In my previous post "Custom Item Renderer for Tree Control in Flex" I demonstrated how you can modify the default flex Tree control appearance. Now with the appearance changed we need to modify the default behavior of the tree control as well. Suppose you want to throw some custom event from the custom item renderer. One example will be to bubble a click event to the parent application from the custom item renderer telling that it was generated from the customized object we added in the item renderer i.e. in our case an image which we added to the default tree nodes. For example i want something to happen when a user click on the image (the blue question mark) and not when he clicks on the node. If you look at the code in method createChildren() override protected function createChildren(): void { super .createChildren(); customItem= new Image(); customItem.source = 'Images/helpIcon.jpg' ; customItem.addEventListener(MouseEvent.CLICK,helpEvent,true); ...