Question

I’m trying to create a extended CCSprite class that can detect touches. I have done some research and discovered an example at http://anny.fm/c/iphone/cocos2d/TouchableSprite/ which was created by Anny in this forum thread http://www.cocos2d-iphone.org/forum/topic/3196 (last post).

Using this I have setup my class like so:

Header

#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface PianoKey : CCSprite <CCTargetedTouchDelegate> {

}

-(BOOL) tsTouchBegan:     (UITouch*)touch withEvent: (UIEvent*)event;
-(void) tsTouchMoved:     (UITouch*)touch withEvent: (UIEvent*)event;
-(void) tsTouchEnded:     (UITouch*)touch withEvent: (UIEvent*)event;
-(void) tsTouchCancelled: (UITouch*)touch withEvent: (UIEvent*)event;

@end

and implementation…

@implementation PianoKey

-(id)initWithKey:(int)key {
if((self = [super initWithFile:[NSString stringWithFormat:@"key_%i.png",key]])) {

}
return self;
}


 -(BOOL) tsTouchBegan:(UITouch*)touch withEvent: (UIEvent*)event { 
NSLog( @"tsTouchBegan"); 
return YES; 
}
 -(void) tsTouchMoved:(UITouch*)touch withEvent: (UIEvent*)event { 
NSLog( @"tsTouchMoved"); 

} 
-(void) tsTouchEnded:(UITouch*)touch withEvent: (UIEvent*)event { 
NSLog( @"tsTouchEnded");

}
-(void) tsTouchCancelled:(UITouch*)touch withEvent: (UIEvent*)event { 
NSLog( @"tsTouchCancelled");
}

//
// Utilities. Don't override these unless you really need to.
//

-(CGRect) rect {
CGSize s = [self.texture contentSize];
return CGRectMake(-s.width / 2, -s.height / 2, s.width, s.height);
}

-(BOOL) didTouch: (UITouch*)touch {
return CGRectContainsPoint( [self rect], [self convertTouchToNodeSpaceAR: touch] );
}

//
// The actual touch listener functions. Don't override these either.
//

-(BOOL) ccTouchBegan:(UITouch*)touch withEvent: (UIEvent*)event { 
    NSLog(@"attempting touch.");
    if([self didTouch: touch]) {
        return [self tsTouchBegan:touch withEvent: event]; 
    }
return NO; 
}
-(void) ccTouchMoved:     (UITouch*)touch withEvent: (UIEvent*)event { if([self didTouch: touch])        [self tsTouchMoved:     touch withEvent: event]; }
-(void) ccTouchEnded:     (UITouch*)touch withEvent: (UIEvent*)event { if([self didTouch: touch])        [self tsTouchEnded:     touch withEvent: event]; }
-(void) ccTouchCancelled: (UITouch*)touch withEvent: (UIEvent*)event { if([self didTouch: touch])        [self tsTouchCancelled: touch withEvent: event]; }

@end

I understand the methods above, such as detecting if the the touch was within the bounds of the sprite, however I’m stuck as to why I’m not getting any response when I click the key. I’m new to implementing CCTargetdTouchDelegate so I assume it might be something to do with that…

Answer 1

You don’t need the targeted touch delegate, it just splits the NSSet of touches into individual ccTouchXXX messages. Your implementation is simply lacking the registration and de-registration of the CCTargetedTouchHandler. This is usually done in onEnter, so that it works with any node type and not just CCLayer:

-(void) onEnter
{
    [super onEnter];
    [[TouchDispatcher sharedDispatcher] addTargetedDelegate:self priority:INT_MIN+1 swallowsTouches:YES];
}

-(void) dealloc
{
    [[TouchDispatcher sharedDispatcher] removeDelegate:self];
    [super dealloc];
}

Btw, Kobold2D already has an extended CCNode class that can test if a touch was on a node (sprites, labels, etc) via this test:

[node containsTouch:uiTouch];

Just saying you wouldn’t have had to do all this work. 😉