Give feature overlays a style option

src/ol/featureoverlay.js

@@ -10,6 +10,7 @@ goog.require('ol.CollectionEventType');
 goog.require('ol.Feature');
 goog.require('ol.feature');
 goog.require('ol.render.EventType');
+goog.require('ol.style.Style');
 
 
 
@@ -52,11 +53,35 @@ ol.FeatureOverlay = function(opt_options) {
    */
   this.postComposeListenerKey_ = null;
 
+  /**
+   * @type {ol.feature.StyleFunction}
+   */
+  var styleFunction;
+  if (goog.isDef(options.style)) {
+    if (goog.isFunction(options.style)) {
+      styleFunction = /** @type {ol.feature.StyleFunction} */ (options.style);
+    } else {
+      /**
+       * @type {Array.<ol.style.Style>}
+       */
+      var styles;
+      if (goog.isArray(options.style)) {
+        styles = options.style;
+      } else {
+        goog.asserts.assertInstanceof(options.style, ol.style.Style);
+        styles = [options.style];
+      }
+      styleFunction = function(feature, resolution) {
+        return styles;
+      };
+    }
+  }
+
   /**
    * @private
    * @type {ol.feature.StyleFunction|undefined}
    */
-  this.styleFunction_ = undefined;
+  this.styleFunction_ = styleFunction;
 
   if (goog.isDef(options.features)) {
     if (goog.isArray(options.features)) {
@@ -69,10 +94,6 @@ ol.FeatureOverlay = function(opt_options) {
     this.setFeatures(new ol.Collection());
   }
 
-  if (goog.isDef(options.styleFunction)) {
-    this.setStyleFunction(options.styleFunction);
-  }
-
   if (goog.isDef(options.map)) {
     this.setMap(options.map);
   }