Multitouch multiple touch points confusion

Question

I am trying to implement multiple touch points for the first time. I'm testing on a Samsung Galaxy Tab 2 7.0; if I do device debugging over USB, AIR reports that the device supports 2 touch points and touch events are supported.

The app I'm working on is in the early stages, so there's not much going on at the moment. I have two SimpleButtons that I'm trying to set up so the user can press both of them at the same time, but I can't get it to work right. If I hold the first button and then press the second button, the first button stays pressed and the second button doesn't recognize a press (the SimpleButton doesn't even change its background to the pressed state). If I hold the second button and then press the first button, the first button does nothing, and the second button is released (both in my code and visually).

public function enableButtons():void {

Multitouch.inputMode = MultitouchInputMode.TOUCH_POINT;

trace("supportsTouchEvents:" + Multitouch.supportsTouchEvents);

button1.addEventListener(TouchEvent.TOUCH_BEGIN, onHoldButton, false, 0, true);

button2.addEventListener(TouchEvent.TOUCH_BEGIN, onHoldButton, false, 0, true);

}

private function onHoldButton(event:TouchEvent):void {

trace("HOLD BUTTON " + event.target.name);

var button:SimpleButton = event.currentTarget as SimpleButton;

button.removeEventListener(TouchEvent.TOUCH_BEGIN, onHoldButton);

button.addEventListener(TouchEvent.TOUCH_END, onReleaseButton, false, 0, true);

button.addEventListener(TouchEvent.TOUCH_OUT, onReleaseButton, false, 0, true);

}

private function onReleaseButton(event:TouchEvent):void {

trace("RELEASE BUTTON" + event.target.name);

var button:SimpleButton = event.currentTarget as SimpleButton;

button.addEventListener(TouchEvent.TOUCH_BEGIN, onHoldButton, false, 0, true);

button.removeEventListener(TouchEvent.TOUCH_END, onReleaseButton);

button.removeEventListener(TouchEvent.TOUCH_OUT, onReleaseButton);

}

Am I doing something wrong here? Do SimpleButtons not support multitouch?

Mark.fromOP · Accepted Answer

"With mouse events you never have to worry about multiple clicks at once since you only have the one mouse. "

I know, I'm just saying the code

var button:SimpleButton = event.currentTarget as SimpleButton;

button.removeEventListener(TouchEvent.TOUCH_BEGIN, onHoldButton);

will not prevent the events from working correctly, as the TOUCH_BEGIN event is only removed from the button that is already touched, not affecting the button that wasn't touched yet.

Here's the answer: SimpleButton does NOT support Multitouch. I changed the buttons to a custom class and the problem went away. I usually do code my own components rather than using Adobe's components, and I've even done my own two-state buttons in the past, but for this project I had assumed SimpleButton would be adequate. Apparently not!

Thank you for your assistance, I probably would have wasted more hours before trying a different button class if you hadn't said SimpleButton works poorly with touch events. Would you like to add the note that SimpleButton does not support Multitouch to your post so anyone else who has this problem will see the answer more easily?

Should a bug report be filed about SimpleButton not supporting Multitouch?

Cant seem to edit my post, so here is the short of it based on your discoveries.

Here's the answer: SimpleButton does NOT support Multitouch.

You can mark this or your own reply as correct.

Colin Holgate · Answer

You’re using TOUCH_OUT. Might the press on the second button be seen as a touch out for the first button. What happens if you don’t use that listener?

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