I'm running into a weird situation where animating a UIImageView's alpha affects a UIButton which also exists on the same view.
My code:
func handleArrowAnimation(_ arrowImage: UIImageView, _ arrowImageXCenterConstraint: NSLayoutConstraint) {
arrowImageXCenterConstraint.constant = CGFloat(80)
UIView.animate(withDuration: 0.7, delay: 0, options: [.curveEaseInOut, .repeat, .autoreverse], animations: {
arrowImage.alpha = UIApplication.shared.userInterfaceLayoutDirection == .leftToRight ? 1 : 0.2
arrowImage.superview!.layoutIfNeeded()
}) { (completed) in
arrowImageXCenterConstraint.constant = CGFloat(0)
arrowImage.alpha = UIApplication.shared.userInterfaceLayoutDirection == .leftToRight ? 0.2 : 1
arrowImage.superview!.layoutIfNeeded()
}
}
The result:
I found that removing the call to layoutIfNeeded() prevents the UIButton alpha from changing, but of course it also prevents the arrow from moving - so it doesn't help me much.
The UIButton is not a subview of the arrowImage, and they don't share the same parent view (their parents share the same parent, though).
What am i missing here?
Thanks!
So apparently someone else had this issue and the answer is to make sure you start your animations after the view has loaded, for example in the viewDidAppear() method.
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear()
handleArrowAnimation()
}
Here is the link to previous question. There does not appear to be any explanation for the strange behaviour at this time.
Related
I have this simple code:
func tappedButton() {
self.button.alpha = 1.0
UIView.animate(withDuration: 1.0, delay: 4.0, options: .curveLinear, animations: {
self.button.alpha = 0.0
}) { _ in }
}
This function aims at showing a button again for 4 seconds before hiding it (with a 1 second animation). However, while the button is completely visible for these 4 seconds, tapping it doesn't work anymore.
Thanks for your help.
As per the documentation in for the method hittest(_:with:) of UIView https://developer.apple.com/documentation/uikit/uiview/1622469-hittest
This method ignores view objects that are hidden, that have disabled user interactions, or have an alpha level less than 0.01. This method does not take the view’s content into account when determining a hit. Thus, a view can still be returned even if the specified point is in a transparent portion of that view’s content.
This means that any view, particularly a button, with alpha 0.0 would not be touched.
However, the problem here is that the button is still visible, at least for you. This odd behavior occurs because the actual alpha value of the button is already setted to 0.0 when the animations starts. Animations work by changing the visual hierachy and transition the difference with the parameters you give to the function. In your case, you have two states: a view with a visible button visible and another view without the button. Only the visual part is animated but the corresponding values are already setted. A solution would be:
func tappedButton() {
self.button.alpha = 1.0
UIView.animate(withDuration: 1.0, delay: 4.0, options: .curveLinear, animations: { [weak self] in
self?.button.alpha = 0.01
}) { [weak self] _ in self?.button.alpha = 0.0 }
}
EDIT: This solution seems like a hack but works. I use this approach because the completion handler is always called with a true value.
func tapped() {
let duration = 1.0
let delay = 2.0
let delayDuration = delay + duration
UIView.animate(withDuration: duration, delay: delay, options: [.curveLinear, .allowUserInteraction], animations: { [weak self] in
self?.saveButton.alpha = 0.1
})
DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + delayDuration, execute: { [weak self] in
self?.saveButton.alpha = 0.0
})
}
You need to use allUserInteraction in the options and also check for touches. The animation is added immediately and although you see the button to the system it is already hidden. What does this mean? It means you are watching a movie. But at least with userInteraction enabled you can check for touch events. This is great but how do we know the button is really showing or not? Well you have to use two different checks most likely. One that checks the true UIView alpha of the button and one check that checks the opacity on the presentation layer. I have never fully looked at the link between UIView animations and Core Animation except that I think UIView animations are a wrapper for Core Animations. UIView animations definitely update the view model immediately. So an alpha animation is most likely interpreted into an opacity animation on the layer. Armed with this we can check the opacity of the presentation layer on touches and see that the button is being clicked even if the view model thinks the alpha is 0. This check on the presentation layer will work as long as the opacity is above 0. So here you go.
