I have two animations running; show search bar and show banner. Both those animations are resizing the same view and if they are running on the same time (Which they are) the latest animation will cancel the resize. Is there anyway to check if UIView is currently animating and then standby for animation?
I'm pretty sure I'm not using CAAnimations, since Cocoa not is detecting such class.
This one is running when an ad was received. Unfortunately, that is the same time as ShowSearch is running.
- (void)adViewDidReceiveAd:(GADBannerView *)bannerView {
if (!hasloaded) {
[UIView beginAnimations:nil context:nil];
[UIView setAnimationCurve: UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration: 1.0];
[bannerView_ setFrame:CGRectMake(0, self.view.frame.size.height, bannerView_.frame.size.width, bannerView_.frame.size.height)];
// move and grow
[bannerView_ setFrame:CGRectMake(0, self.view.frame.size.height-50, bannerView_.frame.size.width, bannerView_.frame.size.height)];
// set original position
[UIT setFrame:CGRectMake(UIT.frame.origin.x, UIT.frame.origin.y, UIT.frame.size.width, UIT.frame.size.height)];
// move and grow
[UIT setFrame:CGRectMake(UIT.frame.origin.x, UIT.frame.origin.y, UIT.frame.size.width, UIT.frame.size.height-50)];
[UIView commitAnimations];
hasloaded = true;
}
}
You can use the completion block in the UIView method +animateWithDuration:animations:completion: (which is a more modern alternative to beginAnimations/commitAnimations) to chain multiple animations (I'm guessing this is what you want to do?).
If you select your code while entering it and press control + K, you will preserve formatting and make it pretty. Try it. Reading the wall of text made from pasting code into a true-type non-color-formatted environment.
Nick Weaver says:
A UIView has a layer (CALayer). You can send animationKeys to it which will give you an array of keys which identify the animations attached to the layer. I suppose that if there are any entries, the animation(s) are running. If you want to dig even deeper have a look at the CAMediaTiming protocol which CALayer adopts. It does some more information on the current animation.
Related
Here's something I don't find to be logical:
When animating the property of a UIView (in this case mainView) the funciton is called on the generic type, instead of on the specific Instance of UIView
UIView.animate(withDuration: flashDuration, delay: 0, options: UIViewAnimationOptions.allowUserInteraction, animations: {
self.mainView.backgroundColor = self.black
}, completion: nil)
This is quite useful, because I can now animate different instances of UIView in the same place, but how is it possible to call a function on a generic type?
I have never came across this anywhere else in Swift.
I don't know what exactly happens under the hood because UIKit isn't open-source
Before the block-based UIView animation methods were introduced, animating views looked like this, and those methods are actually still available:
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:duration];
myView.center = CGPointMake(300, 300);
[UIView commitAnimations];
Knowing this, we could implement our own block-based animation method like this:
(void)my_animateWithDuration:(NSTimeInterval)duration animations:(void (^)(void))animations
{
[UIView beginAnimations:nil context:nil];
[UIView setAnimationDuration:duration];
animations();
[UIView commitAnimations];
}
The actual animation is performed by Core Animation, which works at the layer level – each UIView has a backing CALayer instance that is responsible for animations and compositing, while the view mostly just handles touch events and coordinate system conversions.
I won't go into detail here on how Core Animation works, you might want to read the Core Animation Programming Guide for that. Essentially, it's a system to animate changes in a layer tree, without explicitly calculating every keyframe (and it's actually fairly difficult to get intermediate values out of Core Animation, you usually just specify from and to values, durations, etc. and let the system take care of the details).
I have UIScrollView subclass. Its content is reusable - about 4 or 5 views are used to display hundreds of elements (while scrolling hidden objects reused and jumps to another position when its needed to see them)
What i need: ability to automatically scroll my scroll view to any position. For example my scroll view displays 4th, 5th and 6th element and when I tap some button it needs to scroll to 30th element. In other words I need standard behaviour of UIScrollView.
This works fine:
[self setContentOffset:CGPointMake(index*elementWidth, 0) animated:YES];
but I need some customisation. For example, change animation duration, add some code to perform on end of animation.
Obvious decision:
[UIView animateWithDuration:3 delay:0 options:UIViewAnimationOptionBeginFromCurrentState animations:^{
[self setContentOffset:CGPointMake(index*elementWidth, 0)];
} completion:^(BOOL finished) {
//some code
}];
but I have some actions connected to scroll event, and so now all of them are in animation block and it causes all subview's frames to animate too (thanks to few reusable elements all of them animates not how i want)
The question is: How can I make custom animation (in fact I need custom duration, actions on end and BeginFromCurrentState option) for content offset WITHOUT animating all the code, connected to scrollViewDidScroll event?
UPD:
Thanks to Andrew's answer(first part) I solved issue with animation inside scrollViewDidScroll:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView{
[UIView performWithoutAnimation:^{
[self refreshTiles];
}];
}
But scrollViewDidScroll must (for my purposes) executes every frame of animation like it was in case of
[self setContentOffset:CGPointMake(index*elementWidth, 0) animated:YES];
However, now it executes only once at start of animation.
