Question

i have two layers control layer which contains CCLabelTTF for score, and first layer in which i detect collision btwn my objects. i want to update score (i.e CCLabelTTF value) in control layer from my first layer.

here is my code…

my scene.m

-(id)init{

    self=[super init];   

    FirstLayer *fl=[FirstLayer node];

    [self addChild:fl];

    controlLayer *cl=[controlLayer node];

    [self addChild:cl z:3 tag:1];

    return self;


       }

control layer.h

@interface controlLayer : CCLayer{
     CCLabelTTF * score ;
     int score_value;        
}

@property(nonatomic,retain)CCLabelTTF * score ;
@property int score_value;

-(void)displayScore;    
@end

controlLayer.m

-(id)init{        
   // my code..            
        [self displayScore];            
    }

    return self;
}


-(void)displayScore{        
    CGSize screenSize=[[CCDirector sharedDirector]winSize];    
    CCLabelTTF * score_lbl = [CCLabelTTF labelWithString:@"Score" fontName:@"Arial" fontSize:16.0];    
    score_lbl.position=ccp(screenSize.width*0.10,screenSize.height*0.90);        
    [self addChild:score_lbl z:99];

    score =[CCLabelTTF labelWithString:[NSString stringWithFormat:@"test:%d",score_value] fontName:@"Arial" fontSize:16.0] ;          
    NSString *str = [score string];        
    NSLog(@"SCORE control:%@",str);    
    score.position=ccp(screenSize.width*0.20,screenSize.height*0.90);        
    [self addChild:score];        
}

firstLayer.h

@interface FirstLayer : CCLayer     
{           
    controlLayer *cl;                
    }

@property(nonatomic,retain)controlLayer *cl;    

@end

firstLayer.m

@implementation FirstLayer

@synthesize cl;    
    -(id)init{

 ---

cl=[controlLayer new];
[self schedule:@selector(tick:)];

    return self;

}


-(void)tick:(ccTime)dt{           
    bool blockFound=false;        
    world->Step(dt, 10, 10);      

    std::vector<MyContact>::iterator pos;
    for(pos = _contactListener->_contacts.begin(); 
        pos != _contactListener->_contacts.end(); ++pos) {
        MyContact contact = *pos;          

        b2Body *bodyA = contact.fixtureA->GetBody();
        b2Body *bodyB = contact.fixtureB->GetBody();
        if (bodyA->GetUserData() != NULL && bodyB->GetUserData() != NULL) {
            CCSprite *spriteA = (CCSprite *) bodyA->GetUserData();
            CCSprite *spriteB = (CCSprite *) bodyB->GetUserData();                         

            // Sprite A = ball, Sprite B = Block
            if (spriteA.tag == 1 && spriteB.tag == 2) {                    

                cl.score_value=cl.score_value+5;

                [cl.score setString:[NSString stringWithFormat:@"%d",cl.score_value]];                                   

                NSString *str = [cl.score string];

                NSLog(@"SCORE in GAME:%@",str);

               // [cl displayScore];                        

                if (std::find(toDestroy.begin(), toDestroy.end(), bodyB) 
                    == toDestroy.end()) {
                    toDestroy.push_back(bodyB);

                }
            }
            // Sprite B = block, Sprite A = ball
            else if (spriteA.tag == 2 && spriteB.tag == 1) {                      

                cl.score_value=cl.score_value+5;

               [cl.score setString:[NSString stringWithFormat:@"%d",cl.score_value]];

                NSString *str = [cl.score string];

                NSLog(@"SCORE in GAME:%@",str);

             //    [cl displayScore];                    

            }               

        }                 
    }

What is going Wrong? , i’m always getting score:test 0 !:(

Answer 1

Your statement cl=[controlLayer new]; is not getting the reference of the controlLayer that was added to your game scene. As your game scene.m code indicates, both FirstLayer and controlLayer instances are initalized and added as children to the CCScene. To get a proper reference to your controlLayer from inside FirstLayer, do it like this:

FirstLayer.m

-(void) onEnter {
[super onEnter];
cl = (controlLayer*)[self.parent getChildByTag:1];
}

The reason you have to put this in onEnter is because self.parent will not be valid within the FirstLayer’s init method. onEnter is called after initialization is complete. This should give you the reference to the actual controlLayer that was added to your game scene.