How to passing class argument to selector in objective C? - iphone

Question

I want to set the class tile value by click on the button
if click onPlus it will have a string value = #"+"
if click onMinus it will have a string value = #"-"
here are the code
//Class Tile
#interface Tile : TouchableNode {
NSString *val;
}
-(void) setVal:(NSString *)v
{
val = v;
}
-(NSString *) getVal
{
return val;
}
And the in another class
I have a code like this
for(Tile *tile in player)
{
if (tile.getVal == #"P") {
if (pauseStatus == 0) {
pauseStatus = 1;
[[CCDirector sharedDirector] pause];
CGSize size = [[CCDirector sharedDirector] winSize];
pauseLayer=[[CCLayer alloc] init];
pauseLayer.anchorPoint=ccp(0,0);
pauseLayer = [CCLayerColor layerWithColor: ccc4(0, 0, 255, 125) width: 300 height: 150];
pauseLayer.position = ccp(size.width/2, size.height/2);
pauseLayer.isRelativeAnchorPoint = YES;
[self addChild: pauseLayer z:8];
//Here are 2 two button that when user click it will have #"+" value or #"-"
plusBtn = [CCMenuItemImage itemFromNormalImage:#"plus.png" selectedImage:#"plus.png" target:self selector:#selector(onPlus:)];
minusBTn = [CCMenuItemImage itemFromNormalImage:#"minus.png" selectedImage:#"minus.png" target:self selector:#selector(onMinus:)];
pauseMenu = [CCMenu menuWithItems:plusBtn, minusBTn, nil];
[pauseMenu alignItemsHorizontally];
[self addChild:pauseMenu z:10];
}
}
}
and I have onPlus & onMinus method that I want to send object tile to that method
-(void)onPlus:(Tile *) set
{
NSString *plus = #"+";
[set setVal:plus];
}
-(void)onMinus:(Tile *) set
{
NSString *minus = #"-";
[set setVal:minus];
}
How to pass the object tile to the method??
Or it have another way to make it??

Answer 1

CCMenuItemImage inherits from CCNode, which has a void* userData property. If you assign tile to userData, you could fetch it back from the (id)sender in your onPlus/onMinus methods.
plusBtn = [CCMenuItemImage itemFromNormalImage:#"plus.png" selectedImage:#"plus.png" target:self selector:#selector(onPlus:)];
plusBtn.userData = (void*)tile; // You may need a bridge cast in ARC
minusBTn = [CCMenuItemImage itemFromNormalImage:#"minus.png" selectedImage:#"minus.png" target:self selector:#selector(onMinus:)];
minusBTn.userData = (void*)tile;
-(void)onPlus:(id)senderObj {
CCNode *sender = (CCNode*)senderObj;
Tile *myTile = (Tile*)sender.userData; // Again you may need a bridge cast here
}

Answer 2

If you want to send a Tile object to your onPlus handler, just subclass CCMenuItemImage and make a Tile property:
#interface MyCustomCCMenuItemImage : CustomCCMenuItemImage
#property (nonatomic, retain) Tile* tile;
#end
Here's a rough example of what your code might look like:
- (void)someMethod
{
for(Tile *tile in player)
{
plusBtn = [MyCustomCCMenuItemImage itemFromNormalImage:#"plus.png" selectedImage:#"plus.png" target:self selector:#selector(onPlus:)];
plusBtn.tile = tile ;
}
}
//Your handler
-(void)onPlus:(id)sender
{
Tile *myTile = sender.tile;
}

Answer 3

For string comparisons, you're better off using
[tile.getVal isEqualToString:#"P"]
Since the method you use only works if it's the exact same string (in the same memory location), as opposed to an equivalent string elsewhere .