SpriteKit Pause and Resume SKView

Question

I want to Pause and Unpause a Scene in SpriteKit, with 2 Buttons on the same position. While the Scene is running, I want to show the 'Pause' Button. While the Scene is paused, I want to hide the 'Pause' Button and show the 'Play' Button. In SpriteKit you can use self.scene.view.paused which is defined in SpriteKit.

My Code:

@implementation MyScene {

SKSpriteNode *PauseButton;
SKSpriteNode *PlayButton;

}

-(id)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {

[self Pause];

}
return self;
}

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
/* Called when a touch begins */

UITouch * touch = [touches anyObject];
CGPoint location = [touch locationInNode:self];

SKNode * Node = [self nodeAtPoint:location];

if([Node.name isEqualToString:@"PauseButton"]){

    self.scene.view.paused = YES;

    [PauseButton removeFromParent];
    [self Resume];
}

if([Node.name isEqualToString:@"PlayButton"]){

    self.scene.view.paused = NO;

    [PlayButton removeFromParent];
    [self Pause];
}
}

-(void)Pause{

PauseButton = [SKSpriteNode spriteNodeWithImageNamed:@"Pause.png"];
PauseButton.position = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 1.04);
PauseButton.zPosition = 3;
PauseButton.size = CGSizeMake(40, 40);
PauseButton.name = @"PauseButton";

[self addChild:PauseButton];

}

-(void)Resume{

PlayButton = [SKSpriteNode spriteNodeWithImageNamed:@"Play.png"];
PlayButton.position = CGPointMake(self.frame.size.width / 2, self.frame.size.height / 1.04);
PlayButton.zPosition = 3;
PlayButton.size = CGSizeMake(60, 60);
PlayButton.name = @"PlayButton";
[self addChild:PlayButton];

}

It pauses the Scene, but the there is still the Pause Button, and if I touch the Pause Button again, the Scene resumes. So now only the Images won't change. How can I fix this?

Answer 1

You can't update the button (or anything else in the scene) while the SKView is paused. In your touchesBegan method, you are pausing the view before updating the button (changing the order won't work). You will need to return to the run loop so your button is updated before pausing the game. Here's one way to do that:

This calls a method to pause the view after a short delay. Add this after your [self Resume] statement in touchesBegan, and delete self.scene.view.paused = YES.

    [self performSelector:@selector(pauseGame) withObject:nil afterDelay:1/60.0];

This method pauses the SKView. Add this to your MyScene.m

- (void) pauseGame
{
    self.scene.view.paused = YES;
}