Move ol.ZOOMSLIDER_ANIMATION_DURATION const to a constructor option

externs/olx.js

@@ -1435,6 +1435,7 @@ olx.control.ZoomOptions.prototype.target;
 
 /**
  * @typedef {{className: (string|undefined),
+ *     duration: (number|undefined),
  *     maxResolution: (number|undefined),
  *     minResolution: (number|undefined),
  *     render: (function(ol.MapEvent)|undefined)}}
@@ -1451,6 +1452,14 @@ olx.control.ZoomSliderOptions;
 olx.control.ZoomSliderOptions.prototype.className;
 
 
+/**
+ * Animation duration in milliseconds. Default is `200`.
+ * @type {number|undefined}
+ * @api
+ */
+olx.control.ZoomSliderOptions.prototype.duration;
+
+
 /**
  * Maximum resolution.
  * @type {number|undefined}

src/ol/control/zoomslidercontrol.js

@@ -14,7 +14,6 @@ goog.require('goog.fx.Dragger.EventType');
 goog.require('goog.math');
 goog.require('goog.math.Rect');
 goog.require('goog.style');
-goog.require('ol');
 goog.require('ol.Size');
 goog.require('ol.ViewHint');
 goog.require('ol.animation');
@@ -73,6 +72,12 @@ ol.control.ZoomSlider = function(opt_options) {
    */
   this.sliderInitialized_ = false;
 
+  /**
+   * @private
+   * @type {number}
+   */
+  this.duration_ = goog.isDef(options.duration) ? options.duration : 200;
+
   var className = goog.isDef(options.className) ?
       options.className : 'ol-zoomslider';
   var thumbElement = goog.dom.createDom(goog.dom.TagName.DIV,
@@ -203,7 +208,7 @@ ol.control.ZoomSlider.prototype.handleContainerClick_ = function(browserEvent) {
       'currentResolution should be defined');
   map.beforeRender(ol.animation.zoom({
     resolution: currentResolution,
-    duration: ol.ZOOMSLIDER_ANIMATION_DURATION,
+    duration: this.duration_,
     easing: ol.easing.easeOut
   }));
   var relativePosition = this.getRelativePosition_(
@@ -250,7 +255,7 @@ ol.control.ZoomSlider.prototype.handleDraggerEnd_ = function(event) {
       'this.currentResolution_ should be defined');
   map.beforeRender(ol.animation.zoom({
     resolution: this.currentResolution_,
-    duration: ol.ZOOMSLIDER_ANIMATION_DURATION,
+    duration: this.duration_,
     easing: ol.easing.easeOut
   }));
   var resolution = view.constrainResolution(this.currentResolution_);

src/ol/ol.js

@@ -239,12 +239,6 @@ ol.WEBGL_MAX_TEXTURE_SIZE; // value is set in `ol.has`
 ol.WEBGL_EXTENSIONS; // value is set in `ol.has`
 
 
-/**
- * @define {number} Zoom slider animation duration.
- */
-ol.ZOOMSLIDER_ANIMATION_DURATION = 200;
-
-
 /**
  * Inherit the prototype methods from one constructor into another.
  *