Setting delegate to the parent of pushed scene - cocos2d-iphone

In my HelloWorldLayer code I am pushing a SettingsLayer scene onto the stack.
[[CCDirector sharedDirector] pushScene:[CCTransitionFade transitionWithDuration:0.5 scene:[SettingsLayer scene]]];
The SettingsLayer needs to call a delegate method implemented in the HelloWorldLayer. But I am at a lost as to how I can set the HelloWorldLayer as the SettingsLayer's delegate. Can someone show me the proper pattern for this? I tried alloc-init of the SettingsLayer, and setting the delegate before the pushscene but this did not work.

In your code:
SettingsLayer *mySettingsLayer = [[SettingsLayer alloc] init];
mySettingsLayer.delegate = self;
[[CCDirector sharedDirector] pushScene:[CCTransitionFade transitionWithDuration:0.5
scene:[[mySettingsLayer class] scene]]];
The problem is in the last line:
[[mySettingsLayer class] scene]
This creates a new instance of the SettingsLayer class which has no delegate set (it will be nil). The mySettingsLayer you created before isn't actually presented as a scene, it goes out of scope and deallocates (assuming you are using ARC, if not, this would actually leak the mySettingsLayer object).
To fix it pass in your already existing mySettingsLayer instance:
[[CCDirector sharedDirector] pushScene:[CCTransitionFade transitionWithDuration:0.5
scene:mySettingsLayer]];

Related

Making any given instance of a CCNode reactive to touch

So in my project I am using Cocos2D with CocosBuilder. I have assigned a few of my characters to be subclasses of CCNode with child CCSprites, etc.
I want these CCNodes to be reactive to touch - for example, if I touch any of them, they'd play a context sensitive animation. I only want to know how to make the node reactive to touch (or perhaps, having the layer reactive to touch which detects whether you've touched a sprite or not), the animation part is fine.
Any ideas? that would be lovely.
Sam
Turns out that this is fairly easy. In the header file of your class, you must define the class as implementing the protocol , like so:
#interface Foo : CCNode <CCTouchOneByOneDelegate>
{
}
and you must implement onEnter and onExit like this:
- (void)onEnter
{
[[[CCDirector sharedDirector] touchDispatcher] addTargetedDelegate:self priority:0 swallowsTouches:YES];
[super onEnter];
}
- (void)onExit
{
[[[CCDirector sharedDirector] touchDispatcher] removeDelegate:self];
[super onExit];
}
and you must implement ccTouchBegan (if you're using the OneByOneDispatcher)

Cocos2d - Allow touches to be used by multiple classes (sneakyjoystick)

