Is there a way I can easily change the duration of the transition animation between view controllers? For example if I call dismissModalViewControllerAnimated:YES can I also give an option to control how long that transition occurs?
Not really. You can, though, tell dismissModalViewControllerAnimated to not animate, and then animate yourself using transitionWithView, e.g.,
[UIView transitionWithView:self.view.superview
duration:2.0
options:UIViewAnimationOptionTransitionFlipFromBottom
animations:^{
[self dismissModalViewControllerAnimated:NO];
}
completion:nil];
Obviously, use whatever duration and options work best for you.
Related
I am slowly animating a UIImageView from one image to another. Like so:
[UIView transitionWithView:self.backgroundView duration:30 options:UIViewAnimationOptionTransitionCrossDissolve animations:^{
self.backgroundView.image = endImage;
} completion:nil];
Is there some way to terminate the animation partway through, in response to an event?
A certain Tim Oliver tells me this is how you do it:
[self.backgroundView.layer removeAllAnimations];
You can also retrieve the frame the animation ended on using self.layer.presentationLayer.frame, if you need to freeze the view in the partially animated state.
I have a view controller and have a few objects that I have some simply animations hooked up to.
[UIView animateWithDuration:0.25
delay: 10.1
options: UIViewAnimationOptionCurveEaseIn
animations:^{
addNameViewConstraint.constant = 10;
addNameView.alpha = 1.0;
[self.view layoutIfNeeded]; // move
}
completion:nil];
[UIView animateWithDuration:0.25
delay: 0.15
options: UIViewAnimationOptionCurveEaseIn
animations:^{
addEmailViewConstraint.constant = 10;
addEmailView.alpha = 1.0;
[self.view layoutIfNeeded]; // move
}
completion:nil];
When I was using the push segue the animation works fine. But when I switched to using a modal segue the animation stopped working. I increased the delay in the first one to 10.2 seconds thinking that maybe it was animating before I got to see it. I am calling this animation in the viewWillAppear method. Again works if I'm doing a push segue.. but not for modal. Any ideas?
I am calling this animation in the viewWillAppear method
This is a common mistake. viewWillAppear: is too soon to start the animation. The view has not yet appeared so there is nothing to animate. Move the animateWithDuration:... code to viewDidAppear: and all will be well.
This is, however, as you say in your comment, insufficiently satisfying. What you are after is that the modal transition should be happening and your extra animations within the new view should already be happening as the modal view is in the process of appearing. Instead, with viewDidAppear:, the modal view finishes appearing, it settles into place, and then your other animations start, which is not as cool.
One solution might be to move the animations again, this time to viewWillLayoutSubviews. This is trickier because this method gets called a lot. You will need to use a BOOL instance variable as a flag to ensure that your animations run only once. Thus, this should work (I tried it and it seemed fine):
-(void)viewWillLayoutSubviews {
if (!self->didLayout) {
self->didLayout = YES;
[UIView animateWithDuration:0.25 animations:^{
// mess with constraint constants here
[self.subv layoutIfNeeded];
}];
}
}
I am currently working with UICollectionView and after changing the layout from one to another with setCollectionViewLayout:animated: I want to execute some code upon the completion of the animation. Any idea how to achieve that?
Cheers,
Just for the record, there is now a -setCollectionViewLayout:animated:completion: method on UICollectionView, introduced in iOS 7.
I found that to be able to control the animation, rather than using the implicit one with setCollectionViewLayout:animated: you can use a standard UIView animationWithDuration and change the layout in the animations block, like this:
[UIView animateWithDuration:0.4
delay:0
options:UIViewAnimationCurveEaseOut
animations:^{
self.oldView.collectionViewLayout = self.otherLayout;
self.newView.alpha = 1.0;
}
completion:^(BOOL finished){
self.oldView.alpha = 0.0;
self.otherLayout = nil;
}];
I don't know if it is the recommended way to do it but it lets you control the animation and execute code upon completion.
This is how I switch from one UIView to another UIView: self.view = MyView;
How would I fade out a view to my MySecondView?
You can use UIView's build in transition code to cross dissolve between them.
[UIView transitionFromView:self.view toView:MySecondView duration:0.25 options:UIViewAnimationOptionTransitionCrossDissolve completion:^(BOOL finished) {
// What to do when its finished.
}];
You can also use the regular animation options with something like this. I haven't tested this code as I'm not in front of Xcode but I use it all the time for labels and things without default animations.
[UIView animateWithDuration:0.25 animations:^{
[self.view setAlpha:0.0];
self.view = mySecondView;
[self.view setAlpha:1.0];
}];
Please note that it's not a good idea to do things like self.view = MyView to change screens. By the time you get to a few screens, your viewController will be filled with spaghetti code. You should consider presenting new view controllers that manage their views. One way you can do fade is as follows:
Fade the current view to black (with animation)
In the view controller that you are going to push use viewWillAppear to fade the view to black as well
Push/Present the view controller without animations.
Now use the viewDidAppear method of the newly presented view controller to fade in the view (with animation).
I'm looking for a way to implement consecutive animations using nested animation blocks.
Somewhat complicated by happening inside a UIScrollView, the size of three UIImageViews (there are many images, and as I scroll through them I constantly swapping out the images in the UIImageViews).
When a scroll is finished, I want to switch out the image in the (visible) middle UIImageView, three times, then back to the original view. I'm trying it thus:
- (void) doAnimation {
// get the animation frames, along with the current image
NSString *swap1 = #"first.png";
NSString *swap2 = #"second.png";
UIImage *original = currentPage.image;
UIViewAnimationOptions myOptions = UIViewAnimationOptionBeginFromCurrentState | UIViewAnimationOptionAllowUserInteraction;
[UIView animateWithDuration:2.0 delay:2.0 options:myOptions
animations:^{ [currentPage setImage:[UIImage imageNamed:swap1]]; }
completion:^(BOOL finished) {
[UIView animateWithDuration:2.0 delay:2.0 options:myOptions
animations:^{ [currentPage setImage:[UIImage imageNamed:swap2]]; }
completion:^(BOOL finished) {
[UIView animateWithDuration:2.0 delay:2.0 options:myOptions
animations:^{ [currentPage setImage:[UIImage imageNamed:swap1]]; }
completion:^(BOOL finished) {
[currentPage setImage:original]; }]; }]; }];
}
When I run this, there is no duration, no delay, it all happens at once, almost too fast for the eye to see. Could this be because "currentPage" is a UIImageView? (Similar to this question?)
There's no delay because UIImageView.image isn't an animateable property. As such, the UIView animation machinery will have no animations to set up and will just call your completion block immediately.
What sort of animation did you expect? You can attach a CATransition object to the underlying layer to get a simple cross-fade, Just use [imageView.layer addAnimation:[CATransition animation] forKey:nil] to get the crossfade with the default values (you can customize the timing by modifying properties of the CATransition before attaching it to the layer). To achieve the subsequent animations, you can either use the delegate property of CAAnimation (CATransition's superclass) to learn when it's done and fire your second one, or you could just use -performSelector:withObject:afterDelay: to start your next animation step after a user-defined delay. The delegate method is going to be more accurate with regards to timing, but the performSelector method is a bit easier to write. Sadly, CAAnimation doesn't support a completion block.
Another approach for you to transition from one image view to another is by using the block animation function transitionFromView:toView:duration:options:completion as discussed in "Creating Animated Transitions Between Views". You would do this instead of animateWithDuration to change images.