How do I simultaneously animate a UIImageView's image and the UIImageView itself?

Question

The title may not be so clear, but what I want to do is to make the UIImageView display a series of images (sort of like a gif) and I do this by setting the animationI

Answer 1

This is not a good way to make a sprite. I could insist that you should be using OpenGL, but there may be no need to go that far; you can do it all with Core Animation of a layer, and I think you'll be better off doing that than trying to use a full-fledged UIImageView.

Using Core Animation of a layer, I was able to make this PacMan sprite animate across the screen while opening and closing his mouth; isn't that the sort of thing you had in mind?

Here is a video showing the animation!

http://www.youtube.com/watch?v=WXCLc9ww8MI

And yet the actual code creating the animation is extremely simple: just two layer animations (Core Animation), one for the changing image, the other for the position.

You should not award this answer the bounty! I am now merely echoing what Seamus Campbell said; I'm just filling out the details of his answer a little.

Okay, so here's the code that generates the movie linked above:

- (void)viewDidLoad {
    [super viewDidLoad];
    // construct arr, an array of CGImage (omitted)
    // it happens I've got 5 images, the last being the same as the first
    self.images = [arr copy];
    // place sprite into the interface
    self.sprite = [CALayer new];
    self.sprite.frame = CGRectMake(30,30,24,24);
    self.sprite.contentsScale = [UIScreen mainScreen].scale;
    [self.view.layer addSublayer:self.sprite];
    self.sprite.contents = self.images[0];
}

- (void)animate {
    CAKeyframeAnimation* anim = 
        [CAKeyframeAnimation animationWithKeyPath:@"contents"];
    anim.values = self.images;
    anim.keyTimes = @[@0,@0.25,@0.5,@0.75,@1];
    anim.calculationMode = kCAAnimationDiscrete;
    anim.duration = 1.5;
    anim.repeatCount = HUGE_VALF;

    CABasicAnimation* anim2 = 
        [CABasicAnimation animationWithKeyPath:@"position"];
    anim2.duration = 10;
    anim2.toValue = [NSValue valueWithCGPoint: CGPointMake(350,30)];

    CAAnimationGroup* group = [CAAnimationGroup animation];
    group.animations = @[anim, anim2];
    group.duration = 10;

    [self.sprite addAnimation:group forKey:nil];
}