IOS animated pulsing circle like blue ball on maps

Question

I'd like to know how to implement the blue ball with the pulsating ring of current location in maps, but without a mapview.

Basically I'd like to know the best way to have a blue ball with a pulsating ring on a normal UIView (or my custom view) whenever the user touches the screen, with that touch being the center of the blue ball.

I have 2 ideas, first I could implement an animation, which I was not able to do, but it is probably possible. Second I could get a sequence of images, like a gif, and display it wherever the user touches.

Which one is the best option? Or is there a better option?

Thank you.

Answer 1

Try this:

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(200, 200, 100, 100)];
view.backgroundColor = [UIColor blueColor];
view.layer.cornerRadius = 50;

[self.view addSubview:view];

CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale"];
scaleAnimation.duration = 0.2;
scaleAnimation.repeatCount = HUGE_VAL;
scaleAnimation.autoreverses = YES;
scaleAnimation.fromValue = [NSNumber numberWithFloat:1.2];
scaleAnimation.toValue = [NSNumber numberWithFloat:0.8];

[view.layer addAnimation:scaleAnimation forKey:@"scale"];

Set the parameters as you like, to modify the effect.

Edit:

You have to add the QuartzCore framework, and include <QuartzCore/QuartzCore.h> for this to work.