How can I solve this?
Did you try the same approach, but with disabled animation in scrollViewDidScroll ?
On iOS 7, you could try wrapping your code in scrollViewDidScroll in
[UIView performWithoutAnimation:^{
//Your code here
}];
on previous iOS versions, you could try:
[CATransaction begin];
[CATransaction setDisableActions:YES];
//Your code here
[CATransaction commit];
Update:
Unfortunately that's where you hit the tough part of the whole thing. setContentOffset: calls the delegate just once, it's equivalent to setContentOffset:animated:NO, which again calls it just once.
setContentOffset:animated:YES calls the delegate as the animation changes the bounds of the scrollview and you want that, but you don't want the provided animation, so the only way around this that I can come up with is to gradually change the contentOffset of the scrollview, so that the animation system doesn't just jump to the final value, as is the case at the moment.
To do that you can look at keyframe animations, like so for iOS 7:
[UIView animateKeyframesWithDuration:duration delay:delay options:options animations:^{
[UIView addKeyframeWithRelativeStartTime:0.0 relativeDuration:0.5 animations:^{
[self setContentOffset:CGPointMake(floorf(index/2) * elementWidth, 0)];
}];
[UIView addKeyframeWithRelativeStartTime:0.5 relativeDuration:0.5 animations:^{
[self setContentOffset:CGPointMake(index*elementWidth, 0)];
}];
} completion:^(BOOL finished) {
//Completion Block
}];
This will get you two updates and of course you could use some math and a loop to add up a lot more of these with the appropriate timings.
On previous iOS versions, you'll have to drop to CoreAnimation for keyframe animations, but it's basically the same thing with a bit different syntax.
Method 2:
You can try polling the presentationLayer of the scrollview for any changes with a timer that you start at the beginning of the animation, since unfortunately the presentationLayer's properties aren't KVO observable. Or you can use needsDisplayForKey in a subclass of the layer to get notified when the bounds change, but that'll require some work to set up and it does cause redrawing, which might affect performance.
Method 3:
Would be to dissect exactly what happens to the scrollView when animated is YES try and intercept the animation that gets set on the scrollview and change its parameters, but since this would be the most hacky, breakable due to Apple's changes and trickiest method, I won't go into it.
A nice way to do this is with the AnimationEngine library. It's a very small library: six files, with three more if you want damped spring behavior.
Behind the scenes it uses a CADisplayLink to run your animation block once every frame. You get a clean block-based syntax that's easy to use, and a bunch of interpolation and easing functions that save you time.
To animate contentOffset:
startOffset = scrollView.contentOffset;
endOffset = ..
// Constant speed looks good...
const CGFloat kTimelineAnimationSpeed = 300;
CGFloat timelineAnimationDuration = fabs(deltaToDesiredX) / kTimelineAnimationSpeed;
[INTUAnimationEngine animateWithDuration:timelineAnimationDuration
delay:0
easing:INTULinear
animations:^(CGFloat progress) {
self.videoTimelineView.contentOffset =
INTUInterpolateCGPoint(startOffset, endOffset, progress);
}
completion:^(BOOL finished) {
autoscrollEnabled = YES;
}];
Try this:
UIView.animate(withDuration: 0.6, animations: {
self.view.collectionView.contentOffset = newOffset
self.view.layoutIfNeeded()
}, completion: nil)
I have a priority queue of various actions -- UIImageView translations and the HP bar decreases associated with them. I already programmed a bar widget with CALayer animations, so it should handle itself, but for some reason, even though my loop is sequential, all the animations -- bar animations as well as other actions in the queue -- all happen simultaneously. How do I force sequentiality? Here's code from my viewController .m:
while (![selectedMoves isEmpty])
{
SelectedMove* nextMove = [selectedMoves dequeueMax];
// Move the user to clearly indicate who is moving:
[self animateAttacker:nextMove.user];
[moveReporter setText:report];
[self executeMove:nextMove];
}
executeMove is the wrapper that changes the health bar value to reflect damage.
-(void) executeMove:(SelectedMove*)attack
{
... calculate damage dealt by attack...
// Animate HP bar change on-screen
double percentage = (double)[currentHP intValue] / (double)[currentStats[HP] intValue];
[playerHealthBars[slot] updateBarPercentage:percentage andMaxHP:[currentStats[HP] intValue]];
}
My issue is that all of the healthBar animations, as well as the "animateAttacker" calls, are happening at once on the screen. What command forces one to execute before the other, or forces a screen refresh before moving on?
animateAttacker is the wrapper that translates the appropriate UIImage forward according to nextMove.
