => this.props.onStyleChanged(changeSource(mapStyle, sourceId, src))}
-        onDelete={() => this.props.onStyleChanged(deleteSource(mapStyle, sourceId))}
-        {...i18nProps}
-      />;
-    });
-
-    const tilesetOptions = Object.keys(publicSources).filter((sourceId: string) => !(sourceId in mapStyle.sources)).map((sourceId: string) => {
-      const source = publicSources[sourceId as keyof typeof publicSources] as SourceSpecification & {title: string};
-      return <PublicSource
-        key={sourceId}
-        id={sourceId}
-        type={source.type}
-        title={source.title}
-        onSelect={() => this.props.onStyleChanged(addSource(mapStyle, sourceId, this.stripTitle(source)))}
-      />;
-    });
-
-    return <Modal
-      data-wd-key="modal:sources"
-      isOpen={this.props.isOpen}
-      onOpenToggle={this.props.onOpenToggle}
-      title={t("Sources")}
-    >
-      <section className="maputnik-modal-section">
-        <h1>{t("Active Sources")}</h1>
-        {activeSources}
-      </section>
-
-      <section className="maputnik-modal-section">
-        <h1>{t("Choose Public Source")}</h1>
-        <p>
-          {t("Add one of the publicly available sources to your style.")}
-        </p>
-        <div className="maputnik-public-sources" style={{maxWidth: 500}}>
-          {tilesetOptions}
-        </div>
-      </section>
-
-      <section className="maputnik-modal-section">
-        <h1>{t("Add New Source")}</h1>
-        <p>{t("Add a new source to your style. You can only choose the source type and id at creation time!")}</p>
-        <AddSource
-          onAdd={(sourceId: string, source: SourceSpecification) => this.props.onStyleChanged(addSource(mapStyle, sourceId, source))}
-          {...i18nProps}
-        />
-      </section>
-    </Modal>;
-  }
+function stripTitle(source: SourceSpecification & {title?: string}): SourceSpecification {
+  const strippedSource = {...source};
+  delete strippedSource["title"];
+  return strippedSource;
 }
 
+const ModalSourcesInternal: React.FC<ModalSourcesInternalProps> = (props) => {
+  const {t, mapStyle} = props;
+  const i18nProps = {t, i18n: props.i18n, tReady: props.tReady};
+  const activeSources = Object.keys(mapStyle.sources).map(sourceId => {
+    const source = mapStyle.sources[sourceId];
+    return <ActiveModalSourcesTypeEditor
+      key={sourceId}
+      sourceId={sourceId}
+      source={source}
+      onChange={(src: SourceSpecification) => props.onStyleChanged(changeSource(mapStyle, sourceId, src))}
+      onDelete={() => props.onStyleChanged(deleteSource(mapStyle, sourceId))}
+      {...i18nProps}
+    />;
+  });
+
+  const tilesetOptions = Object.keys(publicSources).filter((sourceId: string) => !(sourceId in mapStyle.sources)).map((sourceId: string) => {
+    const source = publicSources[sourceId as keyof typeof publicSources] as SourceSpecification & {title: string};
+    return <PublicSource
+      key={sourceId}
+      id={sourceId}
+      type={source.type}
+      title={source.title}
+      onSelect={() => props.onStyleChanged(addSource(mapStyle, sourceId, stripTitle(source)))}
+    />;
+  });
+
+  return <Modal
+    data-wd-key="modal:sources"
+    isOpen={props.isOpen}
+    onOpenToggle={props.onOpenToggle}
+    title={t("Sources")}
+  >
+    <section className="maputnik-modal-section">
+      <h1>{t("Active Sources")}</h1>
+      {activeSources}
+    </section>
+
+    <section className="maputnik-modal-section">
+      <h1>{t("Choose Public Source")}</h1>
+      <p>
+        {t("Add one of the publicly available sources to your style.")}
+      </p>
+      <div className="maputnik-public-sources" style={{maxWidth: 500}}>
+        {tilesetOptions}
+      </div>
+    </section>
+
+    <section className="maputnik-modal-section">
+      <h1>{t("Add New Source")}</h1>
+      <p>{t("Add a new source to your style. You can only choose the source type and id at creation time!")}</p>
+      <AddSource
+        onAdd={(sourceId: string, source: SourceSpecification) => props.onStyleChanged(addSource(mapStyle, sourceId, source))}
+        {...i18nProps}
+      />
+    </section>
+  </Modal>;
+};
+
 export const ModalSources = withTranslation()(ModalSourcesInternal);

