I have a little UIVIew which is out of the current main view, and I use this code to show it:
[UIView animateWithDuration:0.4
delay:0.0
options: UIViewAnimationOptionTransitionNone
animations:^{
// menuView.center = CGPointMake(menuView.center.x+213, menuView.center.y);
self.view.center = CGPointMake(self.view.center.x+215, self.view.center.y);
}
completion:^(BOOL finished){
}];
And the problem is I can't interact with this view. I have few button on it and they are not clickable... what is the problem?
The Core Animation takes a 'snapshot' of the view and manipulates with a single image, allowing graphic card acceleration. If you want to interact with the view, while it's moving, you'll probably need to make your own animation using a timer and slowly moving the view. It will be CPU-intensive as all the computation will be done by the CPU and not GPU.
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 am not much into iOS animation. What I am trying to achieve is a simple message view that slide vertical from bottom of screen to a given y, then after few instants the UIView rollback in vertical to go off screen.
[UIView animateWithDuration:0.5f
animations:^{
self.messageView.frame=CGRectMake(x, y -80, width, height);
}
completion:^(BOOL finished){
if (finished) {
[UIView animateWithDuration:0.5f delay:2.0f options:UIViewAnimationOptionCurveLinear
animations:^{
self.messageView.frame=CGRectMake(x, y + 80, width, height);
}
completion:^(BOOL finished){
// do something...
}
];
}
} ];
This is working fine, but I am having a problem using this mechanism in a iOS UITabBar application: when I change tab, the animation stop, I can infact see that "finished" completion is "false". Therefore the second block is not called, and the message view stays on.
Here are the questions:
my first concern is to understand if the code I have written is correct, regarding the nested animations.
I could solve by ignoring 'finished' and execute code anyway, but I don't feel it is a good idea
within the last completion block, I have put some programming logic, basically I am restoring few UIButtons state, and some other little UI change. At this point I don't know if it is a good idea, it seems not, but how can let the UI knows that the message view has disappeared. NSNotification and KVO seems a bad idea when fast responsive UI change are involved.
You can stop all animations for a layer by sending the layer a removeAllAnimations message.
[sel.view removeAllAnimations];
I have a UIViewController which has multiple subviews. Each subview is a UIView subclass, and I want to switch between views by tapping the toolbar buttons. I did this by using the animation blocks:
Example:
[UIView animateWithDuration:0.5
delay:0.0
options:UIViewAnimationOptionTransitionFlipFromRight
animations:^{
[StoreView removeFromSuperview];
[self.view addSubview:HomeView];
}
completion:NULL];
Everything is working fine actually. The problem is the transition is not really smooth. For example, the HomeView has five buttons scattered (as part of the design), and whenever I switch from one view to HomeView, these buttons will come from a corner and rearrange itself after the transition, which is not exactly beautiful to look at.
So how will I make these buttons stay in place?
When doing animations with complex subviews you can sometimes get undesirable results as you are experiencing. Not only can some oddities appear, but they are sometimes costly depending on the complexity of the view structure. One suggestion I would make is instead of animating the complex views themselves, you could render the views to a graphics context and animate the resulting image in a UIImageView, using sleight-of-hand to make it appear that you are animating the view hierarchy. In this effect, you avoid doing what amounts to a complex transform on the HomeView and StoreView and instead do simple flip with UIImageView instances. Consider the following example code:
UIImageView *storeImage = // pointer to the image rendered to a graphics context
UIImageView *homeImage = // pointer to the image rendered to a graphics context
[self.view addSubview:storeImage];
[storeView removeFromSuperview];
[UIView animateWithDuration:0.5
delay:0.0
options:UIViewAnimationOptionTransitionFlipFromRight
animations:^{
[storeImage removeFromSuperview];
[self.view addSubview:homeImage];
}
completion:^(BOOL finished) {
[self.view addSubview:homeView];
[homeImage removeFromSuperview];
}];
Same code as in a previous question, but a different issue.
I've created a custom animation to add a view controller to a UINavigationController. This code scales a view to 80% the original size, then flips it, then scales it back up to its original size:
[UIView animateWithDuration:scaleDuration delay:0 options:UIViewAnimationOptionCurveEaseIn animations:^{
// Scale the controllers' views down.
self.view.transform = CGAffineTransformScale(self.view.transform, 0.8, 0.8);
} completion:^(BOOL finished) {
// Transition to the new view and push on the new view controller.
[UIView transitionWithView:self.view duration:1 options:UIViewAnimationOptionCurveLinear | UIViewAnimationOptionTransitionFlipFromLeft animations:^{
[self pushViewController:viewController animated:NO];
} completion:^(BOOL finished) {
[UIView animateWithDuration:scaleDuration delay:0 options:UIViewAnimationOptionCurveLinear animations:
^{
// Scale back to the original size.
self.view.transform = CGAffineTransformScale(self.view.transform, 1.25, 1.25);
} completion:nil];
}];
}];
The issue is that, when the animation completes, the new view is displayed very nicely, except that it is drawn under the task bar. That is, it draws in at screen origin 0,0, rather than 0,20. The "Status Bar" option is set in IB (to "Black"), and, naturally, this does not happen if I use a standard UINavigationController push animation, only my custom one. If I rotate the device after the animation, the redraw on rotation moves it to the proper place. But how do I get it to do that in the first place?
As an added wrinkle, it does not draw under the task bar if I move the pushViewController:animated: call a line down to the completion: block (though then the view appears to flip to itself and then suddenly show the new view, of course).
I found the only work around so far is hide the navigationbar and then show it.
after you set your transform, add following 2 lines:
[self setNavigationBarHidden:YES];
[self setNavigationBarHidden:NO];
It's ugly but works, I am also looking for a better solution.
note: layoutsubview, setNeedsLayout won't work.
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.