I can get the colour on a point of a view as proposed in https://stackoverflow.com/a/25956283/99214 by #jack-song . However when I animate the view
let scaledAndTranslatedTransform = imageViewShape.transform.translatedBy(x: -imageViewShape.bounds.width * 2 - 200, y: 0.0)
UIView.animate(withDuration: TimeInterval(duration), animations: {
self.imageViewShape.transform = scaledAndTranslatedTransform
}, completion: { _ in
})
I cannot get the colour of the point as the view moves.
How can I get the point when the view is moving?
Use presentationLayer property of view's layer because if we see in MVC pattern you will have model before animation and after animation as core animation classes are model in MVC pattern and so if you want to get the values in between animation use presentation layer
Related
When presenting a view controller using a custom animation, none of Apple's documentation or example code mentions or includes constraints, beyond the following:
// Always add the "to" view to the container.
// And it doesn't hurt to set its start frame.
[containerView addSubview:toView];
toView.frame = toViewStartFrame;
The problem is that the double-height status bar is not recognized by custom-presented view controllers (view controllers that use non-custom presentations don't have this problem). The presented view controller is owned by the transition's container view, which is a temporary view provided by UIKit that we have next to no dominion over. If we anchor the presented view to that transient container, it only works on certain OS versions; not to mention, Apple has never suggested doing this.
UPDATE 1: There is no way to consistently handle a double-height status bar with custom modal presentations. I think Apple botched it here and I suspect they will eventually phase it out.
UPDATE 2: The double-height status bar has been phased out and no longer exists on non-edge-to-edge devices.
My answer is: You should not use constraints in case of custom modal presentations
Therefore I know your pain, so I will try to help you to save time and effort by providing some hints which I suddenly revealed.
Example case:
Card UI animation like follows:
Terms for further use:
Parent - UIViewController with "Detail" bar button item
Child - UIViewController with "Another"
Troubles you mentioned began, when my animation involved size change along with the movement. It causes different kinds of effects including:
Parent's under-status-bar area appeared and disappeared
Parent's subviews were animated poorly - jumps, duplication and other glitches.
After few days of debugging and searching I came up with the following solution (sorry for some magic numbers ;)):
UIView.animate(withDuration: transitionDuration(using: transitionContext),
delay: 0,
usingSpringWithDamping: 1,
initialSpringVelocity: 0.4,
options: .curveEaseIn, animations: {
toVC.view.transform = CGAffineTransform(translationX: 0, y: self.finalFrame.minY)
toVC.view.frame = self.finalFrame
toVC.view.layer.cornerRadius = self.cornerRadius
fromVC.view.layer.cornerRadius = self.cornerRadius
var transform = CATransform3DIdentity
transform = CATransform3DScale(transform, scale, scale, 1.0)
transform = CATransform3DTranslate(transform, 0, wdiff, 0)
fromVC.view.layer.transform = transform
fromVC.view.alpha = 0.6
}) { _ in
transitionContext.completeTransition(!transitionContext.transitionWasCancelled)
}
Main point here is, that You have to use CGAffineTransform3D to avoid animation problems and problems with subviews animation (2D Transforms are not working for unknown reasons).
This approach fixes, I hope, all your problems without using constraints.
Feel free to ask questions.
UPD: According to In-Call status bar
After hours of all possible experiments and examining similar projects like this and this and stackoverflow questions like this, this (it's actually fun, OPs answer is there) and similar I am totally confused. Seems like my solution handles Double status bar on UIKit level (it adjusts properly), but the same movement is ignoring previous transformations. The reason is unknown.
Code samples:
You can see the working solution here on Github
P.S. I'm not sure if it's ok to post a GitHub link in the answer. I'd appreciate for an advice how to post 100-300 lines code In the answer.
I've been struggling with double-height statusBar in my current project and I was able to solve almost every issue (the last remaining one is a very strange transformation issue when the presentingViewController is embedded inside a UITabBarController).
When the height of the status bar changes, a notification is posted.