src/components/modals/ModalSourcesTypeEditor.tsx

@@ -24,23 +24,21 @@ type TileJSONSourceEditorProps = {
 } & WithTranslation;
 
 
-class TileJSONSourceEditor extends React.Component<TileJSONSourceEditorProps> {
-  render() {
-    const t = this.props.t;
-    return <div>
-      <FieldUrl
-        label={t("TileJSON URL")}
-        fieldSpec={latest.source_vector.url}
-        value={this.props.source.url}
-        onChange={url => this.props.onChange({
-          ...this.props.source,
-          url: url
-        })}
-      />
-      {this.props.children}
-    </div>;
-  }
-}
+const TileJSONSourceEditor: React.FC<TileJSONSourceEditorProps> = (props) => {
+  const t = props.t;
+  return <div>
+    <FieldUrl
+      label={t("TileJSON URL")}
+      fieldSpec={latest.source_vector.url}
+      value={props.source.url}
+      onChange={url => props.onChange({
+        ...props.source,
+        url: url
+      })}
+    />
+    {props.children}
+  </div>;
+};
 
 type TileURLSourceEditorProps = {
   source: {
@@ -53,66 +51,63 @@ type TileURLSourceEditorProps = {
   children?: React.ReactNode
 } & WithTranslation;
 
-class TileURLSourceEditor extends React.Component<TileURLSourceEditorProps> {
-  changeTileUrls(tiles: string[]) {
-    this.props.onChange({
-      ...this.props.source,
+const TileURLSourceEditor: React.FC<TileURLSourceEditorProps> = (props) => {
+  function changeTileUrls(tiles: string[]) {
+    props.onChange({
+      ...props.source,
       tiles,
     });
   }
 
-  renderTileUrls() {
-    const tiles = this.props.source.tiles || [];
+  function renderTileUrls() {
+    const tiles = props.source.tiles || [];
     return <FieldDynamicArray
-      label={this.props.t("Tile URL")}
+      label={props.t("Tile URL")}
       fieldSpec={latest.source_vector.tiles}
       type="url"
       value={tiles}
-      onChange={this.changeTileUrls.bind(this)}
+      onChange={changeTileUrls}
     />;
   }
 
