How to get objects to react to touches in Cocos2D?

Question

Alright, so I'm starting to learn more about Coco2D, but I'm kinda frusterated. A lot of the tutorials I have found are for outdated versions of the code, so when I look through and see how they do certain things, I can't translate it into my own program, because a lot has changed. With that being said, I am working in the latest version of Coco2d, version 0.99.

What I want to do is create a sprite on the screen (Done) and then when I touch that sprite, I can have "something" happen. For now, let's just make an alert go off. Now, I got this code working with the help of a friend. Here is the header file:

// When you import this file, you import all the cocos2d classes
#import "cocos2d.h"

// HelloWorld Layer
@interface HelloWorld : CCLayer
{
 CGRect spRect;
}

// returns a Scene that contains the HelloWorld as the only child
+(id) scene;

@end

And here is the implementation file:

//
// cocos2d Hello World example
// http://www.cocos2d-iphone.org
//

// Import the interfaces
#import "HelloWorldScene.h"
#import "CustomCCNode.h"

// HelloWorld implementation
@implementation HelloWorld

+(id) scene
{
 // 'scene' is an autorelease object.
 CCScene *scene = [CCScene node];

 // 'layer' is an autorelease object.
 HelloWorld *layer = [HelloWorld node];

 // add layer as a child to scene
 [scene addChild: layer];

 // return the scene
 return scene;
}

// on "init" you need to initialize your instance
-(id) init
{
 // always call "super" init
 // Apple recommends to re-assign "self" with the "super" return value
 if( (self=[super init] )) {

  // create and initialize a Label
  CCLabel* label = [CCLabel labelWithString:@"Hello World" fontName:@"Times New Roman" fontSize:64];

  // ask director the the window size
  CGSize size = [[CCDirector sharedDirector] winSize];

  // position the label on the center of the screen
  label.position =  ccp( size.width /2 , size.height/2 );

  // add the label as a child to this Layer
  [self addChild: label];

  CCSprite *sp = [CCSprite spriteWithFile:@"test2.png"];

  sp.position = ccp(300,200);
  [self addChild:sp];
  float w = [sp contentSize].width;
  float h = [sp contentSize].height;
  CGPoint aPoint = CGPointMake([sp position].x - (w/2), [sp position].y - (h/2));
  spRect = CGRectMake(aPoint.x, aPoint.y, w, h);






  CCSprite *sprite2 = [CCSprite spriteWithFile:@"test3.png"];
  sprite2.position = ccp(100,100);
  [self addChild:sprite2];



  //[self registerWithTouchDispatcher];
  self.isTouchEnabled = YES;



 }
 return self;
}


// on "dealloc" you need to release all your retained objects
- (void) dealloc
{
 // in case you have something to dealloc, do it in this method
 // in this particular example nothing needs to be released.
 // cocos2d will automatically release all the children (Label)

 // don't forget to call "super dealloc"
 [super dealloc];
}

- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
  UITouch *touch = [touches anyObject];
  //CGPoint location = [[CCDirector sharedDirector] convertCoordinate:[touch locationInView:touch.view]];
 CGPoint location = [touch locationInView:[touch view]];

 location = [[CCDirector sharedDirector] convertToGL:location];
 if (CGRectContainsPoint(spRect, location)) {
  UIAlertView *alert = [[UIAlertView alloc]
         initWithTitle:@"Win"
         message:@"testing"
         delegate:nil cancelButtonTitle:@"okay"
         otherButtonTitles:nil];

  [alert show];
  [alert release];
  NSLog(@"TOUCHES");
 }
 NSLog(@"Touch got");

}

However, this only works for 1 object, the sprite which I create the CGRect for. I can't do it for 2 sprites, which I was testing. So my question is this: How can I have all sprites on the screen react to the same event when touched?

For my program, the same event needs to be run for all objects of the same type, so that should make it a tad easier. I tried making a subclass of CCNode and over write the method, but that just didn't work at all... so I'm doing something wrong. Help would be appreciated!

Going through the "Touches" project in cocos2D and seeing if I see how they did it. It looks like they made a subclass and overwrote the methods:

- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event
- (void)ccTouchEnded:(UITouch *)touch withEvent:(UIEvent *)event

So now I get to figure out why mine doesn't work... hmm...

Answer 1

I got it. I had to add some more code to the custom class:

Header File:

//
//  CustomCCNode.h
//  Coco2dTest2
//
//  Created by Ethan Mick on 3/11/10.
//  Copyright 2010 Wayfarer. All rights reserved.
//

#import "cocos2d.h"


@interface CustomCCNode : CCSprite <CCTargetedTouchDelegate> {

}

@property (nonatomic, readonly) CGRect rect;


@end

Implementation:

//
//  CustomCCNode.m
//  Coco2dTest2
//
//  Created by Ethan Mick on 3/11/10.
//  Copyright 2010 Wayfarer. All rights reserved.
//

#import "CustomCCNode.h"
#import "cocos2d.h"


@implementation CustomCCNode

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



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

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


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





- (BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event
{
    NSLog(@"ccTouchBegan Called");
    if ( ![self containsTouchLocation:touch] ) return NO;
    NSLog(@"ccTouchBegan returns YES");
    return YES;
}

- (void)ccTouchMoved:(UITouch *)touch withEvent:(UIEvent *)event
{
    CGPoint touchPoint = [touch locationInView:[touch view]];
    touchPoint = [[CCDirector sharedDirector] convertToGL:touchPoint];

    NSLog(@"ccTouch Moved is called");
}

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


@end

Answer 2

Hi,

I'm a begginer at this, but this file saved me a lot of trouble, I now understand a lot more stuff, and the way to properly instantiate this is: (at least how I did it was)

+(id)scene{
    CustomCCNode *myNode = [CustomCCNode spriteWithFile:@"myPng.png"];
    myNode.position = ccp(150,150);
    [scene addChild:myNode];
    return scene;
}

Open the console and look at the messages send when touch events are triggered.

Thanks!

Answer 3

how about sprites in move. If sprite with runAction this doesnt work