Your UIPresentationController subclass should subscribe to that particular notification and adjust the frame of the containerView and its subviews:
UIApplication.willChangeStatusBarFrameNotification
Here is an example of code I'm using:
final class MyCustomPresentationController: UIPresentationController {
// MARK: - StatusBar
private func subscribeToStatusBarNotifications() {
let notificationName = UIApplication.willChangeStatusBarFrameNotification
NotificationCenter.default.addObserver(self, selector: #selector(statusBarWillChangeFrame(notification:)), name: notificationName, object: nil)
}
#objc private func statusBarWillChangeFrame(notification: Notification?) {
if let newFrame = notification?.userInfo?[UIApplication.statusBarFrameUserInfoKey] as? CGRect {
statusBarWillChangeFrame(to: newFrame)
} else {
statusBarWillChangeFrame(to: .zero)
}
}
func statusBarWillChangeFrame(to newFrame: CGRect) {
layoutContainerView(animated: true)
}
// MARK: - Object Lifecycle
deinit {
// Unsubscribe from all notifications
NotificationCenter.default.removeObserver(self)
}
// MARK: - Layout
/// Called when the status-bar is about to change its frame.
/// Relayout the containerView and its subviews
private func layoutContainerView(animated: Bool) {
guard let containerView = self.containerView else { return }
// Retrieve informations about status-bar
let statusBarHeight = UIApplication.shared.statusBarFrame.height
let normalStatusBarHeight = Constants.Number.statusBarNormalHeight // 20
let isStatusBarNormal = statusBarHeight ==~ normalStatusBarHeight
if animated {
containerView.frame = …
updatePresentedViewFrame(animated: true)
} else {
// Update containerView frame
containerView.frame = …
updatePresentedViewFrame(animated: false)
}
}
func updatePresentedViewFrame(animated: Bool) {
self.presentedView?.frame = …
}
}
Normally, we can do an interactive transitioning with animateTransition of UIViewControllerAnimatedTransitioning and updating progress via UIPercentDrivenInteractiveTransition.
Question:
How to have the interactive transitioning at first, then as we pass a certain threshold, perform a different ending animation?
What I want to achieve here is something like dismissing App store's Today card (https://gph.is/2qgcGHd). We can interactively shrink the card by panning a left edge of the screen. Then when it reaches the point, the card animates back to home page without any interactivity. It seems like a combination of interactive + animate transition to me.
What I've tried:
I tried doing this in UIView.animateWithKeyFrames by dividing into two parts of animation with 0.5 relative times for each. Then as the progress reach 0.5, I call finish() (of UIPercentDrivenInteractiveTransition) to have the second animation performing. It has some glitches there and it's like a hack. Want to know if there's a better way to do this.
In the end, I use UIView.animateKeyFramesand dividing the interactive transition into two-part animation (as explained in the question):
let progressUntilDismissing = 0.4
UIView.animateKeyframes(withDuration: 0.5, delay: 0, options: [], animations: {
UIView.addKeyframe(withRelativeStartTime: 0.0,
relativeDuration: progressUntilDismissing,
animations: {
// interactive dismissing animation...
})
UIView.addKeyframe(withRelativeStartTime: progressUntilDismissing,
relativeDuration: (1 - progressUntilDismissing),
animations: {
// closing dismissing animation...
})
}) { (finished) in
//...
}
Then in the pan gesture recognizer, I calculate the pan progress and determine if it passes progressUntilDismissing or not.
If yes, call finish() on UIPercentDrivenInteractiveTransition subclass, it will animate the closing dismissing animation automatically.
In case anyone is curious, this is what I'm playing with:
AppStoreTodayInteractiveTransition
I was wondering how can i show a 'No Internet Connection' Just how like Instagram does it,
As an Example :
That see-through custom message animating to show under the navigationController . Would really love to get this to my project ,
thank you for you help
So here's a pic of the storyboard like this :-
"No internet connection" is a label, and the red view underneath is just to test the see through property of the label. If you are designing the UI in code, you can probably make a label similar to mine and place it to the top of the Navigation bar by using it's frame property.
The button here I'm using is just to show the label pop up on the scene (since it's just a demo answer). In your case, if the internet is not available, you will proceed to show the pop up.
