cocos2d 3.0 how to handle touch swallowing with priority - ios

Question

Since CCTargetedTouchDelegate has been removed since cocos2d 3.0, I would like to know how can i handle touch swallowing stuff?
I have a small sprite on top of a canvas node(layer in 2.x) and need to set the priority of the sprite higher than the canvas. When a user touches within the sprites bounding box, the touch is swallowed, otherwise the canvas will respond to it.

Answer 1

In cocos2d 3.0 touches are handled in reverse z-order order. This means that if your sprite is rendered on top of the canvas node it should already receive touch notification first, and has a chance to swallow it.
However, to receive and swallow the touch by the sprite you should follow these steps:
Create a separate class for your sprite and inherit it from
CCSprite.
Set self.userInteractionEnabled to YES in the init method
if this class.
Add empty touchBegan: method.
This will swallow the touch, because without calling [super touchBegan:...] in the touchBegan: method, you won't pass it to the underlying nodes.
The default implementation of CCSprite (and all the way up to CCNode) calls the [super touchBegan:...], this is why you need to create a subclass and override this behaviour.
In case you do need to pass touches to underlying nodes in some cases, you can write something like this:
-(void)touchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
if (_passToUnderlyingNode == YES)
{
//passed to canvas node
[super touchBegan:touch withEvent:event];
}
else
{
//swallowed
}
}