Removing sprite in Cocos2d causing a crash

Question

I have a method set up to remove a sprite on touch, I have several sprites which need to be removed but I have only show one below:

-(void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event { 

    ....

    if(CGRectContainsPoint(goalItem.boundingBox, touch)) {
          [self removeChild:goalItem cleanup:YES];
    }

    ....

}

Where goalItem is a CCSprite declared in the header. Basically this causes a crash once the ccTouchEnded method is called again.

I presume this is because the method is looking for goalItem when it has already been removed but I'm not sure.

What is the best way of safely removing a sprite and making sure the pointer doesn't get confused?

I'm very new to cocos2d and objective-c so I'm sure its probably quite a fundamental mistake :/

UPDATE:

I fixed it by creating this method:

-(BOOL)checkForGoalSprite:(CGPoint)point {
if([self.children containsObject:goalItem]){
    if(CGRectContainsPoint(goalItem.boundingBox, point)){
        return YES; 
    }else {
        return NO;
    }
}else{
    return NO;  
}

}

So it ccTouchEnded reads:

-(void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event { 

....

if([self checkForGoalSprite:touch]) {
      [self removeChild:goalItem cleanup:YES];
}

....

}

I'm sure theres a better way...

UPDATE:

I was making the basic error of using if else statements where I could have used if statements, forcing ccTouchEnded to pick only one option.

Any crash log?... Please share the output from console when this crash happens. — Tayyab

badgerr badgerr · Accepted Answer · 2011-03-31T13:08:19

You are "cleaning up" the sprite, so the pointer is likely to be garbage after this point. I do it by checking the CCSprite object for != nil, then setting it to nil after the removal:

-(void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event { 

    ....

    if(goalItem != nil)
    {
        if(CGRectContainsPoint(goalItem.boundingBox, touch)) {
              [self removeChild:goalItem cleanup:YES];
              goalItem = nil;
        }
    }

    ....

}

Removing sprite in Cocos2d causing a crash

2 Answers