So if you are making the UI in code, make sure to make the label in the viewDidLoad method. I have made an IBOutlet and the viewDidLoad now looks like this:-
override func viewDidLoad() {
super.viewDidLoad()
let transform = CGAffineTransform(translationX: 0, y: -label.frame.height)
label.alpha = 0
label.transform = transform
}
On the view loading, I'm moving the label behind the navigation bar, using CGAffineTransform. The distance, how much to move up is the label's height, since we don't want any part to be clipped on the scene.
Next step, is just a fix. I'm making alpha = 0, because navBar is translucent is nature and hence will change it's colour, since our label is behind it. So setting alpha to 0, takes care of it, and in third step apply the transform.
Now, if the internet connection is not available, we should pop out the label under the navBar. The code will look something like this:-
fun checkInternet() {
// called by some of your observer, which checks for changes in internet connection
if !isInternetAvailable {
UIView.animate(withDuration: 0.5, delay: 0, usingSpringWithDamping: 0.3, initialSpringVelocity: 0, options: .curveLinear, animations: {
self.label.alpha = 0.5
self.label.transform = .identity
}, completion: nil)
}
}
So here, I'll show the pop up with an animation using UIView.animate with some spring damping, so it has a nice bouncy effect to it. I'm setting the alpha to 0.5, since you mentioned you want a see through label, and I'm setting the label to a transform which will bring it back to it's original position when it was created, that's why I'm using .identity.
You can play around usingSpringWithDamping values and change options to have different effects.
func fadeLightBar(){
UIView.animateWithDuration(fadeTime, delay: 0, options: UIViewAnimationOptions.AllowUserInteraction, animations: { [unowned self] () -> Void in
//self.lightBar.backgroundColor = RandomFlatColor()
self.lightBar.backgroundColor = GradientColor(UIGradientStyle.LeftToRight, self.lightBar.frame, [RandomFlatColor(), RandomFlatColor()])
}) { (stuff Bool) -> Void in
}
}
I want to fade a UIView from color to color. But, I want the UIView to be gradient color.
Doing the standard color-to-color works great. However, when I do the gradient, there is no fading at all. It just changes abruptly every X seconds.
I'm using this framework to generate gradients: https://github.com/ViccAlexander/Chameleon#gradient-colors-1
The framework works in its way, not simply change the color. I think it manipulate the layer by adding a CAGradientLayer on it. If so, it is impossible to animate adding a layer.
If you want to actualize the fading, you actually can do it yourself by adding a CAGradientLayer and animate its alpha
I'm struggling to figure out how to allow user interaction with a view as it's being animated.
Here's the situation: I have a UIView cardView which holds card subviews. The cards are draggable tiles, similar to how the cards in Tinder are draggable/swipeable.
I am trying to fade out the card using animateWithDuration by animating to cardView.alpha = 0. Logically, this will also fade out all of the subviews (card objects). In this specific case, I am only targeting one card subview. However, during the animation, I am unable to drag/interact with the card.
Here is the code I'm using:
UIView.animateWithDuration(
duration,
delay: 0,
options: UIViewAnimationOptions.AllowUserInteraction,
animations: {self.cardView.alpha = 0}
) {
_ in
println("Card faded out")
card.removeFromSuperview()
}
Why doesn't this work? Any help will be appreciated. Thank you!!
I think you can find the answer in this previous post.
The interesting bit of the post is:
UIView's block animation by default blocks user interaction, and to get around it you need to pass UIViewAnimationOptionAllowUserInteraction as one of the options.
I fixed this problem by setting alpha to 0.1 instead of 0.0. I'm not sure if that will work in your case, but it shows that the event handling code thought that the view was not visible and disabled interaction even with the UIViewAnimationOptionAllowUserInteraction flag set. Oddly, setting the alpha to 0.01 did not work, so there is a threshold of visibility you have to stay above.
Swift 5
UIView.animateKeyframes(withDuration: 0.5, delay: 0, options: [.repeat, .autoreverse, .allowUserInteraction], animations: {
self.customButton.backgroundColor = .none
}, completion: nil)
The issue is with the Alpha value of 0. Alpha values of a certain proximity to Zero will remove the view from the view responder hierarchy. The fix here is to make the alpha setting to this:
self.cardView.alpha = 0.011
The view will still be invisible but not removed from the responder chain. From my testing the minimum amount is the following:
extension CGFloat {
static let minAlphaForTouchInput: CGFloat = 0.010000001
}