cocos2d extend touch area from a button

Question

I got some radiobuttons but the toucharea is to small. The toucharea depends on the image size. Is there an elegant way to extend the touch area with cocos2d without using a bigger image or make my own touch areas with cgrect? setContentSize do what I want. Unfortunately the image moves to the left bottom corner of the contentsize. Set the anchorpoint moves the contentsize around but the image stays in the left bottom corner.

    CCMenuItem* pickEasy = [CCMenuItemImage itemFromNormalImage:@"radiobutton_off.png" selectedImage:@"radiobutton_on.png" target:self selector:@selector(pickEasyTapped:)];
    pickEasy.position = ccp(ss.width * 0.40, ss.height * 0.78);
    [pickEasy setContentSize:CGSizeMake(50, 50)];

Thanks in advance.

Answer 1

You need to override the rectInPixels method

- (CGRect)rectInPixels
{
CGSize s = [self contentSize];
return CGRectMake(0, 0, s.width, s.height);
}

- (BOOL)containsTouchLocation:(UITouch *)touch
{   
CGPoint p = [self convertTouchToNodeSpace:touch];
CGRect r = [self rectInPixels];
return CGRectContainsPoint(r, p);
}

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event {

NSSet *allTouches = [event allTouches];
for (UITouch *aTouch in allTouches) {

        if ( ![self containsTouchLocation:aTouch] ) return NO;
}

return YES;
}

This just tells the sprite to check that the touch lyes within your altered CGRect

Edit to show CCSprite subclass ---

- (void)onEnter
{
[[CCTouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
[super onEnter];
}

- (void)onExit
{
[[CCTouchDispatcher sharedDispatcher] removeDelegate:self];
[super onExit];
}