import UIKit
class ViewController: UIViewController {
lazy var testButton : UIButton = {
let v = UIButton(frame: CGRect(x: 20, y: 50, width: self.view.bounds.width - 40, height: 50))
v.backgroundColor = UIColor.blue
v.addTarget(self, action: #selector(buttonClicked), for: .touchUpInside)
return v
}()
override func viewDidLoad() {
super.viewDidLoad()
self.view.addSubview(testButton)
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
UIView.animate(withDuration: 1.0, delay: 4.0, options: .allowUserInteraction, animations: {
self.testButton.alpha = 0
}, completion: nil)
//test the layer
//test the layer for opacity
if let presentation = testButton.layer.presentation()?.animation(forKey: "opacity"){
print("the animation is already added so normal clicks won't work")
}
}
#objc func buttonClicked(){
print("clicked")
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
super.touchesBegan(touches, with: event)
if let touch = touches.first{
let location = touch.location(in: self.view)
if self.testButton.frame.contains(location){
//but what you might not know is the animation is probably already running
//and so the check above misses this
if let buttonPres = testButton.layer.presentation(),
let _ = buttonPres.animation(forKey: "opacity"),
let opacity = buttonPres.value(forKey: "opacity") as? CGFloat{
if opacity > 0{
buttonClicked()
}
}
}
}
}
}
How do you animate a color change in table view cells when a user taps the a table view's edit button?
When the edit button is tapped, Apple's animation shifts the contents of all the cells right to display a delete or insert button in each cell. I'd like to add my own animations that occur simultaneously with Apple's. I've managed to animate the cell layout but not color changes.
This is what I'm doing:
override func willTransition(to state: UITableViewCellStateMask) {
super.willTransition(to: state)
let willEdit = state.contains(.showingEditControlMask)
toDateDaysLayoutConstraint.constant = willEdit ? 5.0 : 25.0
daysNightsLayoutConstraint.constant = willEdit ? 5.0 : 10.0
toDateTextView.textColor = willEdit ? UIColor.red : UIColor.darkText
daysLabel.backgroundColor = willEdit ? UIColor.cyan : UIColor.clear
}
To be clear, the above layoutConstraint changes animate properly, but the colors change instantaneously without animation.
I've also tried to animate the color using UIView block animations as follows:
UIView.animate(withDuration: 5.0) {
self.toDateTextView.textColor = willEdit ? UIColor.red : UIColor.darkText
self.daysLabel.backgroundColor = willEdit ? UIColor.cyan : UIColor.clear
}
But, I can never get the color to animate. I've tried putting the above code in willTransition(to state:), setEditing(_ editing: animated:), even layoutSubviews(). I've also tried it in the table controller methods. But, nothing works.
UPDATE
By now, I've also tried wrapping everything between CATransaction.begin() and CATransaction.commit(), also using only layer animations, and even putting the commit in didTransition after the call to super. Nothing works.
I'm wondering, is it possible to do any animation simultaneously with Apple's that's not a layout animation?
From what I understand you can only animate "animatable" properties of a UIView (see this list). textColor isn't in it. I've used UIView.transition(with:duration:options:animations) in place and the text color is "animated" properly:
override func willTransition(to state: UITableViewCellStateMask) {
super.willTransition(to: state)
UIView.transition(with: textLabel!, duration: 5.0, options: .transitionCrossDissolve, animations: {
self.textLabel?.textColor = state.rawValue == 1 ? UIColor.red : UIColor.black
})
}
EDIT 1
Following your comment, I've managed to reproduce the issue. I fixed it for the UILabel by overriding didTransition(to:) instead of willTransition(to:). So we first wait for the views to be resized (because of the appearing delete button) and then we animate. However, this does not work very well for the UITextView, unless you make sure it has a fixed size.
class TableViewCell: UITableViewCell {
#IBOutlet weak var textView: UITextView!
#IBOutlet weak var label: UILabel!
override func didTransition(to state: UITableViewCellStateMask) {
super.didTransition(to: state)
UIView.transition(with: textView, duration: 3, options: .transitionCrossDissolve, animations: {
self.textView.textColor = state.rawValue == 1 ? UIColor.red : UIColor.black
})
UIView.transition(with: label, duration: 3, options: .transitionCrossDissolve, animations: {
self.label.backgroundColor = state.rawValue == 1 ? UIColor.red : UIColor.white
})
}
}
EDIT 2
If you need your text view to be resizable then execute the animation asynchronously:
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
UIView.transition(with: self.textView, duration: 3, options: .transitionCrossDissolve, animations: {
self.textView.textColor = state.rawValue == 1 ? UIColor.red : UIColor.black
})
}
By the way, I also tried to subclass UITextView and override layoutSubviews but it did not work...