The goal is to have each iteration of the loop -- the health bar and the animateAttacker -- execute simultaneously, or sequentially, and to have separate iterations execute in the order of the loop:
:
-(void)animateAttacker:(HonmonBattleState*)attacker
{
UIImageView* attackerImageView = playerImages[index];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1.0];
attackerImageView.transform=CGAffineTransformMakeTranslation(ATTACK_PERTURBATION, -ATTACK_PERTURBATION);
[UIView commitAnimations];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:1.0];
attackerImageView.transform=CGAffineTransformIdentity;
[UIView commitAnimations];
}
Thanks for your help!
PS> I can use CALayer Core Animations or UIView animations. I have done both, and the health bars are internally done using layers.
Block-based UIView animations have completion blocks that you can use to chain animations, see this thread over here.
And you can use completion blocks in CAAnimations with this category on GitHub (it's on CocoaPods if you need).
If you want a global, serial queue for your animations, you should look into having your own NSOperationQueue with a maximum parallel task count of one. This way, all operations you run on it will be delayed until the previous ones have finished.
I have the following block of code to fade out an introView(UIView)
// Hide intro view after 5 seconds
[UIView animateWithDuration: 1.0
delay: 5.0
options: (UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionCurveLinear)
animations: ^{
introView.alpha = 0;
}
completion: ^(BOOL finished) {
[introView removeFromSuperview];
}];
I have a skip button inside the introVew but there is no interaction whatsoever, am I missing something? I have to add this is a Universal app targeting 3.2 and I'm using XCode 4.2
Pretty sure this is impossible pre-4.0:
UIView userInteractionEnabled Docs
During an animation, user interactions are temporarily disabled for
all views involved in the animation, regardless of the value in this
property. You can disable this behavior by specifying the
UIViewAnimationOptionAllowUserInteraction option when configuring the
animation.
There seems little point in targeting 3.2 in an app you haven’t released yet.
Are you setting your button alpha to 0?
If yes here is an interesting thing about animation.
What you see on the screen during the animation is not what the application sees.
The moment you set your alpha to 0, the alpha is 0 for that view, even if you are still seeing it on the screen.
Also, a view that has an alpha lower that 0.05 (don't recall the exact number) won't get touch event.
What you can do is to implement the - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event of that view's superview. or the touchesEnded... as you like.
(Assuming that your not setting it's alpha to 0.)
So you can test for touche that occur where the button is, or just remove that button and let any touch on the screen cancel your animation.
You may also be interested in this post:
Core Animation, unexpected animated position and hitTest values
I found another circumstance which could cause this. I haven't seen this answer anywhere else. It does not deal with alpha at all.
If you use a delay in the call to UIView.animate(), then even if you specify the .allowUserInteraction option, the view does NOT receive touches during the delay period. I have no idea why, but I could help it by moving the code block to another function, and using a performSelector after the same delay seconds, and in the block I run the code without delay.
I had the same problem with a button that I animated with changing the alpha. Cueing off VinceBurn's answer...
What you see on the screen during the animation is not what the application sees. The moment >you set your alpha to 0, the alpha is 0 for that view, even if you are still seeing it on the >screen.
AND view that have an alpha lower that 0.05 (don't recall the exact number) won't get touch >event.
… the simple solution of just making the minimum alpha 0.1 instead of 0.0 worked for me:
[UIView animateWithDuration:0.5
delay:0.0
options:UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse | UIViewAnimationOptionAllowUserInteraction
animations:^{
self.myButton.alpha = 0.1f;
}
completion:^(BOOL finished){
}]
Button registered the touchUpInside all the time with no additional method needed, and there was virtually no difference in appearance from taking the alpha to zero.
This won't work in iOS 3.2 since Blocks are only available in iOS4
you will have to use the standard animation techniques, in a separate thread so that you don't block the interface
[UIView beginAnimations:nil context:nil];
[UIView setAnimationTransition: UIViewAnimationTransitionFlipFromLeft forView:view cache:YES];
[UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];
[UIView setAnimationDuration:1.0];
[view1 setHidden:TRUE];
[UIView commitAnimations];
I'm trying to slow down the animation of the UISlider when changing values.
So far, I've tried the old UIView animation method:
[UIView beginAnimations:#"slider" context:nil];
[UIView setAnimationDuration:5.0];
[self.slider setValue:2 animated:YES];
[UIView commitAnimations];
And the new blocks based method:
[UIView animateWithDuration:5.0
animations:^{
[self.slider setValue:2 animated:YES];
}];
I've tried with and without the animated:YES value set. In all cases, the slider simply animates at the default speed.
Is there another tactic I should be looking at to customize the speed of the animation?
Should I subclass the slider and override anything there?
Check out the OBSlider, a UISlider subclass with variable scrubbing speed (as seen in the iPod app on iOS) by Ole Begemann. I'm not saying it is exactly what you want but you can see how it is implemented since the code is hosted at GitHub. Basically, it subclasses UISlider and overrides the touch tracking methods:
beginTrackingWithTouch:withEvent:
continueTrackingWithTouch:withEvent:
endTrackingWithTouch:withEvent: