iOS - How do I perform two transitions sequentially? - ios

Question

I have taken some code from other SO questions, but I must be doing something wonky. The app jumps from the first view to the third. What I'm trying to achieve is:
ViewController 1 Image 1 - loads with an image. Quickly cross-disolves into ViewController 1 image 2.
ViewController 1 Image 2 - flips to ViewController 2.
The cross-disolve happens but takes me to VC2. I've battered at this for most of the day. It's time to ask for help while I go sit in a bathtub.
Here's what I've been doing:
- (void)viewDidLoad
{
NSLog(#"%s", __FUNCTION__);
[super viewDidLoad];
}
- (void)viewDidAppear:(BOOL)animated {
NSLog(#"%s", __FUNCTION__);
sleep (2);
[self transition1]; //showing image 1
}
- (void) transition1 {
NSLog(#"%s", __FUNCTION__);
/*
[UIView transitionFromView:firstView
toView:secondView
duration:3.0
options:UIViewAnimationOptionTransitionCrossDissolve
completion:^(BOOL finished) {
[firstView removeFromSuperview];
}];
*/
//this transition doesn't happen
UIImage * secondImage = [UIImage imageNamed:#"image2.png"];
[UIView transitionWithView:self.firstView
duration:5.0f
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
self.imageView.image = secondImage;
} completion:NULL];
sleep (2);
[self transition2];
}
- (void) transition2 {
NSLog(#"%s", __FUNCTION__);
self.patterns = [[PatternViewController alloc] initWithNibName:#"PatternView_iPad" bundle:nil];
self.patterns.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentViewController:patterns animated:YES completion:nil];
}
Thanks for any help.
UPDATE
I've updated my code per Moxy's suggestions as follows:
- (void)viewDidAppear:(BOOL)animated {
NSLog(#"%s", __FUNCTION__);
[self performSelector:#selector(transition1)
withObject:nil
afterDelay:2.0f];
}
-(void)transition1
{
NSLog(#"%s", __FUNCTION__);
UIImage * secondImage = [UIImage imageNamed:#"image2.png"];
[UIView transitionWithView:self.firstView
duration:5.0f
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
self.imageView.image = secondImage;
}
completion:^(BOOL finished){
[self performSelector:#selector(transition2)
withObject:nil
afterDelay:2.0f];
}];
}
-(void)transition2
{
NSLog(#"%s", __FUNCTION__);
self.patterns = [[PatternViewController alloc] initWithNibName:#"PatternView_iPad"
bundle:nil];
self.patterns.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentViewController:patterns
animated:YES
completion:nil];
}

Answer 1

All you need to do is to start your second animation in the first animation's completion block.
Sleep() is something you probably shouldn't be using.
-(void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
NSLog(#"%s", __FUNCTION__);
[self performSelector:#selector(transition1)
withObject:nil
afterDelay:2.0f]
}
-(void)transition1
{
NSLog(#"%s", __FUNCTION__);
UIImage * secondImage = [UIImage imageNamed:#"image2.png"];
[UIView transitionWithView:self.firstView
duration:5.0f
options:UIViewAnimationOptionTransitionCrossDissolve
animations:^{
self.imageView.image = secondImage;
}
completion:^(BOOL finished){
[self performSelector:#selector(transition2)
withObject:nil
afterDelay:2.0f]
}];
}
-(void)transition2
{
NSLog(#"%s", __FUNCTION__);
self.patterns = [[PatternViewController alloc] initWithNibName:#"PatternView_iPad"
bundle:nil];
self.patterns.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentViewController:patterns
animated:YES
completion:nil];
}