I have created an animated label with UIView that is glitches when switching between View Controllers within a Tab Bar.
I've attached a GIF of what's occurring and a picture of my storyboard layout below, respectively.
Glitching Label
Storyboard Setup
Caveat: I realize that my code is not-so-elegant, to put it nicely, but does anyone know why this is happening or how I can
A) stop this from happening?
and/or
B) fix it?
Is it my code (probably), a bug within the simulator (not likely), or am I approaching the animation incorrectly?
I'm using this
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(true)
self.updateGSLabel(textArray: ["Game Mode", "Play"], index : 0)
}
func updateGSLabel(textArray : [String], index : Int){
UIView.animate(withDuration: 1.25, animations: {
self.gameModeLabel.alpha = 0.0
}) { (success) in
self.gameModeLabel.text = textArray[index]
UIView.animate(withDuration: 1.25, animations: {
self.gameModeLabel.alpha = 1.0
}) { (success) in
var newIndex = index
if(newIndex == textArray.count - 1) {
newIndex = -1
}
self.updateGSLabel(textArray: textArray, index : newIndex + 1)
}
}
}
EDIT
This may have something to do with closure parameters, but I don't know. If someone could elaborate better that'd be appreciated.
I tried to link to a page about it, but apparently I need at least 10 rep to post more than 2 links, which I think I've already done so I don't know how that's possible.
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.
I am trying to get a view to animate from the centre of the screen, to leave the screen after 1 second when the view loads.
The problem I am having is that after a millisecond of the view being in the original (correct) position upon loading, it then snaps to the new position and animates back to the original position.
I have the following code in viewDidLoad
override func viewDidAppear(animated: Bool) {
UIView.animateWithDuration(0.7, delay: 1, options: .CurveEaseOut, animations: {
var loadingViewFrame = self.loadingView.frame
loadingViewFrame.origin.y += 600
self.loadingView.frame = loadingViewFrame
}, completion: { finished in
print("moved")
})
}
I have tried putting this code in a button action and it works fine, so is there some other method I should be using when animating on viewWillAppear or is there something else I have missed?
I have removed all autolayout constraints because I read that they may cause some problems.
I also have other code in viewDidAppear as well as viewWillAppear and viewDidLoad which I could show here if you think it is useful, but I have commented out all of this code to leave with only the basic code and the same error is still occurring.
Thanks a lot for your help.
Edit 1
I have moved the code to viewDidLayoutSubviews and have used dispatch_once to ensure it is only done once. The image still animates from the new position to the original position, but now the image is not located in the original position for a millisecond upon loading.
This is the code I have added
var token: dispatch_once_t = 0
override func viewDidLayoutSubviews() {
dispatch_once(&token) {
UIView.animateWithDuration(0.7, delay: 1, options: .CurveEaseOut, animations: {
var loadingViewFrame = self.loadingView.frame
loadingViewFrame.origin.x += 600
self.loadingView.frame = loadingViewFrame
}, completion: { finished in
print("moved")
})
}
}
First off, you need to call super.viewDidAppear(animated) when you override viewDidAppear: in your view controller subclass.
Unfortunately, it seems to work just fine for me with this view controller so there must be something else going on...
class ViewController: UITableViewController {
var loadingView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
loadingView = UIView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))
loadingView.backgroundColor = UIColor.redColor()
loadingView.center = view.center
view.addSubview(loadingView)
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
UIView.animateWithDuration(0.7, delay: 1, options: .CurveEaseOut, animations: {
var loadingViewFrame = self.loadingView.frame
loadingViewFrame.origin.y += 600
self.loadingView.frame = loadingViewFrame
}, completion: nil)
}
}
Your issue is most-likely because layoutSubviews may be called after viewDidAppear: (I believe this is different for iOS 8 vs iOS 9) so the changes you made get overridden almost immediately. You can confirm this by overriding viewDidLayoutSubviews in your UIViewController subclass and breakpointing viewDidLoad, viewWillAppear:, viewDidAppear:, and viewDidLayoutSubviews to see what order they happen in.
One thing you can do to achieve a similar effect is use a dispatch_once block with a once_token that is a property of your class to execute the animation in viewDidLayoutSubviews. This will insure that your animation is executed once per instance of your class after the initial view layout has occurred. This might be what you're looking for.
If you could provide more of your view controller code or a github link I may be able to give you a better, less potentially hacky, answer about what is going on.