Question

I have a recursive function that plays a UIView animation continuously (if there is a better way to do this, please let me know):

-(void)playAnimationRecursive
{
    [appDelegate commenceFishAnimation];
    [animationView addSubview:appDelegate.fishAnimationImageView];
    animationView.alpha=0.5;

    [NSTimer scheduledTimerWithTimeInterval:14.0 target:self selector:@selector(playAnimationRecursive) userInfo:nil repeats:NO];
}

and not sure if this is neccessary, but here’s the appDelegate commenceFishAnimationMethod:

        upperFish=[[UIImageView alloc] initWithImage:upperFishImage];
        bigFish=[[UIImageView alloc] initWithImage:bigFishImage];
        shark=[[UIImageView alloc] initWithImage:sharkImage];
        groupFish=[[UIImageView alloc] initWithImage:groupFishImage];
        fish1=[[UIImageView alloc] initWithImage:fish1Image];
        fishAnimationImageView=[[[UIImageView alloc] init] retain];

        //set the initial position of each fish to be out of frame
        upperFish.frame=CGRectMake(-50, 150, 119/2, 93/2); //moves east
        bigFish.frame=CGRectMake(-280, 340, 251/2, 137/2); //moves east
        shark.frame=CGRectMake(-100, 390, 164/2, 52/2); //moves east
        groupFish.frame=CGRectMake(500, 320, 155/2, 89/2); //moves west
        fish1.frame=CGRectMake(370, 280, 155/2, 89/2); //moves west

        //add fishes to current view
        [fishAnimationImageView addSubview:upperFish];
        [fishAnimationImageView addSubview:bigFish];
        [fishAnimationImageView addSubview:shark];
        [fishAnimationImageView addSubview:groupFish];
        [fishAnimationImageView addSubview:fish1];

        //animate the position of each fish view
        [UIView beginAnimations:nil context:NULL];
        [UIView setAnimationDuration:10.0];
        [UIView setAnimationCurve:UIViewAnimationCurveLinear];
        upperFish.transform=CGAffineTransformMakeTranslation(150, -200);
        bigFish.transform=CGAffineTransformMakeTranslation(600, 0);
        shark.transform=CGAffineTransformMakeTranslation(550, 0);
        groupFish.transform=CGAffineTransformMakeTranslation(-600, 0);
        fish1.transform=CGAffineTransformMakeTranslation(-550, 0);

        [UIView commitAnimations];
        [fishAnimationImageView release];
        [upperFish release];
        [bigFish release];
        [shark release];
        [groupFish release];
        [fish1 release];  
}

So what happens is that every view I have plays this animation in the BG, so if I’m on view A, then it calls the recursive function and plays the animation continuously. If I move to view B, then it calls the recursive function also and plays the animation continuously. However, I’m getting memory warning level 2, and I’m thinking maybe it’s because view A is still calling the recursive method? If that is the reason, then how would I stop the recursive method on unload? Or is that not my problem?

EDIT:

Here’s my code now (animation doesn’t loop)

-(void)commenceFishAnimation
{
    UIImageView *newImageView=[[UIImageView alloc] init];
    self.fishAnimationImageView=newImageView;

    upperFish=[[UIImageView alloc] initWithImage:upperFishImage];
    bigFish=[[UIImageView alloc] initWithImage:bigFishImage];
    shark=[[UIImageView alloc] initWithImage:sharkImage];
    groupFish=[[UIImageView alloc] initWithImage:groupFishImage];
    fish1=[[UIImageView alloc] initWithImage:fish1Image];

    //set the initial position of each fish to be out of frame
    upperFish.frame=CGRectMake(-50, 150, 119/2, 93/2); //moves east
    bigFish.frame=CGRectMake(-280, 340, 251/2, 137/2); //moves east
    shark.frame=CGRectMake(-100, 390, 164/2, 52/2); //moves east
    groupFish.frame=CGRectMake(500, 320, 155/2, 89/2); //moves west
    fish1.frame=CGRectMake(370, 280, 155/2, 89/2); //moves west

    //add fishes to current view
    [fishAnimationImageView addSubview:upperFish];
    [fishAnimationImageView addSubview:bigFish];
    [fishAnimationImageView addSubview:shark];
    [fishAnimationImageView addSubview:groupFish];
    [fishAnimationImageView addSubview:fish1];

    //animate the position of each fish view
    [UIView beginAnimations:nil context:NULL];
    [UIView setAnimationDuration:10.0];
    [UIView setAnimationCurve:UIViewAnimationCurveLinear];
    upperFish.transform=CGAffineTransformMakeTranslation(150, -200);
    bigFish.transform=CGAffineTransformMakeTranslation(600, 0);
    shark.transform=CGAffineTransformMakeTranslation(550, 0);
    groupFish.transform=CGAffineTransformMakeTranslation(-600, 0);
    fish1.transform=CGAffineTransformMakeTranslation(-550, 0);

    [UIView setAnimationDelegate:self];
    [UIView setAnimationDidStopSelector:@selector(commenceFishAnimation)];
    [UIView commitAnimations]; 

    [fishAnimationImageView release];
    [upperFish release];
    [bigFish release];
    [shark release];
    [groupFish release];
    [fish1 release];
    //[newImageView release]; //if I release it, then my animation doesn't play for some reason
}

Then in some other class in the viewDidLoad method, I do this:

[appDelegate commenceFishAnimation];
[animationView addSubview:appDelegate.fishAnimationImageView];

But the animation only plays once.

Answer 1

That’s not the best way chaining animations, use this instead:

    [UIView setAnimationDidStopSelector:@selector(playAnimation)];

That will chain your animations in an infinite loop.

But also note that in your method playAnimationRecursive you are adding subviews and scheduling a NSTimer every 14 seconds without releasing them. Thats a really bad idea.

To sum up: forget about recursion and use the method above.

EDIT: I forgot to mention that you have to assign the delegate of the animation:

[UIView setAnimationDelegate:self];  //self or whatever implements playAnimation selector