Swift ios cant get animation to be infinite - ios

I have a animation that I want to be infinite
var rotateRock: Bool = true
func rotateRock() {
UIView.animate(withDuration: 2.7, delay: 2.7, options: [UIViewAnimationOptions.repeat, UIViewAnimationOptions.curveLinear], animations:
{
self.rockImg.transform.ty += 155
if self.rotateRock {
self.rotateRock = false
self.rockImg.transform = CGAffineTransform(rotationAngle: (180.0 * CGFloat(M_PI)) / 180.0)
} else {
self.rotateRock = true
self.rockImg.transform = CGAffineTransform(rotationAngle: 0)
}
},completion: nil)
}
Then I call rotateRock() inside viewDidLoad() this works, the animation never stops which is what I want.
If I now enter another VC that is presented modally then exit it so I end up in my first VC the animation is still running which I want.
But if I change VC by clicking on another tab in my tab bar and then go back the animation has stopped. Is there any way to check if the animation has stopped so that I can restart it?

You could override viewDidAppear() and call rotateRock there. That should work.
Edit:
What Matt says below is true, viewDidAppear would work but maybe it would be better viewWillAppear to make sure you don't see it before starting.

Related

UIViewPropertyAnimator repeat

I've taken a look at the answers in the following StackOverflow question but none seem to work for me: on the execution of the completion block, instead of performing the animation again, the program spews out "complete" ad infinitum without animating the view at all.
How can I repeat animation (using UIViewPropertyAnimator) certain number of times?
This is my AnimatorFactory class:
class AnimatorFactory {
#discardableResult
static func rotateRepeat(view: UIView) -> UIViewPropertyAnimator {
let rotate = UIViewPropertyAnimator.runningPropertyAnimator(withDuration: 1.0, delay: 0.0, options: [.curveLinear], animations: {
view.transform = CGAffineTransform(rotationAngle: .pi)
}, completion: { _ in
print("complete")
self.rotateRepeat(view: view)
})
return rotate
}
}
It is called as you'd expect with AnimatorFactory.rotateRepeat(view: <someView>)
However, the problem as mentioned above occurs. What I'd expect is that the view would rotate repeatedly until some time that I decide to change or stop it; this is exactly the reason that I have chosen to use UIViewPropertyAnimator instead of UIView.animate(withDuration:animations).
What's the best way then to create interactive, repeatable UIView animations? Much appreciated.
Your code is working fine. The trouble is that your animation does nothing after the first time. You say:
view.transform = CGAffineTransform(rotationAngle: .pi)
The first time, we change the rotation from 0 to pi. That is a change, so there is animation. But after that we just keep saying “stay at pi” over and over. We are at pi and you say to stay there, so there is no change to animate.
What you want each animation to do is add pi, not be pi.
As #matt suggested, I was merely setting the rotation of the view to .pi over and over. So in the completion block I have now set the transform to .identity before kicking the animation off again.
class AnimatorFactory {
#discardableResult
static func rotateRepeat(view: UIView) -> UIViewPropertyAnimator {
let rotate = UIViewPropertyAnimator(duration: 1.0, curve: .linear)
rotate.addAnimations {
view.transform = CGAffineTransform(rotationAngle: .pi)
}
rotate.addCompletion{ _ in
view.transform = .identity
self.rotateRepeat(view: view)
}
rotate.startAnimation()
return rotate
}
}

How to prevent from stacking views in a custom segue?

