Pulse view

gistfile1.m

+ (void)pulseView:(UIView *)view completion:(void (^)(void))block {

	// if you use auto layout, view-based transform go haywire, as they trigger layoutSubviews
	// consequence is that you have no idea where the view will end up on the screen once animation completes
	// see this discussion: http://stackoverflow.com/questions/12943107/how-do-i-adjust-the-anchor-point-of-a-calayer-when-auto-layout-is-being-used

	// thus (per solution 4 from link above), rewriting with CAKeyframeAnimation

	CAKeyframeAnimation *ka = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
	ka.duration = .49;
	ka.keyTimes = @[@(.102), @(.347), @(.551), @(.735), @(.898), @(1.0)];
	ka.values = @[
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(0.7, 0.7))],
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(1.25, 1.25))],
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(0.9, 0.9))],
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(1.05, 1.05))],
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(0.95, 0.95))],
		[NSValue valueWithCATransform3D:CATransform3DMakeAffineTransform(CGAffineTransformMakeScale(1.0, 1.0))]
	];
	ka.removedOnCompletion = YES;
	ka.repeatCount = 1;
	ka.fillMode = kCAFillModeForwards;
	ka.autoreverses = NO;
	
	if (block == NULL) {
		[view.layer addAnimation:ka forKey:@"transform"];
		
	} else {
		[CATransaction begin];
		[CATransaction setCompletionBlock:block];
		[view.layer addAnimation:ka forKey:@"transform"];
		[CATransaction commit];
	}
}