How to animate dismissal of one view Controller to another using custom animation? - xcode4.5

Question

I just figure out how to animate insertion of one viewControll
[self transitiontoViewController:self.filterController duration:.5 options:UIViewAnimationOptionTransitionNone animations:^{
[self.filterController.view resizeandMovewithRect:CGRectMake(0, self.filterController.view.frame.size.height, 0, 0)];
} completion:^(BOOL finished){
}];
Here, resizeAndMovewithRect simply move a view around using this category for UIView
-(void) resizeandMovewithRect:(CGRect)movement
{
CGRect myFrame = self.frame;
CGRect newFrame = CGRectMake(myFrame.origin.x+movement.origin.x, myFrame.origin.y + movement.origin.y, myFrame.size.width + movement.size.width , myFrame.size.height + movement.size.height);
self.frame =newFrame;
}
Now I want to do the opposite. I want self.filterController to be dismissed by moving it off screen.
One way to do so is:
[self transitiontoViewController:self.filterController duration:.5 options:UIViewAnimationOptionTransitionNone animations:^{
[self.filterController.view resizeandMovewithRect:CGRectMake(0, -self.filterController.view.frame.size.height, 0, 0)];
} completion:^(BOOL finished){
}];
If I do this the animation is not drawn at all.
It seems to me that self.filterController is removed from superview at the beginning of the animation. That's why whatever happen to self.filterController is not seen. So I do it this way
[UIView animateWithDuration:.5 animations:^{
[self.filterController.view resizeandMovewithRect:CGRectMake(0, -self.filterController.view.frame.size.height, 0, 0)];
} completion:^(BOOL finished){
[self transitiontoViewController:self.last2ViewsInTheContainer[0] duration:0 options:UIViewAnimationOptionTransitionNone animations:^{
} completion:nil];
}];
So I animate rolling up self.filterController.view first before I call [self transitiontoViewController
However, if I do it this way, then by the time the self.filterController.view is rolled up, the view that's replacing it is not added yet to superview. So that one is not seen.
How should I do it anyway?

Answer 1

I have found the answer. Turns out no views are removed till the end. The issue is that the new viewController is added to the top of the stack.
So when adding self.filterController, things are simple. It's already in front while the from view is in the back.
When pulling out self.filterController, that backView is in front hiding self.filterController. So the solution is to simply readd self.filterController to the superview and we'll see the animation.
Final code:
[self transitiontoViewController:self.last2ViewsInTheContainer[0] duration:.5 options:UIViewAnimationOptionTransitionNone animations:^{
[self.filterController.view.superview addSubview:self.filterController.view]; //Put the filterControllerView at the front
[self.filterController.view resizeandMovewithRect:CGRectMake(0, -self.filterController.view.frame.size.height, 0, 0)];
} completion:nil];