I coded a custom segue emulating a "Push Left". I takes screenshots of the 2 views, animates them from right to left, then present the destination view and remove the overlaying screenshots. I'm afraid that this ultimately results in stacking views on top of one another, which should be avoided in this case. I can't figure out how to properly dismiss the underlaying view once the animation is completed. I tried to use navigationController?.pushViewController instead of present but my attempts were not successful. How could I solve this issue ?
My custom segue :
class SeguePushLeft: UIStoryboardSegue
{
override func perform()
{
self.source.view.isUserInteractionEnabled = false
self.destination.view.isUserInteractionEnabled = false
let slideViewOut = UIImageView(image: source.view.capture()!)
let slideViewIn = UIImageView(image: destination.view.capture()!)
let screenWidth = source.view.frame.size.width
self.source.view.addSubview(slideViewIn)
self.source.view.addSubview(slideViewOut)
slideViewIn.transform = CGAffineTransform(translationX: screenWidth, y: 0)
UIView.animate(withDuration: 0.4,
delay: 0.0,
usingSpringWithDamping: 1,
initialSpringVelocity: 0,
options: UIViewAnimationOptions.curveEaseOut,
animations: {
slideViewIn.transform = CGAffineTransform.identity
slideViewOut.transform = CGAffineTransform(translationX: -screenWidth, y: 0)
}, completion: { finished in
DispatchQueue.main.async{
(self.source as UIViewController).present((self.destination as UIViewController), animated: false, completion: {
self.source.view.isUserInteractionEnabled = true
self.destination.view.isUserInteractionEnabled = true
slideViewIn.removeFromSuperview()
slideViewOut.removeFromSuperview()
})
}
})
}
}
[Please forgive my previous too-hasty answer. I'm entering another rather than editing the first, because of all the comments that now blot the first.]
The problem is simple: you're doing this wrong. What you wish to do is a present transition, but with a custom animation. That's perfectly viable, and you can certainly do it with a custom segue, but the way you're doing it is not how you do that. You do it with a custom transition animation. There is a fixed way of implementing that, and it isn't how you're going about things. You need to read up on how to write a custom transition animation for a presentation transition and you'll be all set.

UIView.animateWithDuration Not Animating Swift (again)

