Add new maxDelta property to MouseWheelZoom constructor

src/ol/interaction/MouseWheelZoom.js

@@ -8,13 +8,6 @@ import Interaction, {zoomByDelta} from './Interaction.js';
 import {clamp} from '../math.js';
 
 
-/**
- * Maximum mouse wheel delta.
- * @type {number}
- */
-const MAX_DELTA = 1;
-
-
 /**
  * @enum {string}
  */
@@ -30,6 +23,7 @@ export const Mode = {
  * takes an {@link module:ol/MapBrowserEvent~MapBrowserEvent} and returns a
  * boolean to indicate whether that event should be handled. Default is
  * {@link module:ol/events/condition~always}.
+ * @property {number} [maxDelta=1] Maximum mouse wheel delta.
  * @property {number} [duration=250] Animation duration in milliseconds.
  * @property {number} [timeout=80] Mouse wheel timeout duration in milliseconds.
  * @property {boolean} [useAnchor=true] Enable zooming using the mouse's
@@ -65,6 +59,12 @@ class MouseWheelZoom extends Interaction {
      */
     this.lastDelta_ = 0;
 
+    /**
+     * @private
+     * @type {number}
+     */
+    this.maxDelta_ = options.maxDelta !== undefined ? options.maxDelta : 1;
+
     /**
      * @private
      * @type {number}
@@ -235,8 +235,7 @@ class MouseWheelZoom extends Interaction {
     if (view.getAnimating()) {
       view.cancelAnimations();
     }
-    const maxDelta = MAX_DELTA;
+    const delta = clamp(this.totalDelta_, -this.maxDelta_, this.maxDelta_);
-    const delta = clamp(this.totalDelta_, -maxDelta, maxDelta);
     zoomByDelta(view, -delta, this.lastAnchor_, this.duration_);
     this.mode_ = undefined;
     this.totalDelta_ = 0;