-  render() {
-    const t = this.props.t;
-    return <div>
-      {this.renderTileUrls()}
-      <FieldSelect
-        label={t("Scheme Type")}
-        fieldSpec={latest.source_vector.scheme}
-        options={[
-          ["xyz", "xyz (Slippy map tilenames scheme)"],
-          ["tms", "tms (OSGeo spec scheme)"],
-        ]}
-        onChange={scheme => this.props.onChange({
-          ...this.props.source,
-          scheme
-        })}
-        value={this.props.source.scheme}
-        data-wd-key="modal:sources.add.scheme_type"
-      />
-      <FieldNumber
-        label={t("Min Zoom")}
-        fieldSpec={latest.source_vector.minzoom}
-        value={this.props.source.minzoom || 0}
-        onChange={minzoom => this.props.onChange({
-          ...this.props.source,
-          minzoom: minzoom
-        })}
-      />
-      <FieldNumber
-        label={t("Max Zoom")}
-        fieldSpec={latest.source_vector.maxzoom}
-        value={this.props.source.maxzoom || 22}
-        onChange={maxzoom => this.props.onChange({
-          ...this.props.source,
-          maxzoom: maxzoom
-        })}
-      />
-      {this.props.children}
-    </div>;
-
-  }
-}
+  const t = props.t;
+  return <div>
+    {renderTileUrls()}
+    <FieldSelect
+      label={t("Scheme Type")}
+      fieldSpec={latest.source_vector.scheme}
+      options={[
+        ["xyz", "xyz (Slippy map tilenames scheme)"],
+        ["tms", "tms (OSGeo spec scheme)"],
+      ]}
+      onChange={scheme => props.onChange({
+        ...props.source,
+        scheme
+      })}
+      value={props.source.scheme}
+      data-wd-key="modal:sources.add.scheme_type"
+    />
+    <FieldNumber
+      label={t("Min Zoom")}
+      fieldSpec={latest.source_vector.minzoom}
+      value={props.source.minzoom || 0}
+      onChange={minzoom => props.onChange({
+        ...props.source,
+        minzoom: minzoom
+      })}
+    />
+    <FieldNumber
+      label={t("Max Zoom")}
+      fieldSpec={latest.source_vector.maxzoom}
+      value={props.source.maxzoom || 22}
+      onChange={maxzoom => props.onChange({
+        ...props.source,
+        maxzoom: maxzoom
+      })}
+    />
+    {props.children}
+  </div>;
+};
 
 const createCornerLabels: (t: TFunction) => { label: string, key: string }[] = (t) => ([
   { label: t("Coord top left"), key: "top left" },
@@ -129,45 +124,43 @@ type ImageSourceEditorProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class ImageSourceEditor extends React.Component<ImageSourceEditorProps> {
-  render() {
-    const t = this.props.t;
-    const changeCoord = (idx: number, val: [number, number]) => {
-      const coordinates = this.props.source.coordinates.slice(0);
-      coordinates[idx] = val;
+const ImageSourceEditor: React.FC<ImageSourceEditorProps> = (props) => {
+  const t = props.t;
+  const changeCoord = (idx: number, val: [number, number]) => {
+    const coordinates = props.source.coordinates.slice(0);
+    coordinates[idx] = val;
 
-      this.props.onChange({
-        ...this.props.source,
-        coordinates,
-      });
-    };
+    props.onChange({
+      ...props.source,
+      coordinates,
+    });
+  };
 
-    return <div>
-      <FieldUrl
-        label={t("Image URL")}
-        fieldSpec={latest.source_image.url}
-        value={this.props.source.url}
-        onChange={url => this.props.onChange({
-          ...this.props.source,
-          url,
-        })}
-      />
-      {createCornerLabels(t).map(({label, key}, idx) => {
-        return (
-          <FieldArray
-            label={label}
-            key={key}
-            length={2}
-            type="number"
-            value={this.props.source.coordinates[idx]}
-            default={[0, 0]}
-            onChange={(val: [number, number]) => changeCoord(idx, val)}
-          />
-        );
+  return <div>
+    <FieldUrl
+      label={t("Image URL")}
+      fieldSpec={latest.source_image.url}
+      value={props.source.url}
+      onChange={url => props.onChange({
+        ...props.source,
+        url,
       })}
-    </div>;
-  }
-}
+    />
+    {createCornerLabels(t).map(({label, key}, idx) => {
+      return (
+        <FieldArray
+          label={label}
+          key={key}
+          length={2}
+          type="number"
+          value={props.source.coordinates[idx]}
+          default={[0, 0]}
+          onChange={(val: [number, number]) => changeCoord(idx, val)}
+        />
+      );
+    })}
+  </div>;
+};
 
 type VideoSourceEditorProps = {
   source: {
@@ -177,51 +170,49 @@ type VideoSourceEditorProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class VideoSourceEditor extends React.Component<VideoSourceEditorProps> {
-  render() {
-    const t = this.props.t;
-    const changeCoord = (idx: number, val: [number, number]) => {
-      const coordinates = this.props.source.coordinates.slice(0);
-      coordinates[idx] = val;
+const VideoSourceEditor: React.FC<VideoSourceEditorProps> = (props) => {
+  const t = props.t;
+  const changeCoord = (idx: number, val: [number, number]) => {
+    const coordinates = props.source.coordinates.slice(0);
+    coordinates[idx] = val;
 
