Allow style function to return a style

src/ol/feature.js

@@ -290,7 +290,8 @@ ol.Feature.prototype.setGeometryName = function(name) {
  * resolution. The `this` keyword inside the function references the
  * {@link ol.Feature} to be styled.
  *
- * @typedef {function(this: ol.Feature, number): Array.<ol.style.Style>}
+ * @typedef {function(this: ol.Feature, number):
+ *     (ol.style.Style|Array.<ol.style.Style>)}
  * @api stable
  */
 ol.FeatureStyleFunction;

src/ol/renderer/canvas/canvasvectorlayerrenderer.js

@@ -321,7 +321,8 @@ ol.renderer.canvas.VectorLayer.prototype.prepareFrame =
  * @param {ol.Feature} feature Feature.
  * @param {number} resolution Resolution.
  * @param {number} pixelRatio Pixel ratio.
- * @param {Array.<ol.style.Style>} styles Array of styles
+ * @param {(ol.style.Style|Array.<ol.style.Style>)} styles The style or array of
+ *     styles.
  * @param {ol.render.canvas.ReplayGroup} replayGroup Replay group.
  * @return {boolean} `true` if an image is loading.
  */
@@ -330,12 +331,19 @@ ol.renderer.canvas.VectorLayer.prototype.renderFeature =
   if (!styles) {
     return false;
   }
-  var i, ii, loading = false;
+  var loading = false;
-  for (i = 0, ii = styles.length; i < ii; ++i) {
+  if (goog.isArray(styles)) {
+    for (var i = 0, ii = styles.length; i < ii; ++i) {
       loading = ol.renderer.vector.renderFeature(
           replayGroup, feature, styles[i],
           ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
           this.handleStyleImageChange_, this) || loading;
     }
+  } else {
+    loading = ol.renderer.vector.renderFeature(
+        replayGroup, feature, styles,
+        ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
+        this.handleStyleImageChange_, this) || loading;
+  }
   return loading;
 };

src/ol/renderer/canvas/canvasvectortilelayerrenderer.js

@@ -201,13 +201,20 @@ ol.renderer.canvas.VectorTileLayer.prototype.createReplayGroup = function(tile,
    */
   function renderFeature(feature) {
     var styles;
-    if (feature.getStyleFunction()) {
+    var styleFunction = feature.getStyleFunction();
+    if (styleFunction) {
       goog.asserts.assertInstanceof(feature, ol.Feature, 'Got an ol.Feature');
-      styles = feature.getStyleFunction().call(feature, resolution);
+      styles = styleFunction.call(feature, resolution);
-    } else if (layer.getStyleFunction()) {
+    } else {
-      styles = layer.getStyleFunction()(feature, resolution);
+      styleFunction = layer.getStyleFunction();
+      if (styleFunction) {
+        styles = styleFunction(feature, resolution);
+      }
     }
     if (styles) {
+      if (!goog.isArray(styles)) {
+        styles = [styles];
+      }
       var dirty = this.renderFeature(feature, squaredTolerance, styles,
           replayGroup);
       this.dirty_ = this.dirty_ || dirty;
@@ -423,7 +430,8 @@ ol.renderer.canvas.VectorTileLayer.prototype.prepareFrame =
 /**
  * @param {ol.Feature|ol.render.Feature} feature Feature.
  * @param {number} squaredTolerance Squared tolerance.
- * @param {Array.<ol.style.Style>} styles Array of styles
+ * @param {(ol.style.Style|Array.<ol.style.Style>)} styles The style or array of
+ *     styles.
  * @param {ol.render.canvas.ReplayGroup} replayGroup Replay group.
  * @return {boolean} `true` if an image is loading.
  */
@@ -432,11 +440,17 @@ ol.renderer.canvas.VectorTileLayer.prototype.renderFeature =
   if (!styles) {
     return false;
   }
-  var i, ii, loading = false;
+  var loading = false;
-  for (i = 0, ii = styles.length; i < ii; ++i) {
+  if (goog.isArray(styles)) {
+    for (var i = 0, ii = styles.length; i < ii; ++i) {
       loading = ol.renderer.vector.renderFeature(
           replayGroup, feature, styles[i], squaredTolerance,
           this.handleStyleImageChange_, this) || loading;
     }
+  } else {
+    loading = ol.renderer.vector.renderFeature(
+        replayGroup, feature, styles, squaredTolerance,
+        this.handleStyleImageChange_, this) || loading;
+  }
   return loading;
 };

