Class Ext.ProgressBar

Property   Type          Description
---------- ------------  ----------------------------------------------------------------------
duration   Number        The length of time in milliseconds that the progress bar should
                         run before resetting itself (defaults to undefined, in which case it
                         will run indefinitely until reset is called)
interval   Number        The length of time in milliseconds between each progress update
                         (defaults to 1000 ms)
increment  Number        The number of progress update segments to display within the progress
                         bar (defaults to 10).  If the bar reaches the end and is still
                         updating, it will automatically wrap back to the beginning.
fn         Function      A callback function to execute after the progress bar finishes auto-
                         updating.  The function will be called with no arguments.  This function
                         will be ignored if duration is not specified since in that case the
                         progress bar can only be stopped programmatically, so any required function
                         should be called by the same code after it resets the progress bar.
scope      Object        The scope that is passed to the callback function (only applies when
                         duration and fn are both passed).

var p = new Ext.ProgressBar({
   renderTo: 'my-el'
});

//Wait for 5 seconds, then update the status el (progress bar will auto-reset)
p.wait({
   interval: 100, //bar will move fast!
   duration: 5000,
   increment: 15,
   scope: this,
   fn: function(){
      Ext.fly('status').update('Done!');
   }
});

//Or update indefinitely until some async action completes, then reset manually
p.wait();
myAction.on('complete', function(){
    p.reset();
    Ext.fly('status').update('Done!');
});