-      this.props.onChange({
-        ...this.props.source,
-        coordinates,
-      });
-    };
+    props.onChange({
+      ...props.source,
+      coordinates,
+    });
+  };
 
-    const changeUrls = (urls: string[]) => {
-      this.props.onChange({
-        ...this.props.source,
-        urls,
-      });
-    };
+  const changeUrls = (urls: string[]) => {
+    props.onChange({
+      ...props.source,
+      urls,
+    });
+  };
 
-    return <div>
-      <FieldDynamicArray
-        label={t("Video URL")}
-        fieldSpec={latest.source_video.urls}
-        type="string"
-        value={this.props.source.urls}
-        default={[]}
-        onChange={changeUrls}
-      />
-      {createCornerLabels(t).map(({label, key}, idx) => {
-        return (
-          <FieldArray
-            label={label}
-            key={key}
-            length={2}
-            type="number"
-            value={this.props.source.coordinates[idx]}
-            default={[0, 0]}
-            onChange={(val: [number, number]) => changeCoord(idx, val)}
-          />
-        );
-      })}
-    </div>;
-  }
-}
+  return <div>
+    <FieldDynamicArray
+      label={t("Video URL")}
+      fieldSpec={latest.source_video.urls}
+      type="string"
+      value={props.source.urls}
+      default={[]}
+      onChange={changeUrls}
+    />
+    {createCornerLabels(t).map(({label, key}, idx) => {
+      return (
+        <FieldArray
+          label={label}
+          key={key}
+          length={2}
+          type="number"
+          value={props.source.coordinates[idx]}
+          default={[0, 0]}
+          onChange={(val: [number, number]) => changeCoord(idx, val)}
+        />
+      );
+    })}
+  </div>;
+};
 
 type GeoJSONSourceUrlEditorProps = {
   source: {
@@ -230,20 +221,18 @@ type GeoJSONSourceUrlEditorProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class GeoJSONSourceUrlEditor extends React.Component<GeoJSONSourceUrlEditorProps> {
-  render() {
-    const t = this.props.t;
-    return <FieldUrl
-      label={t("GeoJSON URL")}
-      fieldSpec={latest.source_geojson.data}
-      value={this.props.source.data}
-      onChange={data => this.props.onChange({
-        ...this.props.source,
-        data: data
-      })}
-    />;
-  }
-}
+const GeoJSONSourceUrlEditor: React.FC<GeoJSONSourceUrlEditorProps> = (props) => {
+  const t = props.t;
+  return <FieldUrl
+    label={t("GeoJSON URL")}
+    fieldSpec={latest.source_geojson.data}
+    value={props.source.data}
+    onChange={data => props.onChange({
+      ...props.source,
+      data: data
+    })}
+  />;
+};
 