src/ol/renderer/dom/domvectorlayerrenderer.js

@@ -329,7 +329,8 @@ ol.renderer.dom.VectorLayer.prototype.prepareFrame =
  * @param {ol.Feature} feature Feature.
  * @param {number} resolution Resolution.
  * @param {number} pixelRatio Pixel ratio.
- * @param {Array.<ol.style.Style>} styles Array of styles
+ * @param {(ol.style.Style|Array.<ol.style.Style>)} styles The style or array of
+ *     styles.
  * @param {ol.render.canvas.ReplayGroup} replayGroup Replay group.
  * @return {boolean} `true` if an image is loading.
  */
@@ -338,12 +339,19 @@ ol.renderer.dom.VectorLayer.prototype.renderFeature =
   if (!styles) {
     return false;
   }
-  var i, ii, loading = false;
+  var loading = false;
-  for (i = 0, ii = styles.length; i < ii; ++i) {
+  if (goog.isArray(styles)) {
+    for (var i = 0, ii = styles.length; i < ii; ++i) {
       loading = ol.renderer.vector.renderFeature(
           replayGroup, feature, styles[i],
           ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
           this.handleStyleImageChange_, this) || loading;
     }
+  } else {
+    loading = ol.renderer.vector.renderFeature(
+        replayGroup, feature, styles,
+        ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
+        this.handleStyleImageChange_, this) || loading;
+  }
   return loading;
 };

src/ol/renderer/webgl/webglvectorlayerrenderer.js

@@ -297,7 +297,8 @@ ol.renderer.webgl.VectorLayer.prototype.prepareFrame =
  * @param {ol.Feature} feature Feature.
  * @param {number} resolution Resolution.
  * @param {number} pixelRatio Pixel ratio.
- * @param {Array.<ol.style.Style>} styles Array of styles
+ * @param {(ol.style.Style|Array.<ol.style.Style>)} styles The style or array of
+ *     styles.
  * @param {ol.render.webgl.ReplayGroup} replayGroup Replay group.
  * @return {boolean} `true` if an image is loading.
  */
@@ -306,12 +307,19 @@ ol.renderer.webgl.VectorLayer.prototype.renderFeature =
   if (!styles) {
     return false;
   }
-  var i, ii, loading = false;
+  var loading = false;
-  for (i = 0, ii = styles.length; i < ii; ++i) {
+  if (goog.isArray(styles)) {
+    for (var i = 0, ii = styles.length; i < ii; ++i) {
       loading = ol.renderer.vector.renderFeature(
           replayGroup, feature, styles[i],
           ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
           this.handleStyleImageChange_, this) || loading;
     }
+  } else {
+    loading = ol.renderer.vector.renderFeature(
+        replayGroup, feature, styles,
+        ol.renderer.vector.getSquaredTolerance(resolution, pixelRatio),
+        this.handleStyleImageChange_, this) || loading;
+  }
   return loading;
 };

src/ol/style/style.js

@@ -199,7 +199,7 @@ ol.style.Style.prototype.setZIndex = function(zIndex) {
  * {@link ol.style.Style}. This way e.g. a vector layer can be styled.
  *
  * @typedef {function((ol.Feature|ol.render.Feature), number):
- *     Array.<ol.style.Style>}
+ *     (ol.style.Style|Array.<ol.style.Style>)}
  * @api
  */
 ol.style.StyleFunction;