Question

I’d like to schedule a selector in a child node of the class GameScene without having to call the schedule method in the child node class (e.g. [self schedule etc..]).

Here is the code snippet I am calling in the GameScene class to call a method in the child class that handles the background of my GameScene.

ParallaxMultipleBackgrounds *background = [self getChildByTag:GameSceneBackgroundBase];
//I TRIED THIS:
[background schedule:@selector(([background changeSpeedFactorBy:3])) interval:1];
//AND 
[background schedule:@selector(changeSpeedFactorBy:3)];
//AND
[[background schedule:@selector(changeSpeedFactorBy:3) interval:1] ];
//BUT..

Unfortunately none of those methods call works as I get various error message from the compiler. I am not sure how what I am doing wrong because I declared the selector -(void) changeSpeedFactorBy:(float)factor in the ParallaxMultipleBackgrounds class.

Any help?

Answer 1

You cannot give an argument to the selector.
The easiest way to do that is to have an iVar in the ParallaxMultipleBackgrounds class like this: int modifier. Make it a readwrite property.
Then assign it and call the schedule method.

Like this :

ParallaxMultipleBackgrounds *background = [self getChildByTag:GameSceneBackgroundBase];
background.modifier = 3;
[background schedule:@selector(changeSpeedFactorBy:) interval:1];

And in the changeSpeedFactorBy method make the change by using that modifier variable.

Hope this helps.

Cheers!

EDIT: You can also send a parameter by sing CCCallFuncND. And if you then declare a CCRepeatForever action you can indeed call a selector forever with a param.
Like this:

CCCallFuncND *call = [CCCallFuncND actionWithTarget:background selector:@selector(changeSpeedFactorBy:) data:amont];

CCDelay *delay = [CCDelay actionWithDuration:1];

CCSequence *seq = [CCSequence actions:call,delay,nil];

CCRepeatForever *repeat = [CCRepeatForever actionWithAction:seq];
[background runAction:repeat];

Sorry for any syntax errors , I’m not on a Mac right now. But that would be a whole idea. One mention though , when you sent that data argument , it’s a void* . So you won’t be able to send an integer there , but you can with a NSString.