 type GeoJSONSourceFieldJsonEditorProps = {
   source: {
@@ -253,35 +242,33 @@ type GeoJSONSourceFieldJsonEditorProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class GeoJSONSourceFieldJsonEditor extends React.Component<GeoJSONSourceFieldJsonEditorProps> {
-  render() {
-    const t = this.props.t;
-    return <div>
-      <Block label={t("GeoJSON")} fieldSpec={latest.source_geojson.data}>
-        <FieldJson
-          value={this.props.source.data}
-          lintType="json"
-          onChange={data => {
-            this.props.onChange({
-              ...this.props.source,
-              data,
-            });
-          }}
-        />
-      </Block>
-      <FieldCheckbox
-        label={t("Cluster")}
-        value={this.props.source.cluster}
-        onChange={cluster => {
-          this.props.onChange({
-            ...this.props.source,
-            cluster: cluster,
+const GeoJSONSourceFieldJsonEditor: React.FC<GeoJSONSourceFieldJsonEditorProps> = (props) => {
+  const t = props.t;
+  return <div>
+    <Block label={t("GeoJSON")} fieldSpec={latest.source_geojson.data}>
+      <FieldJson
+        value={props.source.data}
+        lintType="json"
+        onChange={data => {
+          props.onChange({
+            ...props.source,
+            data,
           });
         }}
       />
-    </div>;
-  }
-}
+    </Block>
+    <FieldCheckbox
+      label={t("Cluster")}
+      value={props.source.cluster}
+      onChange={cluster => {
+        props.onChange({
+          ...props.source,
+          cluster: cluster,
+        });
+      }}
+    />
+  </div>;
+};
 
 type PMTilesSourceEditorProps = {
   source: {
@@ -291,24 +278,22 @@ type PMTilesSourceEditorProps = {
   children?: React.ReactNode
 } & WithTranslation;
 
-class PMTilesSourceEditor extends React.Component<PMTilesSourceEditorProps> {
-  render() {
-    const t = this.props.t;
-    return <div>
-      <FieldUrl
-        label={t("PMTiles URL")}
-        fieldSpec={latest.source_vector.url}
-        value={this.props.source.url}
-        data-wd-key="modal:sources.add.source_url"
-        onChange={(url: string) => this.props.onChange({
-          ...this.props.source,
-          url: url.startsWith("pmtiles://") ? url : `pmtiles://${url}`
-        })}
-      />
-      {this.props.children}
-    </div>;
-  }
-}
+const PMTilesSourceEditor: React.FC<PMTilesSourceEditorProps> = (props) => {
+  const t = props.t;
+  return <div>
+    <FieldUrl
+      label={t("PMTiles URL")}
+      fieldSpec={latest.source_vector.url}
+      value={props.source.url}
+      data-wd-key="modal:sources.add.source_url"
+      onChange={(url: string) => props.onChange({
+        ...props.source,
+        url: url.startsWith("pmtiles://") ? url : `pmtiles://${url}`
+      })}
+    />
+    {props.children}
+  </div>;
+};
 
 type ModalSourcesTypeEditorInternalProps = {
   mode: EditorMode
@@ -316,63 +301,61 @@ type ModalSourcesTypeEditorInternalProps = {
   onChange(...args: unknown[]): unknown
 } & WithTranslation;
 
