Question

I’ve just discovered a bug in my app, it looks like a Flash player bug, i would like to know if anyone has found a workaround or something.

I’ve some radio buttons groups in my app. If I press the arrow keys while holding the spacebar pressed, it ends up triggering

  TypeError: Error #1009: Cannot access a property or method of a null object reference.
    at fl.controls::LabelButton/drawIcon()
    at fl.controls::LabelButton/draw()
    at fl.controls::RadioButton/draw()
    at fl.core::UIComponent/callLaterDispatcher()

If found this thread that describes my same situation.
Do you think there’s any workaround for this? Is it really a flash bug?

Answer 1

So, I’ve investigated this problem and found, that there is an error in standard fl components. It is not only about RadioButton. If you hold SpaceBar and then switch current UI element by clicking “TAB” button – you will receive similar error.

To solve it, you should fix source of the component: in class LabelButton, method keyUpHandler replace code

setMouseState(oldMouseState);

with

if (oldMouseState!==null) {
    setMouseState(oldMouseState);
}

and add override:

override protected function focusOutHandler(event:FocusEvent):void {
    if (oldMouseState) {
        keyUpHandler(new KeyboardEvent(KeyboardEvent.KEY_UP, true, true, 0, Keyboard.SPACE));
    }

    super.focusOutHandler(event);
}

If you don’t know, how you can do it:

1. just copy Adobe Flash CS5 install folder\Common\Configuration\Component Source\ActionScript 3.0\User Interface\fl\controls\LabelButton.as to another directory with the same package structure \fl\controls\LabelButton.as

2. then you need include this duplicated structure to project.

It is not very good way, but in this case it really fixes this error. BTW, I’ll send it to Adobe.