iOS: Push animation done programatically

ios_push_anim.m

- (void)viewWillAppear:(BOOL)animated
{
	[super viewWillAppear:NO];

	CATransition *animation = [CATransition animation];
	
	[animation setDelegate:self];
	[animation setType:kCATransitionPush];
	[animation setSubtype:kCATransitionFromRight];
	
	[animation setDuration:0.40];
	[animation setTimingFunction:
	 [CAMediaTimingFunction functionWithName:
	  kCAMediaTimingFunctionEaseInEaseOut]];
	
	[self.view.layer addAnimation:animation forKey:kCATransition];
}


- (IBAction) close
{
	CATransition *animation = [CATransition animation];
	
	[animation setDelegate:self];
	[animation setType:kCATransitionPush];
	
	// the fact that i only need this for close probably
	// indicates that i am doing something wrong
	switch (self.interfaceOrientation)
	{
		case UIInterfaceOrientationPortrait:
			[animation setSubtype:kCATransitionFromLeft];
			break;
		case UIInterfaceOrientationPortraitUpsideDown:
			[animation setSubtype:kCATransitionFromRight];
			break;
		case  UIInterfaceOrientationLandscapeLeft:
			[animation setSubtype:kCATransitionFromTop];
			break;
		case  UIInterfaceOrientationLandscapeRight:
			[animation setSubtype:kCATransitionFromBottom];
			break;			
	}
	
	[animation setDuration:0.40];
	[animation setTimingFunction:
	 [CAMediaTimingFunction functionWithName:
	  kCAMediaTimingFunctionEaseInEaseOut]];
	
	[self.view.window.layer addAnimation:animation forKey:kCATransition];			
	[self dismissModalViewControllerAnimated:NO];
}