webapps/qooxdoo-0.6.5-sdk/frontend/framework/source/class/qx/io/image/PreloaderSystem.js

   1 /* ************************************************************************
   2
   3    qooxdoo - the new era of web development
   4
   5    http://qooxdoo.org
   6
   7    Copyright:
   8      2004-2007 1&1 Internet AG, Germany, http://www.1and1.org
   9
  10    License:
  11      LGPL: http://www.gnu.org/licenses/lgpl.html
  12      EPL: http://www.eclipse.org/org/documents/epl-v10.php
  13      See the LICENSE file in the project's top-level directory for details.
  14
  15    Authors:
  16      * Sebastian Werner (wpbasti)
  17      * Andreas Ecker (ecker)
  18
  19 ************************************************************************ */
  20
  21 /* ************************************************************************
  22
  23 #module(ui_core)
  24
  25 ************************************************************************ */
  26
  27 /**
  28  * @event completed {qx.event.type.Event}
  29  */
  30 qx.OO.defineClass("qx.io.image.PreloaderSystem", qx.core.Target,
  31 function(vPreloadList, vCallBack, vCallBackScope)
  32 {
  33   qx.core.Target.call(this);
  34
  35   this._list = vPreloadList;
  36
  37   // Create timer
  38   this._timer = new qx.client.Timer(this.getSetting("timeout"));
  39   this._timer.addEventListener("interval", this._oninterval, this);
  40
  41   // If we use the compact syntax, automatically add an event listeners and start the loading process
  42   if (vCallBack)
  43   {
  44     this.addEventListener("completed", vCallBack, vCallBackScope || null);
  45     this.start();
  46   }
  47 });
  48
  49 qx.Proto._stopped = false;
  50
  51
  52
  53 /*
  54 ---------------------------------------------------------------------------
  55   DEFAULT SETTINGS
  56 ---------------------------------------------------------------------------
  57 */
  58
  59 qx.Settings.setDefault("timeout", 3000);
  60
  61
  62
  63
  64
  65 /*
  66 ---------------------------------------------------------------------------
  67   USER ACCESS
  68 ---------------------------------------------------------------------------
  69 */
  70
  71 qx.Proto.start = function()
  72 {
  73   if (qx.lang.Object.isEmpty(this._list))
  74   {
  75     this.createDispatchEvent("completed");
  76     return;
  77   }
  78
  79   for (var vSource in this._list)
  80   {
  81     var vPreloader = qx.manager.object.ImagePreloaderManager.getInstance().create(qx.manager.object.AliasManager.getInstance().resolvePath(vSource));
  82
  83     if (vPreloader.isErroneous() || vPreloader.isLoaded())
  84     {
  85       delete this._list[vSource];
  86     }
  87     else
  88     {
  89       vPreloader._origSource = vSource;
  90
  91       vPreloader.addEventListener("load", this._onload, this);
  92       vPreloader.addEventListener("error", this._onerror, this);
  93     }
  94   }
  95
  96   // Initial check
  97   this._check();
  98 }
  99
 100
 101
 102
 103
 104 /*
 105 ---------------------------------------------------------------------------
 106   EVENT LISTENERS
 107 ---------------------------------------------------------------------------
 108 */
 109
 110 qx.Proto._onload = function(e)
 111 {
 112   delete this._list[e.getTarget()._origSource];
 113   this._check();
 114 }
 115
 116 qx.Proto._onerror = function(e)
 117 {
 118   delete this._list[e.getTarget()._origSource];
 119   this._check();
 120 }
 121
 122 qx.Proto._oninterval = function(e)
 123 {
 124   this.error("Could not preload: " + qx.lang.Object.getKeysAsString(this._list));
 125
 126   this._stopped = true;
 127   this._timer.stop();
 128
 129   this.createDispatchEvent("completed");
 130 }
 131
 132
 133
 134
 135
 136
 137 /*
 138 ---------------------------------------------------------------------------
 139   CHECK
 140 ---------------------------------------------------------------------------
 141 */
 142
 143 qx.Proto._check = function()
 144 {
 145   if (this._stopped) {
 146     return;
 147   }
 148
 149   // this.debug("Check: " + qx.lang.Object.getKeysAsString(this._list));
 150
 151   if (qx.lang.Object.isEmpty(this._list))
 152   {
 153     this._timer.stop();
 154     this.createDispatchEvent("completed");
 155   }
 156   else
 157   {
 158     // Restart timer for timeout
 159     this._timer.restart();
 160   }
 161 }
 162
 163
 164
 165
 166
 167
 168 /*
 169 ---------------------------------------------------------------------------
 170   DISPOSER
 171 ---------------------------------------------------------------------------
 172 */
 173
 174 qx.Proto.dispose = function()
 175 {
 176   if (this.getDisposed()) {
 177     return true;
 178   }
 179
 180   this._list = null;
 181
 182   if (this._timer)
 183   {
 184     this._timer.dispose();
 185     this._timer = null;
 186   }
 187
 188   return qx.core.Target.prototype.dispose.call(this);
 189 }