Present formsheet modal ViewController using horizontal flip - cocoa-touch

Question

I currently show a modal UIViewController in the formSheet style that was presented with the coverVertical animation. I am trying to present another modal UIViewController from it, using currentContext for the presentation style and flipHorizontal for the animation style. It does work, but there is a solid white white background behind the flip as it occurs. Any advice on how to successfully present another formsheet modal UIViewController using the flipHorizontal style from a pre-existing modal UIViewController in the formSheet style would be appreciated please! Thanks
Code:
// Loading of first modalVC
- (void)showModalVC {
Modal1VC *modal1VC = [[Modal1VC alloc] init];
modal1VC.modalPresentationStyle = UIModalPresentationFormSheet;
modal1VC.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self presentModalViewController:modal1VC animated:YES];
[modal1VC release];
modal1VC.view.superview.bounds = CGRectMake(0, 0, 400, 400);
}
// Loading of second modalVC in Modal1VC
- (void)buttonTapped:(id)sender {
UIViewController *modal2VC = [[UIViewController alloc] init];
modal2VC.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
modal2VC.modalPresentationStyle = UIModalPresentationCurrentContext;
modal2VC.view.backgroundColor = [UIColor greenColor];
[self presentModalViewController:modal2VC animated:YES];
[modal2VC release];
modal2VC.view.superview.bounds = CGRectMake(0, 0, 400, 400);
}

Answer 1

UIViewController *presentingViewController = //allocate your VC
[modalViewController setModalTransitionStyle:UIModalTransitionStyleFlipHorizontal];
UIViewController *modalViewController = //your modal VC
[presentingViewController presentModalViewController:modalViewController animated:YES];
This is all the code you need ;)

Answer 2

It sounds like your transition is working, but the white background shown on the flip transition is the problem?
During the flip transition, the white background that is shown is actually the window. You can change the color that is shown by setting the backgroundColor property of window in the AppDelegate.

Answer 3

That would seem to be a limitation of presentModalViewController:animated:.
Instead of [self presentModalViewController:modal2VC animated:YES], you may be able to get the effect you want using UIView animations. Perhaps something like this:
[UIView transitionWithView:self.view.window
duration:0.3
options:UIViewAnimationOptionTransitionFlipFromRight
animations:^{
[self presentModalViewController:modal2VC animated:NO];
} completion:NULL];