iPhone iOS how to make UIRotationGestureRecognizer and UIPinchGestureRecognizer to work together to scale and rotate a UIView with subviews?

Question

I\'m implementing a drag/drop/resize/rotate labels within my app. So far everything is working except for the UIRotationGestureRecognizer gesture. More specifically

Answer 1

If you want two gestureRecognisers to run in parallel (simultaneously) your view should implement <UIGestureRecognizerDelegate>.

Also, you should make it a delegate of both gestureRecognizers.

rotationGestureRecognizer.delegate=self;
pinchGestureRecognizer.delegate=self;

And you also should implement shouldRecognizeSimultaneouslyWithGestureRecognizer: method:

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {

    return YES;
}

NOTE: if you have more then this two gestureRecognisers in your view you're gonna have to add some identity checking in this method.

EDIT:

Just found Ole Begemann's article on this topic: Gesture Recognition on iOS with Attention to Detail