third_party/WebKit/Source/devtools/front_end/ui/ZoomManager.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.Object}
   8  * @param {!Window} window
   9  * @param {!InspectorFrontendHostAPI} frontendHost
  10  */
  11 WebInspector.ZoomManager = function(window, frontendHost)
  12 {
  13     this._frontendHost = frontendHost;
  14     this._zoomFactor = this._frontendHost.zoomFactor();
  15     window.addEventListener("resize", this._onWindowResize.bind(this), true);
  16 };
  17
  18 WebInspector.ZoomManager.Events = {
  19     ZoomChanged: "ZoomChanged"
  20 };
  21
  22 WebInspector.ZoomManager.prototype = {
  23     /**
  24      * @return {number}
  25      */
  26     zoomFactor: function()
  27     {
  28         return this._zoomFactor;
  29     },
  30
  31     /**
  32      * @param {number} value
  33      * @return {number}
  34      */
  35     cssToDIP: function(value)
  36     {
  37         return value * this._zoomFactor;
  38     },
  39
  40     /**
  41      * @param {number} valueDIP
  42      * @return {number}
  43      */
  44     dipToCSS: function(valueDIP)
  45     {
  46         return valueDIP / this._zoomFactor;
  47     },
  48
  49     _onWindowResize: function()
  50     {
  51         var oldZoomFactor = this._zoomFactor;
  52         this._zoomFactor = this._frontendHost.zoomFactor();
  53         if (oldZoomFactor !== this._zoomFactor)
  54             this.dispatchEventToListeners(WebInspector.ZoomManager.Events.ZoomChanged, {from: oldZoomFactor, to: this._zoomFactor});
  55     },
  56
  57     __proto__: WebInspector.Object.prototype
  58 };
  59
  60 /**
  61  * @type {!WebInspector.ZoomManager}
  62  */
  63 WebInspector.zoomManager;