Make mouse wheel zoom animation duration configurable

src/objectliterals.jsdoc

@@ -313,6 +313,11 @@
  * @property {number|undefined} delta The amount to zoom on each key press.
  */
 
+/**
+ * @typedef {Object} ol.interaction.MouseWheelZoomOptions
+ * @property {number|undefined} duration Animation duration. Default is 250ms.
+ */
+
 /**
  * @typedef {Object} ol.interaction.SelectOptions
  * @property {ol.interaction.ConditionType|undefined} addCondition A conditional

src/ol/interaction/mousewheelzoominteraction.js

@@ -10,12 +10,6 @@ goog.require('ol.Coordinate');
 goog.require('ol.interaction.Interaction');
 
 
-/**
- * @define {number} Animation duration.
- */
-ol.interaction.MOUSEWHEELZOOM_ANIMATION_DURATION = 250;
-
-
 /**
  * @define {number} Maximum delta.
  */
@@ -33,8 +27,11 @@ ol.interaction.MOUSEWHEELZOOM_TIMEOUT_DURATION = 80;
  * Allows the user to zoom the map by scrolling the mouse wheel.
  * @constructor
  * @extends {ol.interaction.Interaction}
+ * @param {ol.interaction.MouseWheelZoomOptions=} opt_options Options.
  */
-ol.interaction.MouseWheelZoom = function() {
+ol.interaction.MouseWheelZoom = function(opt_options) {
+
+  var options = goog.isDef(opt_options) ? opt_options : {};
 
   goog.base(this);
 
@@ -44,6 +41,12 @@ ol.interaction.MouseWheelZoom = function() {
    */
   this.delta_ = 0;
 
+  /**
+   * @private
+   * @type {number}
+   */
+  this.duration_ = goog.isDef(options.duration) ? options.duration : 250;
+
   /**
    * @private
    * @type {?ol.Coordinate}
@@ -113,7 +116,7 @@ ol.interaction.MouseWheelZoom.prototype.doZoom_ = function(map) {
 
   map.requestRenderFrame();
   ol.interaction.Interaction.zoomByDelta(map, view, -delta, this.lastAnchor_,
-      ol.interaction.MOUSEWHEELZOOM_ANIMATION_DURATION);
+      this.duration_);
 
   this.delta_ = 0;
   this.lastAnchor_ = null;