third_party/WebKit/Source/devtools/front_end/ui/ThrottledWidget.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * @constructor
   7  * @extends {WebInspector.Widget}
   8  */
   9 WebInspector.ThrottledWidget = function()
  10 {
  11     WebInspector.Widget.call(this);
  12     this._updateThrottler = new WebInspector.Throttler(100);
  13     this._updateWhenVisible = false;
  14 }
  15
  16 WebInspector.ThrottledWidget.prototype = {
  17     /**
  18      * @protected
  19      * @return {!Promise.<?>}
  20      */
  21     doUpdate: function()
  22     {
  23         return Promise.resolve();
  24     },
  25
  26     update: function()
  27     {
  28         this._updateWhenVisible = !this.isShowing();
  29         if (this._updateWhenVisible)
  30             return;
  31         this._updateThrottler.schedule(innerUpdate.bind(this));
  32
  33         /**
  34          * @this {WebInspector.ThrottledWidget}
  35          * @return {!Promise.<?>}
  36          */
  37         function innerUpdate()
  38         {
  39             if (this.isShowing()) {
  40                 return this.doUpdate();
  41             } else {
  42                 this._updateWhenVisible = true;
  43                 return Promise.resolve();
  44             }
  45         }
  46     },
  47
  48     /**
  49      * @override
  50      */
  51     wasShown: function()
  52     {
  53         WebInspector.Widget.prototype.wasShown.call(this);
  54         if (this._updateWhenVisible)
  55             this.update();
  56     },
  57
  58     __proto__: WebInspector.Widget.prototype
  59 }