Using cgaffinetransformmakescale and cgaffinetransformmakerotation deforms my view - objective-c

Question

I have a simple UIView:
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
view.backgroundColor = [UIColor greenColor];
[self.view addSubview:view];
self.someView = view;
Then I do this
[UIView animateWithDuration:10
delay:1
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
self.someView.center = CGPointMake(CGRectGetWidth(self.view.bounds) - CGRectGetWidth(self.someView.frame) / 2, 150);
CGAffineTransform transform = CGAffineTransformMakeRotation(M_PI);
self.someView.transform = CGAffineTransformScale(transform, 2, 0.5);
}
completion:^(BOOL finished) {
}];
While is executed this simple animation, someView is deformed. As far as I know it should rotate and change it's size. I can't understand why is it happening so, how can i fix it?
Thanks

Answer 1

The problem is animating a combined scaling and rotation. The end result is the same as animating them separately, but the frames in between are not easily defined. So the animation framework makes a guess, and it is not what you are expecting.
If you want the animation to show a rotation and scaling separately, you need to apply them separately to the view hierarchy. For example:
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
view.backgroundColor = [UIColor greenColor];
[self.view addSubview:view];
self.someView = view;
UIView *innerView = [[UIView alloc] initWithFrame:view.bounds];
innerView.backgroundColor = [UIColor blueColor];
[view addSubview:innerView];
self.someInnerView = innerView;
The animation splits the transform:
[UIView animateWithDuration:10
delay:1
options:UIViewAnimationOptionCurveEaseInOut
animations:^{
self.someView.center = CGPointMake(CGRectGetWidth(self.view.bounds) - CGRectGetWidth(self.someView.frame) / 2, 150);
self.someView.transform = CGAffineTransformMakeRotation(M_PI);
self.someInnerView.transform = CGAffineTransformMakeScale(2, 0.5);
}
completion:^(BOOL finished) {
}];