Evening all,
I'll start this question in the time honoured tradition by saying that I've had a good old search on SO and also in the wider world but I'm not quite getting my head around this...
I've implemented a sneakyJoystick which works wonderfully (It moves my sprite around quite happily) however I've now done myself a mischief in thinking about it's positioning.
What I'd like to do is simply change it's position to a touch location and have it move my sprite around but this seems to be out of my knowledge pool. I might be being an idiot but I cannot work it out.
The touch events are already sorted in the sneakyjoystick classes (available on github https://github.com/0xPr0xy/sneaky-joystick-cocos2d). At the moment if I create the joystick during the init method in a class called controlsLayer then everything works fine; Joystick appears and it allows me to move to sprite around
-(id) init
{
if( (self=[super init]) ) {
myJoystickBase = [[[SneakyJoystickSkinnedBase alloc] init] autorelease];
myJoystickBase.backgroundSprite = [CCSprite spriteWithFile:#"dpad.png"];
myJoystickBase.thumbSprite = [CCSprite spriteWithFile:#"joystick.png"];
myJoystickBase.joystick = [[SneakyJoystick alloc] initWithRect:CGRectMake(0, 0, 128, 128)];
myJoystickBase.position = ccp(64, 64);
myJoystickBase.backgroundSprite.opacity = 100;
myJoystickBase.thumbSprite.opacity = 100;
[self addChild:myJoystickBase];
myJoystick = [myJoystickBase.joystick retain];
[self scheduleUpdate];
}
return self;
}
So to begin with I thought about looking at how I could simply get it to show and hide itself and set it's location. To do this I created a ccTouchesbegan method which contains pretty much the same code as my init method did before. This works fine up to a point (the joystick appears centred wherever I touch) but the issue now is that I cannot interact with it. The joystick appears where i want but it will not recognise my movements (the stick on the joystick does not move which in turn means that my sprite is not being told to move either)
if( (self=[super init]) ) {
self.isTouchEnabled = YES;
[self scheduleUpdate];
}
return self;
}
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
CGPoint location = [[CCDirector sharedDirector] convertToGL:[touch locationInView:[touch view]]];
location = [self convertToNodeSpace:location];
myJoystickBase = [[[SneakyJoystickSkinnedBase alloc] init] autorelease];
myJoystickBase.backgroundSprite = [CCSprite spriteWithFile:#"dpad.png"];
myJoystickBase.thumbSprite = [CCSprite spriteWithFile:#"joystick.png"];
myJoystickBase.joystick = [[SneakyJoystick alloc] initWithRect:CGRectMake(0, 0, 128, 128)];
myJoystickBase.position = location;
myJoystickBase.backgroundSprite.opacity = 100;
myJoystickBase.thumbSprite.opacity = 100;
[self addChild:myJoystickBase];
myJoystick = [myJoystickBase.joystick retain];
}
-(void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
[self removeChild:myJoystickBase cleanup:YES];
}
So to my uninitiated brain this is saying that when I touch the controlsLayer class it happily does what I've asked it to but it will not then pass this touch to other classes.
In a nutshell can a touch event be passed to multiple classes at the same time? The sneaky joystick class uses CCTargetedTouchDelegate which worked fine when it was the only thing looking for a touch. However now that I've added a -(void)ccTouchesBegan: in another class it's not happy.
Can anyone tell me if the problem is with the way I'm handling touches or is it possibly an issue with the way that I allocate the joystick in the touch method? Should I be allocating the joystick in the init method and be doing something else in the touchesBegan method? Trial and error isn't getting me anywhere useful at the moment. Feel like I'm banging my head against a brick wall. I'm happy to post up the full class files if necessary. Does this make sense?
The problem is that you create the joystick during touch began, and remove it on touch ended. This does not allow the joystick to receive a touch began event, since the event is already being processed at the time the joystick is being created.
You're also leaking the joystick due to the unnecessary retain (use ARC, please!).
Try creating the joystick in init, disable & hide it until a touch began event is received. This is also faster than recreating the joystick on every touch.
Also, should you have multiple touches enabled, keep in mind that you can receive up to 5 touch began events (5 fingers) without any touch ended in between. That would create 5 joysticks, but only remove one! Every time!

what causes a scene's schedule to run even after the scene is replaced?

i have a scene1 that is replaced by scene2
[[ccdirector shareddirector]replacescene:scene2]//scene2 replacement
after doing some selection on scene2 i am again replacing the scene
again with scene1
[[ccdirector shareddirector]replacescene:scene1] //scene1 replacement
but scene2's schedule is still running, and i havent really retained
anything in scene2, pls help me with this!!
This can only happen if your scene isn't released. That means, yes, you do retain it somehow. Keep in mind that adding an object to an NSArray or NSDictionary retains it.
Set a breakpoint in each scene's -(void) dealloc method, or add an NSLog/CCLOG line, to make sure the scene is properly deallocated.
I'm guessing from your code that you're actually holding on to the scene1 and scene2 objects. You should not do that. Instead, create a new instance of the scene class every time you change it, like so:
[[CCDirector sharedDirector] replacescene:[Scene2 node]];

Accessing Objects in other Layers (cocos2d)

