I'm trying to rotate the background colour endlessly between two different gradients, but the actual transition isn't lasting as long as expected (it lasts for less than a second and there's no delay between each transition).
var backgroundColours = [CAGradientLayer()]
var backgroundLoop = 0
override func viewDidLoad() {
super.viewDidLoad()
backgroundColours = [Colors.init().one, Colors.init().two] // These are two CAGradientLayers but I haven't included their code
backgroundLoop = 0
self.animateBackgroundColour()
}
func animateBackgroundColour () {
backgroundLoop = (backgroundLoop + 1) % (backgroundColours.count)
UIView.animate(withDuration: 2.0, delay: 2.0, options: .curveLinear, animations: {
self.view.backgroundColor = UIColor.clear
let backgroundLayer = self.backgroundColours[self.backgroundLoop]
backgroundLayer.frame = self.view.frame
self.view.layer.insertSublayer(backgroundLayer, at: 0)
}, completion: { (Bool) -> Void in
self.animateBackgroundColour()
})
This is all inside the ViewController Class
UIView.animate animates only about five specialized view properties. You are not animating any of those properties. What you want is layer animation (e.g. CABasicAnimation).
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()
}
}
}
}
}
}
I've been testing a random animation for views inside a view controller. It seems to work well when executed once. However, when I place the code in a while-loop, the application crashes; CPU usage accelerates to 100%. This is due to the constant generation of a random coordinate. What would be the best way to format this code to create a looped random animation, without crashing the app?
func randomAnimationForPostPackets () {
func completionMethodX () -> CGFloat {
let randomCoordinatesXInt: UInt32 = arc4random_uniform(300)
let randCoordsX = CGFloat(randomCoordinatesXInt)
return randCoordsX
}
func completionMethodY () -> CGFloat {
let randomCoordinatesYInt: UInt32 = arc4random_uniform(300)
let randCoordsY = CGFloat(randomCoordinatesYInt)
return randCoordsY
}
UIView.animateWithDuration(5, animations: {
self.postPacketView.center.x = completionMethodX()
self.postPacketView.center.y = completionMethodY()
},completion: {(finished:Bool) in
completionMethodX()
completionMethodY()
})
}
This method is implemented in the viewDidLoad method in the view controller as so:
override func viewDidLoad() {
super.viewDidLoad()
UIApplication.sharedApplication().statusBarStyle = .LightContent
webBackground()
createBlurEffectView()
let randomPositionX : UInt32 = arc4random_uniform(300)
let randomPositionY : UInt32 = arc4random_uniform(300)
let randomPositionCGX : CGFloat = CGFloat(randomPositionX)
let randomPositionCGY : CGFloat = CGFloat(randomPositionY)
postPacketView.frame = CGRectMake(randomPositionCGX, randomPositionCGY, 75, 75)
self.view.addSubview(postPacketView)
mainSegueButtonSetup()
**randomAnimationForPostPackets()**
userViewSetup()
self.definesPresentationContext = true
// Do any additional setup after loading the view.
}
Any assistance would be appreciated.
in your UIView.animateWithDuration method, you need to have arguments for options:. In this case I believe you would use .Repeat and/or Autoreverse for your to get your desired effect.
See Apple documentation for UIViewAnimationOptions for a complete list of options you can use with your animation.
Edit your code to perform nil on completion: rather than the two method calls you've listed.
UIView.animateWithDuration(5, options: [.Repeat, .Autoreverse], animations: {
self.postPacketView.center.x = completionMethodX()
self.postPacketView.center.y = completionMethodY()
}, completion: nil
})
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 a beginner in swift. I am building a single view tip calculator app and i only want some animation to happen when the app loads for the first time. And not happen every time i edit something.
Here is my code:
I am hiding the container outside the view when the app loads
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
billView.center.y -= (billView.frame.height)/2
}
And animating it to move down
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
UIView.animateWithDuration(0.8, delay: 0.0,
options: [.CurveEaseOut], animations: {
self.billView.center.y = 210 }, completion: nil)
print(billView.center.y)
}
This works fine when the app loads. Unfortunately this animation keeps happening again and again anytime I interact with the app.
Like this animation happens when this function is called (which is when any information is entered on the text field or the slider is moved)
let billAmount = NSString(string: billField.text!).doubleValue
var tipPercentages = [0.15, 0.18, 0.22]
let tipPercentage = tipPercentages[segTipControl.selectedSegmentIndex]
let percentLabel = round(tipPercentage * 100)
selectedbillPercentageLabel.text = "+\(percentLabel)%"
let tipAmount = billAmount * tipPercentage
let totalAmount = billAmount + tipAmount
let roundedTotalAmount = round(totalAmount * 100)/100
totalLabel.text = "$\(roundedTotalAmount)"
let splitSelected = Double(splitValueSlider.value)
let intsplitSelected = Int(splitSelected)
splitLabel.text = "\(intsplitSelected)"
let splitDollarAmount = roundedTotalAmount/splitSelected
let roundedSplitDollarAmount = round(splitDollarAmount * 100)/100
splitAmount.text = "$\(roundedSplitDollarAmount)"
Is there a way to avoid calling the method viewDidLayoutSubviews() when any data is entered in the app.
