We are trying to prevent unnecessary rendering and therefor just want to hide and show a window containing a quite huge grid.

The window itself is constrained to the viewport by calling 

```
App.Instance.getViewPort().add(scope.myWindowRef = Ext.create('Ext.Window'),{ 
    constrainHeader: true 
    /* and the rest of the cfg */ 
});
scope.myWindowRef.on('close',function(win){ win.hide(); win.caller.enable(); return false; });

```

We have a button listeners inside the controller which should now `show` an `hide` window

```
onOpenWin: function(button) {
    button.disable();
    var scope = this,
        win = scope.myWindowRef;
    win.caller = button;
    win.show();
}

```