-(void)applicationDidFinishLaunching: (UIApplication *)application
{
// Create the two views to transition between, and add them to our containerView. We'll hide the second one
// until we are ready to transition to it.
UIImage *image1 = [UIImage
imageWithContentsOfFile:[[NSBundle
mainBundle] pathForResource:@"image1.jpg"
ofType:nil]];
view1 = [[UIImageView alloc] initWithImage:image1];
UIImage *image2 = [UIImage
imageWithContentsOfFile:[[NSBundle
mainBundle] pathForResource:@"image2.jpg"
ofType:nil]];
view2 = [[UIImageView alloc] initWithImage:image2];
view2.hidden = YES;
[containerView
addSubview:view1];
[containerView
addSubview:view2];
transitioning = NO;
}
-(void)dealloc
{
[containerView
release];
[view1
release];
[view2
release];
[super
dealloc];
}
-(void)performTransition
{
// First create a CATransition object to describe the transition
CATransition *transition = [CATransition
animation];
// Animate over 3/4 of a second
transition.duration = 0.75;
// using the ease in/out timing function
transition.timingFunction = [CAMediaTimingFunction
functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
// Now to set the type of transition. Since we need to choose at random, we'll setup a couple of arrays to help us.
NSString *types[4] = {kCATransitionMoveIn, kCATransitionPush, kCATransitionReveal, kCATransitionFade};
NSString *subtypes[4] = {kCATransitionFromLeft, kCATransitionFromRight, kCATransitionFromTop,kCATransitionFromBottom};
int rnd = random() % 4;
transition.type = types[rnd];
if(rnd < 3) // if we didn't pick the fade transition, then we need to set a subtype too
{
transition.subtype = subtypes[random() % 4];
}
// Finally, to avoid overlapping transitions we assign ourselves as the delegate for the animation and wait for the
// -animationDidStop:finished: message. When it comes in, we will flag that we are no longer transitioning.
transitioning = YES;
transition.delegate = self;
// Next add it to the containerView's layer. This will perform the transition based on how we change its contents.
[containerView.layer addAnimation:transition forKey:nil];
// Here we hide view1, and show view2, which will cause Core Animation to animate view1 away and view2 in.
view1.hidden = YES;
view2.hidden = NO;
// And so that we will continue to swap between our two images, we swap the instance variables referencing them.
UIImageView *tmp = view2;
view2 = view1;
view1 = tmp;
}
-(void)animationDidStop: (CAAnimation *)theAnimation finished: (BOOL)flag
{
transitioning = NO;
}
-(IBAction)nextTransition: (id)sender
{
if(!transitioning)
{
[self
performTransition];
}
}