title: EXTJS - Load Mask
body: <p>I want to present the source code, which is taken from inside a div with jQuery, inside an <code>Ext.Window</code>. I have managed to do that, but my problem is that sometimes the source code is huge, since it contains encoded images and the <code>Ext.Window</code> takes some time to appear in the screen after it is triggered via click event. I would like to present the <code>Ext.Window</code> but with a loading icon until the data is ready.</p>
  
  <pre><code>win = new Ext.Window ({
      title:'Source Code',
      width:800,
      height:300,
      items: [{
          xtype : 'textarea',
          readOnly: true,
          value: sourceCode
      }]
  });
  win.show();
  </code></pre>