add uicomponent inside a sprite - apache-flex

Question

i want to add UIComponent inside a spite. here is the code:
private function make() : void {
var circle : Sprite = new Sprite();
circle.graphics.beginFill(0xFF0000, 0.2);
circle.graphics.drawCircle(0, 0, 20);
var button : Button = new Button();
button.label = "testing...";
var wrapper : UIComponent = new UIComponent();
circle.addChild( button );
wrapper.addChild( circle );
addChild( wrapper );
}
the problem is that button is added, but is not displayed. if i do reversed - add sprite to uicomponent - everything works fine, but this way it doesn't work. i tried to use invalidate functions for button etc... even tried making "circle" as UIMovieClip, but no luck - button is still invisible. also if i simply do "addChild( button );" - it is shown, what the... please help, what i am doing wrong? how can i add a button inside a sprite?

Answer 1

Short answer, you can't. What you CAN do is instead of using Sprite, you use UIComponent for your circle.
The reason for this is that UIComponent has A LOT of code that changes how it behaves, including how to add and layout children. You could essentially take the same code to a Sprite since UIComponent does extend it, however that would be VERY redundant. This works great for me:
private function make() : void {
var circle : UIComponent= new UIComponent();
circle.graphics.beginFill(0xFF0000, 0.2);
circle.graphics.drawCircle(0, 0, 20);
var button : Button = new Button();
button.label = "testing...";
var wrapper : UIComponent = new UIComponent();
circle.addChild( button );
wrapper.addChild( circle );
addChild( wrapper );
}

Answer 2

Unfortunately, in order to use Sprite the way you are trying to do it, you would have to extend Sprite and implement IUIComponent.
Taken from the Flex 3 Language Reference:
Note: While the child argument to the
method is specified as of type
DisplayObject, the argument must
implement the IUIComponent interface
to be added as a child of a container.
All Flex components implement this
interface.
Sprite does not implement IUIComponent, so you are experiencing a pretty typical issue. UIComponent's don't typically have speed issues when compared to Sprites, so I would recommend just drawing on your UIComponent.
As stated before, you /could/ extend Sprite to implement IUIComponent, but it's a pain.
Hope this helps!