Note: I’ve already checked the following stack overflow issues:
27907570, 32229252, 26118141, 31604300
All I am trying to do is fade animate in a view (by alpha) when called by an IBAction attached to a button. Then reverse when a button on the view is hit.
My wrinkle may be that I'm using a secondary view that is on the ViewDock in the storyboard View. The view is added to the subview at the time of viewDidLoad where the frame/bounds are set to the same as the superview (for a full layover)
The reason this is done as an overlay view since it is a tutorial indicator.
The result (like many others who've listed this problem) is that the view (and contained controls) simply appears instantly and disappears as instantly. No fade.
I have tried animationWithDuration with delay, with and without completion, with transition, and even started with the old UIView.beginAnimations.
Nothing is working. Suggestions warmly welcomed.
The code is about as straight forward as I can make it:
Edit: Expanded the code to everything relevant
Edit2: TL;DR Everything works with the exception of UIViewAnimateWithDuration which seems to ignore the block and duration and just run the code inline as an immediate UI change. Solving this gets the bounty
#IBOutlet var infoDetailView: UIView! // Connected to the view in the SceneDock
override func viewDidLoad() {
super.viewDidLoad()
// Cut other vDL code that isn't relevant
setupInfoView()
}
func setupInfoView() {
infoDetailView.alpha = 0.0
view.addSubview(infoDetailView)
updateInfoViewRect(infoDetailView.superview!.bounds.size)
}
func updateInfoViewRect(size:CGSize) {
let viewRect = CGRect(origin: CGPointZero, size: size)
infoDetailView.frame = viewRect
infoDetailView.bounds = viewRect
infoDetailView.layoutIfNeeded()
infoDetailView.setNeedsDisplay()
}
override func viewWillTransitionToSize(size: CGSize, withTransitionCoordinator coordinator: UIViewControllerTransitionCoordinator) {
super.viewWillTransitionToSize(size, withTransitionCoordinator: coordinator)
updateInfoViewRect(size)
}
func hideInfoView() {
AFLog.enter(thisClass)
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.0
},
completion:
{ (finished) in
return true
}
)
AFLog.exit(thisClass)
}
func showInfoView() {
AFLog.enter(thisClass)
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.75
},
completion:
{ (finished) in
return true
}
)
AFLog.exit(thisClass)
}
// MARK: - IBActions
#IBAction func openInfoView(sender: UIButton) {
showInfoView()
}
#IBAction func closeInfoView(sender: UIButton) {
hideInfoView()
}
Please note, I started with the following:
func showInfoView() {
UIView.animateWithDuration(2.0, animations: { () -> Void in
self.infoDetailView.alpha = 0.75
})
}
func hideInfoView() {
UIView.animateWithDuration(2.0, animations: { () -> Void in
self.infoDetailView.alpha = 0.00
})
}
If you infoDetailView is under auto layout constraints you need to call layoutIfNeeded on the parent view inside animateWithDuration:
func showInfoView() {
self.view.layoutIfNeeded() // call it also here to finish pending layout operations
UIView.animate(withDuration: 2.0, animations: {
self.infoDetailView.alpha = 0.75
self.view.layoutIfNeeded()
})
}
Theoretically this should not be needed if you just change the .alpha value, but maybe this could be the problem in this case.
There are several strange things I can see,
first, remove:
infoDetailView.layoutIfNeeded()
infoDetailView.setNeedsDisplay()
Usually you don't need to call those methods manually unless you know exactly what you are doing.
Also, when you are changing the size:
infoDetailView.frame = viewRect
infoDetailView.bounds = viewRect
You never need to set both bounds and frame. Just set frame.
Also, you should probably make sure that the view actually doesn't ignore the frame by setting:
infoDetailView.translatesAutoresizingMaskIntoConstraints = true
Instead of resetting the frame, just set autoresize mask:
infoDetailView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
Resulting in:
override func viewDidLoad() {
super.viewDidLoad()
// Cut other vDL code that isn't relevant
setupInfoView()
}
func setupInfoView() {
infoDetailView.alpha = 0.0
infoDetailView.translatesAutoresizingMaskIntoConstraints = true
infoDetailView.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
infoDetailView.frame = view.bounds
view.addSubview(infoDetailView)
}
func hideInfoView() {
...
}
I think this should actually help because immediate animations are often connected to size problems.
If the problem persists, you should check whether the infoDetailView in your animation is the same object as the infoDetailView you are adding to the controller.
For others looking to start an animation immediately when a view loads...
The animation won't work if you call UIView.animate(...) inside viewDidLoad. Instead it must be called from the viewDidAppear function.
override func viewDidAppear(_ animated: Bool) {
UIView.animate(withDuration: 3) {
self.otherView.frame.origin.x += 500
}
}
If the animation does not seem to execute then consider examining the state of each of your views, before you enter the animation block. For example, if the alpha is already set to 0.4 then the animation that adjusts your view alpha, will complete almost instantly, with no apparent effect.
Consider using a keyframe animation instead. This is what a shake animation in objective c looks like.
+(CAKeyframeAnimation*)shakeAnimation {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:#"transform"];
animation.values = #[[NSValue valueWithCATransform3D:CATransform3DMakeTranslation(-10.0, 0.0, 0.0)],
[NSValue valueWithCATransform3D:CATransform3DMakeTranslation(10.0, 0.0, 0.0)]];
animation.autoreverses = YES;
animation.repeatCount = 2;
animation.duration = 0.07;
return animation;
}
Here is a post that shows you how to adjust alpha with keyframes https://stackoverflow.com/a/18658081/1951992
Make sure infoDetailView's opaque is false.
https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIView_Class/#//apple_ref/occ/instp/UIView/opaque
This property provides a hint to the drawing system as to how it should treat the view. If set to true, the drawing system treats the view as fully opaque, which allows the drawing system to optimize some drawing operations and improve performance. If set to false, the drawing system composites the view normally with other content. The default value of this property is true.
Try Below code. Just play with alpha and duration time to perfect it.
Hide func
func hideInfoView() {
AFLog.enter(thisClass)
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.8
},
completion:
{ (finished) in
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.4
},
completion:
{ (finished) in
self.infoDetailView.alpha = 0.0
}
)
}
)
AFLog.exit(thisClass)
}
Show func
func showInfoView() {
AFLog.enter(thisClass)
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.3
},
completion:
{ (finished) in
UIView.animateWithDuration(
2.0,
animations:
{
self.infoDetailView.alpha = 0.7
},
completion:
{ (finished) in
self.infoDetailView.alpha = 1.0
}
)
}
)
AFLog.exit(thisClass)
}
I've replicated your code and it work well, it's all ok.
Probably you must control constraints, IBOutlet and IBActions connections. Try to isolate this code into a new project if it's necessary.
Update: my code
and my storyboard and project folder photo:
Every object (view and buttons) are with default settings.
I've commented all AFLog lines (probably it's only any more "verbose mode" to help you) , the rest of your code is ok and it do what do you aspected from it, if you press open button the view fade in, and when you tap close button the view fade out.
PS Not relevant but i'm using xCode 7.3 , a new swift 2.2 project.
Use this code:
Swift 2
UIView.animateWithDuration(0.3, animations: { () -> Void in
self.infoDetailView.alpha = 0.0
})
Swift 3, 4, 5
UIView.animate(withDuration: 0.3, animations: { () -> Void in
self.infoDetailView.alpha = 0.0
})
Have you tried changing your showInfoView() to something more like toggleInfoView?
func toggleInfoView() {
let alpha = CGFloat(infoDetailView.alpha == 0 ? 1 : 0)
infoDetailView.alpha = alpha //this is where the toggle happens
}
It says that if your view's alpha is 0, then change it to 1. Else, make it 0.
If you need that to happen in an animation, try
#IBAction func openInfoView(sender: UIButton) {
UIView.animate(withDuration: 2.0, animations: {
self.toggleInfoView() //fade in/out infoDetailView when animating
})
}
You'll still want to keep that infoDetailView.alpha = 0.0 where you have it, coming from the viewDidLoad.
For UILabel component try to changes layer's background color instead.
Try this (Tested on Swift 4):
UIView.animate(withDuration: 0.2, animations: {
self.dateLabel.layer.backgroundColor = UIColor.red.cgColor;
})
Had a similar issue with animation not being performed.
Changed the function call use perform(aSelector: Selector, with: Any?, afterDelay: TimeInterval) in the form of perform(#selector(functionThatDoesAnimationOfAlphaValue), with: nil, afterDelay: 0) and it worked. Even with a TimeInterval set to 0.
In case someone else comes here wondering for a solution.

