Question

It might be that I am missing something fundamental. I have made a class that inherits CCSprite, called Dude. In my layer I add the object dude, which works correctly: it shows on the screen. Everything goes well, until I touch the screen. Somehow the method “Jump” in my class Dude can’t be reached.

The error I get is:

-[CCSprite Jump::]: unrecognized selector sent to instance 0xf4611a0
2012-05-18 10:20:40.870 bitman[1732:10a03] * Terminating app due to uncaught exception ‘NSInvalidArgumentException’, reason: ‘-[CCSprite Jump::]: unrecognized selector sent to instance 0xf4611a0’

Can anyone point me in the right direction? Why does the error say [CCSprite Jump::] instead of [Dude Jump::]? What is it that I am missing?

I have a Layer setup as followed (only relevant code):

#import "GameplayLayer.h"
#import "Dude.h"

@implementation GameplayLayer

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

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

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

    // return the scene
    return scene;
}

-(id)init{
    self=[super init];
    if(self!=nil){
        dude=[[Dude alloc]init] ;
        dude.position=ccp(screenSize.width/2,screenSize.height/2);
        [self addChild:dude];

        fJumpHight=screenSize.height/3;
        fJumpTime=.2f;
    }
    return self;
}

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

-(BOOL)ccTouchBegan:(UITouch *)touch withEvent:(UIEvent *)event{
    [dude Jump:40:3];
    return YES;
}

@end

I setup the class Dude as followed:
Dude.h:

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

@interface Dude : CCSprite

    -(void) Jump:(float)fHight:(float)fTime;

@end

Dude.m:

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

@implementation Dude
-(id)init{
    self=[super init];
    if(self!=nil){

        CGSize screenSize =[CCDirector sharedDirector].winSize;
        self=[[CCSprite spriteWithFile:@"something.png"]retain];
        self.position=ccp(screenSize.width/2,screenSize.height*0.333f);

    }
    return self;
}

-(void) Jump:(float)fHight:(float)fTime{
    NSLog(@"JUMP!");
    //Jump actions    
}
@end

Answer 1

Your main error is within the implementation of your Dude.

self=[[CCSprite spriteWithFile:@"something.png"]retain];

First, you correctly assign self = [super init] wich leaves self as a Dude but by overwriting self with [CCSprite spriteWithFile:...] you change that to a default CCSprite.

You could instead use self = [super initWithFile:@"something.png"]. Like this:

-(id)init {
  self = [super initWithFile:@"something.png"];
  if (self == nil) return nil;

  CGSize screenSize =[CCDirector sharedDirector].winSize;
  self.position = ccp(screenSize.width / 2.0, screenSize.height / 3.0);

  return self;
}

Another piece of advice: In objc methods are usually lowercase and tend to give you more information about the parameters.
So you might consider renaming your Jump:: to

-(void)jumpWithHeight:(float)height duration:(ccTime)duration {
  ...
}

This is due to the fact that you read code more often than you write it 😉