-class ModalSourcesTypeEditorInternal extends React.Component<ModalSourcesTypeEditorInternalProps> {
-  render() {
-    const t = this.props.t;
-    const commonProps = {
-      source: this.props.source,
-      onChange: this.props.onChange,
-      t: this.props.t,
-      i18n: this.props.i18n,
-      tReady: this.props.tReady,
-    };
-    switch(this.props.mode) {
-      case "geojson_url": return <GeoJSONSourceUrlEditor {...commonProps} />;
-      case "geojson_json": return <GeoJSONSourceFieldJsonEditor {...commonProps} />;
-      case "tilejson_vector": return <TileJSONSourceEditor {...commonProps} />;
-      case "tile_vector": return <TileURLSourceEditor {...commonProps} />;
-      case "tilejson_raster": return <TileJSONSourceEditor {...commonProps} />;
-      case "tile_raster": return <TileURLSourceEditor {...commonProps}>
-        <FieldNumber
-          label={t("Tile Size")}
-          fieldSpec={latest.source_raster.tileSize}
-          onChange={tileSize => this.props.onChange({
-            ...this.props.source,
-            tileSize: tileSize
-          })}
-          value={this.props.source.tileSize || latest.source_raster.tileSize.default}
-          data-wd-key="modal:sources.add.tile_size"
-        />
-      </TileURLSourceEditor>;
-      case "tilejson_raster-dem": return <TileJSONSourceEditor {...commonProps} />;
-      case "tilexyz_raster-dem": return <TileURLSourceEditor {...commonProps}>
-        <FieldNumber
-          label={t("Tile Size")}
-          fieldSpec={latest.source_raster_dem.tileSize}
-          onChange={tileSize => this.props.onChange({
-            ...this.props.source,
-            tileSize: tileSize
-          })}
-          value={this.props.source.tileSize || latest.source_raster_dem.tileSize.default}
-          data-wd-key="modal:sources.add.tile_size"
-        />
-        <FieldSelect
-          label={t("Encoding")}
-          fieldSpec={latest.source_raster_dem.encoding}
-          options={Object.keys(latest.source_raster_dem.encoding.values)}
-          onChange={encoding => this.props.onChange({
-            ...this.props.source,
-            encoding: encoding
-          })}
-          value={this.props.source.encoding || latest.source_raster_dem.encoding.default}
-        />
-      </TileURLSourceEditor>;
-      case "pmtiles_vector": return <PMTilesSourceEditor {...commonProps} />;
-      case "image": return <ImageSourceEditor {...commonProps} />;
-      case "video": return <VideoSourceEditor {...commonProps} />;
-      default: return null;
-    }
+const ModalSourcesTypeEditorInternal: React.FC<ModalSourcesTypeEditorInternalProps> = (props) => {
+  const t = props.t;
+  const commonProps = {
+    source: props.source,
+    onChange: props.onChange,
+    t: props.t,
+    i18n: props.i18n,
+    tReady: props.tReady,
+  };
+  switch(props.mode) {
+    case "geojson_url": return <GeoJSONSourceUrlEditor {...commonProps} />;
+    case "geojson_json": return <GeoJSONSourceFieldJsonEditor {...commonProps} />;
+    case "tilejson_vector": return <TileJSONSourceEditor {...commonProps} />;
+    case "tile_vector": return <TileURLSourceEditor {...commonProps} />;
+    case "tilejson_raster": return <TileJSONSourceEditor {...commonProps} />;
+    case "tile_raster": return <TileURLSourceEditor {...commonProps}>
+      <FieldNumber
+        label={t("Tile Size")}
+        fieldSpec={latest.source_raster.tileSize}
+        onChange={tileSize => props.onChange({
+          ...props.source,
+          tileSize: tileSize
+        })}
+        value={props.source.tileSize || latest.source_raster.tileSize.default}
+        data-wd-key="modal:sources.add.tile_size"
+      />
+    </TileURLSourceEditor>;
+    case "tilejson_raster-dem": return <TileJSONSourceEditor {...commonProps} />;
+    case "tilexyz_raster-dem": return <TileURLSourceEditor {...commonProps}>
+      <FieldNumber
+        label={t("Tile Size")}
+        fieldSpec={latest.source_raster_dem.tileSize}
+        onChange={tileSize => props.onChange({
+          ...props.source,
+          tileSize: tileSize
+        })}
+        value={props.source.tileSize || latest.source_raster_dem.tileSize.default}
+        data-wd-key="modal:sources.add.tile_size"
+      />
+      <FieldSelect
+        label={t("Encoding")}
+        fieldSpec={latest.source_raster_dem.encoding}
+        options={Object.keys(latest.source_raster_dem.encoding.values)}
+        onChange={encoding => props.onChange({
+          ...props.source,
+          encoding: encoding
+        })}
+        value={props.source.encoding || latest.source_raster_dem.encoding.default}
+      />
+    </TileURLSourceEditor>;
+    case "pmtiles_vector": return <PMTilesSourceEditor {...commonProps} />;
+    case "image": return <ImageSourceEditor {...commonProps} />;
+    case "video": return <VideoSourceEditor {...commonProps} />;
+    default: return null;
   }
-}
+};
 
 export const ModalSourcesTypeEditor = withTranslation()(ModalSourcesTypeEditorInternal);