UIView.animateWithDuration completes too early when changing view with Tab Bar Controller

I am making a progress bar by increasing the with of a simple image:
let progressBar = createProgressBar(width: self.view.frame.width, height: 60.0)
let progressBarView = UIImageView(image: progressBar)
progressBarView.frame = CGRect(x: 0, y: 140, width: 0, height: 60)
UIView.animateWithDuration(60.0, delay: 0.0, options: [], animations: {
progressBarView.frame.size.width = self.backgroundView.frame.size.width
}, completion: {_ in
print("progress completed")
}
)
This works as expected, but I am having problems when changing views using a TabBarController. When I change view, I would like the progress bar to continue animating in the background, such that I can go back to this view to check on progress, but instead it does end immediately when I change views, and the completion block is called.
Why does this happen, and how to fix it?
When you tap another tabBar item, the viewController that is performing animation will be in a state of viewDidDisappear and the animation will be removed.
Actually, it is not recommended to perform any animation when the viewController is not presented in the front of the screen.
To continue the interrupted animation progress, you have to maintain the current states of the animation and restore them when the tabBar item switched back.
For example, you may hold some instance variables to keep the duration, progress, beginWidth and endWidth of the animation. And you can restore the animation in viewDidAppear:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
// `self.duration` is the total duration of the animation. In your case, it's 60s.
// `self.progress` is the time that had been consumed. Its initial value is 0s.
// `self.beginWidth` is the inital width of self.progressBarView.
// `self.endWidth`, in your case, is `self.backgroundView.frame.size.width`.
if self.progress < self.duration {
UIView.animateWithDuration(self.duration - self.progress, delay: 0, options: [.CurveLinear], animations: {
self.progressBarView.frame.size.width = CGFloat(self.endWidth)
self.beginTime = NSDate() // `self.beginTime` is used to track the actual animation duration before it interrupted.
}, completion: { finished in
if (!finished) {
let now = NSDate()
self.progress += now.timeIntervalSinceDate(self.beginTime!)
self.progressBarView.frame.size.width = CGFloat(self.beginWidth + self.progress/self.duration * (self.endWidth - self.beginWidth))
} else {
print("progress completed")
}
}
)
}
}

UIView.animateWithDuration in Swift - iOS7 issue

I am trying clear the data in a UITableView with some quick animation, I am using the below code, which works fine in iOS8.
However when I run it on iOS7 it only runs the block after completion , but not the first animation code (fade out), so the animation looks very bad, the tableview disappears suddenly and returns back with animation.
any idea what is wrong here? what is the problem with it in iOS7?
UIView.animateWithDuration (0.5, animations: {
self.tableView.transform = CGAffineTransformMakeScale(0.2, 0.2)
self.tableView.alpha = 0
}, completion: { (value: Bool) in
UIView.animateWithDuration (0.5, animations: {
self.tableView.reloadData()
self.tableView.transform = CGAffineTransformMakeScale(1.0, 1.0)
self.tableView.alpha = 1
println ("animation done")
})
})
Try removing UIView.animateWithDuration (0.5, animations: { block inside completion block and check

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