I was playing around with a Joystick moving a Sprite around in one layer. Now, according to best practice, the Joystick and the Sprite have to be in different Layers of the same scene. I have managed to separate these, yet I am now completely stuck having absolutely no clue whatsoever how to pass joystick commands from one layer to another? What is the recommended way to do this?
Scene
Game Play Layer
Sprite
Game Control Layer
Joystick
When the joystick is manipulated I need to pass this info to the GamePlayLayer to control the sprite.
Well, I got a great Cocos2d book, written by Rod Strougo and Ray Wenderlich, by the name "Learning Cocos2d". In their book, they implement a game, which has a joystick implemented and all, using your initial setup. The GamePlayLayer contains both the joyStick and the hero sprite. (See book page 40).
I don't believe they would use bad practices in their book, given they are very talented!
...
With that being said, I have possible solutions, if you wish to implement them on separate layers:
GameScene
|
|__>GameLayer
|
|__>ControlLayer
That's your basic setup. But, intuitively, what is the purpose of the control layer? Control the game layer's content! So, I would suggest you hold a (weak) reference to the GameLayer within the ControlLayer. That way, using a simple:
#property (nonatomic, assign) CCSprite* hero;
you now have access to the hero from the ControlLayer!
Extra (if needed):
//GameScene init:
- (id)init {
....
gameLayer = [GameLayer node];
controlLayer = [ControlLayer node];
[controlLayer setGameLayerRef:gameLayer];
...
}
// Control layer:
#property (nonatomic, assign) GameLayer* gameLayerRef;
Even though I just suggested that way, I don't use it in my games :)
What I normally do is:
Make the GameScene class a "Semi-Singleton". (I learned this method from "Learn iPhone and iPad Game Dev" By Itterheim (aka gaming horror, Kobold2d publisher ... etc).
Then, inside the control layer, I would call the GameScene object:
[[GameScene sharedScene] doSomethingToTheGameLayer];
Yeah, the gameScene has simplistic methods that just relies what the control need to update in the game layer.
Edit:
Implementing the Semi-singleton pattern, as described by Itterheim in his book.
But, what is semi-singleton?
It has the singleton pattern's property: you can access the object instance from anywhere using a static call.
[GameScene sharedScene];
However, singleton objects are usually retained, after being created for the first time, till the end of the application's life. In the Semi-singleton pattern, this is not the case.
Once you create the instance, you cannot create another instance before destroying the old one, BUT once you are done with the instance, you destroy it (dealloc). Creating another one when necessary.
Recap:
Semi-Singleton: Create many object from it, but only one at any given time. Only recreate after destroying the old.
Implementation:
Of course, as you do with any singleton class, you first declare a static variable of the same type of the class:
//In GameScene.m
static GameScene* instance = nil;
#implementation
//Here we have the static method to access the instance:
+(GameScene*)sharedScene {
//you must have created one before trying to access it "Globally".
///Typically, created where you transition the GameScene using CCDirector's replaceScene.
NSAssert(instance != nil, #"GameScene not instantiated!!");
return instance;
}
-(id)init {
if((self = [super init])) {
//Make sure you don't have another instance of the class created
//NOTE: Possible race condition that I wouldn't worry about, since it should never happen.
NSAssert(instance == nil, #"Another instance is already created!!");
instance = self;
...
}
return self;
}
//Don't forget!! Dealloc!!
- (void)dealloc {
//the only instance we had is dealloc'd! We are back to zero. Can create a new one later! :D
instance = nil;
[super dealloc];
}
Edit2:
So, the timeline:
CCScene* scene = [GameScene node];
[[CCDirector sharedDirector] replaceScene:scene];
...
[[GameScene sharedScene] doSomething];
...
[[CCDirector sharedDirector] replaceScene:otherScene];
//After the new scene replaces GameScene, dealloc will be called, implicitly. Making instance = nil;
instance = nil;
[super dealloc];
...
//Loop again
CCScene* scene = [GameScene node];
[[CCDirector sharedDirector] replaceScene:scene];
...

How to restart a level in an iPhone game

I want to restart the current scene i am on. I thought of using replaceScene and replace it with itself. Is that ok to do ?
Level2Scene *scene = [Level2Scene node];
[[CCDirector sharedDirector] replaceScene:scene];
Level2Scene is the current scene I am in.
Thanks
Abhinav
Using replaceScene: is a good way to restart the level, if levels are represented by scenes. Just make sure that if you have any global state (stored outside of the scene) that you reset that, too.