Question

I am attempting to make a basic game which requires a serious of buttons to control player movement. Keep in mind I am using cocos-2d. My goal is to have the buttons be holdable and move a sprite when held down. The code i am using now looks like this.

CCMenuItemHoldable.h

@interface CCMenuItemSpriteHoldable : CCMenuItemSprite {
    bool buttonHeld;
}

@property (readonly, nonatomic) bool buttonHeld;

CCMenuItemHoldable.m

@implementation CCMenuItemSpriteHoldable

@synthesize buttonHeld;

-(void) selected
{
    [super selected];
    buttonHeld = true;
    [self setOpacity:128];
}

-(void) unselected
{
    [super unselected];
    buttonHeld = false;
    [self setOpacity:64];
}

@end

and for the set up of the buttons

rightBtn = [CCMenuItemSpriteHoldable itemFromNormalSprite:[CCSprite spriteWithFile:@"art/hud/right.png"] selectedSprite:[CCSprite spriteWithFile:@"art/hud/right.png"] target:self selector:@selector(rightButtonPressed)];


CCMenu *directionalMenu = [CCMenu menuWithItems:leftBtn, rightBtn, nil];
[directionalMenu alignItemsHorizontallyWithPadding:0];
[directionalMenu setPosition:ccp(110,48)];
[self addChild:directionalMenu];

This all seems to work fine but when i do

-(void)rightButtonPressed:(id) sender
{

    if([sender buttonHeld])
            targetX = 10; 
        else{
            targetX = 0; 
        }   
}

The crash has been fixed but I am trying to get my sprite to move. In my game tick function I add the value of targetX to the position of the sprite on a timer, still no movement.

Answer 1

Please, always include a crash log when asking questions about crashes.

In your case, I can guess the problem. You are adding this selector:

@selector(rightButtonPressed)

Your method is called

rightButtonPressed:(id)sender

Which would be, as a selector, rightButtonPressed: – note the colon indicating that an argument is passed. Either change the method so it has no argument, or add a colon to the selector when you create the button.

The crash log would be telling you this – it would say “unrecognised selector sent to…” with the name of the receiving class, and the name of the selector.