animated gif
Rather than avoiding calling viewDidLayourSubviews, you could add a simple boolean flip to show your animation only once. Add a boolean property that you initialize to false; show animation on condition of this property being false, and flip the boolean after the animation has been shown.
var animationHasBeenShown = false // class property
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if !animationHasBeenShown {
UIView.animateWithDuration(0.8, delay: 0.0,
options: [.CurveEaseOut], animations: {
self.billView.center.y = 210 }, completion: nil)
print(billView.center.y)
animationHasBeenShown = true
}
}
Alternatively, consider placing your animation in another context; does it really need to be in viewDidLayoutSubviews() (depends on the context of your app, but possibly rather in viewDidAppear()?)
Im trying to make a small game. And there is some problem with the animation. Im new to Swift. So lets take a look. I create a UIImageView picture and want to do animation of this picture appear in a different places on a screen. I believe that the algorithm will look like this:
Infinite loop{
1-GetRandomPlace
2-change opacity from 0 to 1 and back(with smooth transition)
}
Looks simple, but I can't understand how to do it correctly in Xcode.
Here is my test code but it looks useless
Thank you for help and sorry if there was already this question, I can't find it.
class ViewController: UIViewController {
#IBOutlet weak var BackgroundMainMenu:UIImageView!
#IBOutlet weak var AnimationinMenu: UIImageView!
override func viewDidLoad() {
super.viewDidLoad()
// MoveBackgroundObject(AnimationinMenu)
// AnimationBackgroundDots(AnimationinMenu, delay: 0.0)
// self.AnimationinMenu.alpha = 0
//
// UIImageView.animateWithDuration(3.0,
// delay: 0.0,
// options: UIViewAnimationOptions([.Repeat, .CurveEaseInOut]),
// animations: {
// self.MoveBackgroundObject(self.AnimationinMenu)
// self.AnimationinMenu.alpha = 1
// self.AnimationinMenu.alpha = 0
// },
// completion: nil)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewWillAppear(animated: Bool) {
AnimationBackgroundDots(AnimationinMenu, delay: 0.0)
}
func ChangeOpacityto1(element: UIImageView){
element.alpha = 0
UIView.animateWithDuration(3.0) {
element.alpha = 1
}
}
func ChangeOpacityto0(element: UIImageView){
element.alpha = 1
UIView.animateWithDuration(3.0){
element.alpha = 0
}
}
func AnimationBackgroundDots(element: UIImageView, delay: Double){
element.alpha = 0
var z = 0
while (z<4){
MoveBackgroundObject(AnimationinMenu)
UIImageView.animateWithDuration(3.0,
animations: {
element.alpha = 0
element.alpha = 1
element.alpha = 0
},
completion: nil)
z++
}
}
func MoveBackgroundObject(element: UIImageView) {
// Find the button's width and height
let elementWidth = element.frame.width
let elementHeight = element.frame.height
// Find the width and height of the enclosing view
let viewWidth = BackgroundMainMenu.superview!.bounds.width
let viewHeight = BackgroundMainMenu.superview!.bounds.height
// Compute width and height of the area to contain the button's center
let xwidth = viewWidth - elementWidth
let yheight = viewHeight - elementHeight
// Generate a random x and y offset
let xoffset = CGFloat(arc4random_uniform(UInt32(xwidth)))
let yoffset = CGFloat(arc4random_uniform(UInt32(yheight)))
// Offset the button's center by the random offsets.
element.center.x = xoffset + elementWidth / 2
element.center.y = yoffset + elementHeight / 2
}
}
The problem is in AnimationBackgroundDots.
You are immediately creating 4 animations on the same view but only one can run at a time. What you need to do is wait until one animation is finished (fade in or fade out) before starting a new one.
Also, the animations closure is for setting the state you want your view to animate to. It looks at how your view is at the start, runs animations, then looks at the view again and figures out how to animate between the two. In your case, the alpha of the UIImageView starts at 0, then when animations runs, the alpha ends up being 0 so nothing would animate. You can't create all the steps an animation should take that way.
Want you need to do it move your view and start the fade in animation. The completion closure of fading in should start the fade out animation. The completion closure of the fading out should then start the process all over again. It could look something like this.
func AnimationBackgroundDots(element: UIImageView, times: Int) {
guard times > 0 else {
return
}
MoveBackgroundObject(element)
element.alpha = 1
// Fade in
UIView.animateWithDuration(3.0, animations: {
element.alpha = 1
}, completion: { finished in
// Fade Out
UIView.animateWithDuration(3.0, animations: {
element.alpha = 0
}, completion: { finished in
// Start over again
self.AnimationBackgroundDots(element, times: times-1)
})
})
}
You called also look at using keyframe animations but this case is simple enough that theres no benefit using them.
Also as a side note. The function naming convention in swift is to start with a lowercase letter, so AnimationBackgroundDots should be animationBackgroundDots.