Panel listener when a window is opened inside of it - extjs4.1

Question

I have a Panel which acts as a desktop. When a button is clicked a window is opened up inside the panel. I set the following in the config:
var win = Ext.create('window', {
renderTo : currentPanel.getLayout().getTarget(),
constrain : true
});
win.show();
So my window is being open and constrained in the main panel. I want the panel to listen for when any window is open inside of it so I can monitor it. Are there any listener that will do this? I tried 'add' and 'added' but the window has to be added to the panel via:
panel.add(window);
But in my case I'm not adding it to the container, but I'm opening it and constraining it to my container using the renderTo.

Answer 1

What I would do is create a subclass of panel for your desktop and a subclass of window for your windows. Add a 'windowOpened' listener to your custom panel, and fire this event from your custom window's 'show' listener.
Something like this:
DesktopPanel.js
Ext.define('App.view.DesktopPanel', {
extend: 'Ext.panel.Panel',
alias: 'widget.desktoppanel',
initComponent: function() {
this.callParent();
this.addListener('windowOpened', function(newWindow){
//Do whatever it is you want to do here
});
}
});
DesktopWindow.js
Ext.define('App.view.DesktopWindow', {
extend: 'Ext.window.Window',
alias: 'widget.desktopwindow',
constrain: true,
initComponent: function() {
this.renderTo = this.ownerPanel.getLayout().getTarget();
this.callParent();
this.addListener('show', function(){
this.ownerPanel.fireEvent('windowOpened',this);
});
}
});
Then your code would be something like this:
var win = Ext.create('App.view.DesktopWindow', {
ownerPanel: MyDesktop, //an instance of 'DesktopPanel'
});
win.show();