View animation issue - ios

Question

I'm trying to flip animate a view into another view, which corresponds of a small section of the screen. Both views have the same dimensions and center.
I keep getting as a result the animation of the full screen. From the code below, can somebody please let me know what the heck i'm doing wrong?
Thank you,
-j
+ (void) flipView:(UIView*)viewA toView:(UIView*)viewB wait:(Boolean)wait
{
// get parent view
UIView *parent = [viewA superview];
CGRect r = viewA.frame;
// create container view with the same dimensions as ViewA
UIView *containerView = [[UIView alloc] initWithFrame:viewA.bounds];
containerView.center = viewA.center;
// attache both views to intermidiate view
[containerView addSubview:viewA];
[containerView addSubview:viewB];
[viewA removeFromSuperview];
[parent addSubview:containerView];
viewB.alpha = 0;
viewA.alpha = 1;
// Perform the annimation
__block BOOL done = NO;
[UIView transitionWithView:viewA
duration:2.0
options: (UIViewAnimationOptionTransitionFlipFromTop)
animations:^{
viewA.alpha = 0;
viewB.alpha = 1; }
completion:^(BOOL finished) {
done = YES;
// detach all views
[viewA removeFromSuperview];
[viewB removeFromSuperview];
[containerView removeFromSuperview];
}
];
if(wait) {
while (done == NO)
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];
}
}

Answer 1

First get rid of the old animation code (or at least commit it), it should look like this:
+ (void) flipView:(UIView*)viewA toView:(UIView*)viewB wait:(BOOL)wait
{
viewB.alpha = 0;
viewA.alpha = 1;
__block BOOL done = NO;
[UIView transitionWithView:viewA
duration:2.0
options: (UIViewAnimationOptionTransitionFlipFromTop)
animations:^{
viewA.alpha = 0;
viewB.alpha = 1; }
completion:^(BOOL finished) {
done = YES;
}
];
if(wait) {
while (!done)
[[NSRunLoop currentRunLoop] runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0.1]];
}
}
Second, the superview of the subview that you want to transition is actually going to get the transition. So this means that you'll have to add viewA and viewB to a subview, add this subview to another view and then do the animation.

Answer 2

Here is a solution without any hacks with runloop. Just use the first message to run a transition to another view, and the second message to return to original state:
- (void) forwardTransitionFromView: (UIView *) viewA toView: (UIView *) viewB
{
NSAssert(viewA.superview, #"The 'from' view should be added to a view hierarchy before transition");
NSAssert(!viewB.superview, #"The 'to' view should NOT be added to a view hierarchy before transition");
CGSize viewASize = viewA.bounds.size;
viewB.frame = CGRectMake(0.0, 0.0, viewASize.width, viewASize.height);
[UIView transitionWithView:viewA
duration:1.0
options:UIViewAnimationOptionTransitionFlipFromRight
animations:^{
[viewA addSubview:viewB];
}
completion:NULL];
}
- (void) backwardTransitionFromView: (UIView *) viewB toView: (UIView *) viewA
{
NSAssert([viewB.superview isEqual:viewA], #"The 'from' view should be a subview of 'to' view");
[UIView transitionWithView:viewA
duration:1.0
options:UIViewAnimationOptionTransitionFlipFromLeft
animations:^{
[viewB removeFromSuperview];
}
completion:NULL];
}

Answer 3

Why dont you flip both views in same direction?
-(void) FlipView:(bool) fromRight {
if(fromRight) {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.75];
[UIView setAnimationDelegate:self];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:view1 cache:YES];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:view2 cache:YES];
[UIView commitAnimations];
}
else {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:0.75];
[UIView setAnimationDelegate:self];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:view1 cache:YES];
[UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:view2 cache:YES];
[UIView commitAnimations];
}
}
and call the method like below:
[view1 setHidden:NO];
[self FlipView:YES];
[view2 setHidden:YES];
to reverse the animation:
[view2 setHidden:NO];
[self FlipView:NO];
[view1 setHidden:YES];