change counterclockwise to clockwise with CGAffineTransformIdentity - iphone

Question

I have a telephone wheel. On the touchend, it goes to his position with an animation.
Until the angle is less than 180°, it returns clockwise. No problem, with this code :
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView beginAnimations:nil context:NULL];
[UIViewsetAnimationDuration:0.5];
wheel.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
}
But It goes wrong after that and continue to rotate for a complet turn.
I tried to make to animations like this :
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.2];
wheel.transform = CGAffineTransformRotate(wheel.transform, degreesToRadians(-130));
[UIView commitAnimations];
[self performSelector:#selector(animatewheelViewToCenter) withObject:nil afterDelay:0.3];
}
- (void)animatewheelViewToCenter{
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView beginAnimations:nil context:NULL];
[UIViewsetAnimationDuration:0.3];
wheel.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
}
It works, but the animation isn't fluid ; the change is visible.

Answer 1

I'm not sure what the state is when touchesEnded (in terms of rotation) and I'm assuing you chose degreesToRadians(-130) to try and do it partially and expect the next method to do the rest. This should be a better solution that hopefully yields the result you're expecting. I'm not sure what cadran is or why you're rotating that, so I'll just rotate the wheel.
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.2];
wheel.transform = CGAffineTransformMakeRotation(degreesToRadians(-130));
// I would recommend that the degrees you rotate be half of whatever your rotation is.
// this would make the wheel rotate to the home position more evenly
[UIView setAnimationDelegate:self];
[UIView setAnimationDidStopSelector:#selector(animatewheelViewToCenter:finished:context:)];
[UIView commitAnimations];
}
- (void)animatewheelViewToCenter:(NSString *)animationID finished:(NSNumber *)finished context:(id)context {
[UIView setAnimationBeginsFromCurrentState:YES]; // you might need to make this NO
[UIView beginAnimations:nil context:NULL];
[UIViewsetAnimationDuration:0.2];
wheel.transform = CGAffineTransformIdentity;
[UIView commitAnimations];
}
EDIT: Actually, I would probably make the rotation (in the example -130 degrees) slightly more than what half would be, because CGAffineTransformIdentity is gonna take the shortest path to go back to regular, so if you go exactly 1/2 way, it may not go the correct direction (clockwise or counter-clockwise) that you want.