I'm developing an app using Xcode 9.2 and swift 4 and I needed to allow just one view in my app to change to landscape, so I added the code below to my AppDelegate
func application(_ application: UIApplication, supportedInterfaceOrientationsFor window: UIWindow?) -> UIInterfaceOrientationMask {
if globalVariables.gIsDosageView == "Y" {
if UIDevice.current.orientation == .landscapeLeft || UIDevice.current.orientation == .landscapeRight {
return UIInterfaceOrientationMask.all;
} else {
return UIInterfaceOrientationMask.portrait;
}
} else {
return UIInterfaceOrientationMask.portrait;
}
}
The global variable is set to "N" on every other controller and so only DosageView has it set to "Y". In the DosageView controller I added this method to help with the transition.
override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
hideViews()
if size.width < 400 {
DispatchQueue.main.async() {
self.userImg.isHidden = false
self.burgerImg.isHidden = false
self.deviceImg.isHidden = false
self.portraitView.isHidden = false
self.landscapeView.isHidden = true
}
}
else {
DispatchQueue.main.async() {
self.userImg.isHidden = true
self.burgerImg.isHidden = true
self.deviceImg.isHidden = true
self.portraitView.isHidden = true
self.landscapeView.isHidden = false
self.loadLandscapeView()
}
}
}
I've set up a LandscapeView and a PortraitView and the method above helps to toggle between them and it all works fine. If I move to the next view or return to the main screen and then return to the DosageView and then change the orientation to Landscape it works but if I go to the next view and then from there to the Connect view and connect (via BLE, NFC or QR) it then returns to the DosageView. When I change the orientation to Landscape it changes back to the Connect view. There is no direct link between these two views as you have to go through the Instruction view to get to Connect View for the DosageView, so how can this happen?
When I run it under debug and put a breakpoint in the ViewDidLoad on Connect View, it runs every time the DosageView changes to Landscape. If anyone can tell me what is going on I would be grateful as this is driving me crazy.
It was actually a colleague who sorted this for me and as he correctly pointed out it was a Lottie run call causing the problem. For anyone using Lottie and experiencing this problem, simply check your animation code. I had originally plagiarised code from a Splash screen as below
splashAnimation!.loopAnimation = false
splashAnimation!.play(fromProgress: 0,
toProgress: 1.0,
withCompletion: { (finished) in
let storyboard = UIStoryboard(name: "Main", bundle: nil)
let controller = storyboard.instantiateViewController(withIdentifier: "Menu")
self.present(controller, animated: true, completion: nil)
})
This code works fine as it moves on to the main screen on completion. However, the screen that was causing the problems moves between two different screens and to fix the problem, my colleague simply removed the withCompletion part as below
splashAnimation!.loopAnimation = true
splashAnimation!.play(fromProgress: 0,
toProgress: 1.0)
Related
I am trying to add alpha to the background view when tapped on a button. So far achieved adding blur but alpha not so much.
How can I add alpha to the background so that when the bottom sheet appears background will be darker and disabled.
let maxDimmedAlpha: CGFloat = 0.2
lazy var dimmedView: UIView = {
let view = UIView()
view.backgroundColor = .black
view.alpha = maxDimmedAlpha
return view
}()
#objc func shareBtnClick() {
dimmedView.frame = self.parentVC.view.bounds
dimmedView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
self.parentVC.view.addSubview(dimmedView)
if self.parentVC.navigationController != nil {
if self.parentVC.navigationController?.viewControllers.count == 1 {
showBottomSheet()
} else {
NotificationCenter.default.post(name: NSNotification.Name("ShowBottomSheet"), object: nil, userInfo: ["itemId": modalSheet(), "delegate": self])
}
} else {
showBottomSheet()
}
}
func showBottomSheet() {
let modalSheet = MainBottomSheet()
modalSheet.data = self.modalSheet()
modalSheet.delegate = self
modalSheet.modalPresentationStyle = .overCurrentContext
self.parentVC.present(modalSheet, animated: true)
}
I was able to produce the dimmed effect using this code in XCode, I'm not sure why it won't work in your project but there is an easy way to debug this.
I suggest using Debug View Hierarchy, one of XCode's best tools in my opinion. This allows you to separate every single layer of the user interface. This way, you can see if your dimmedView is actually being added to the parent view and that its frame is matching the parent view's bounds.
Keep in mind if your background is dark, you won't see this dimmedView because its backgroundColor is set to UIColor.black.
Debug View Hierarchy button
I'm setting up the Settings page (in SettingsView class) where users can set «On» / «Off» for the background parallax effect. The selection is saved in UserDefaults().string(forKey: "parallaxStatus"). In the viewWillAppear of ViewController class, I checked the parallaxStatus. If the status of the parallax effect is «On», then this effect is displayed. If the status is «Off», then nothing should happen.
The problem appeared when parallaxStatus changed from «On» to «Off» In this case, the parallax effect still displayed before I reload the View. But if parallaxStatus changed from «Off» to «On», the function works well without reloading the View.
Bellow is the code of viewWillAppear function. Thanks for any help or hint.
override func viewWillAppear(_ animated: Bool) {
let parallaxStatus = UserDefaults().string(forKey: "parallaxStatus")
if parallaxStatus == "On" {
let min = CGFloat(-40)
let max = CGFloat(40)
let xMotion = UIInterpolatingMotionEffect(keyPath: "layer.transform.translation.x", type: .tiltAlongHorizontalAxis)
xMotion.minimumRelativeValue = min
xMotion.maximumRelativeValue = max
let yMotion = UIInterpolatingMotionEffect(keyPath: "layer.transform.translation.y", type: .tiltAlongVerticalAxis)
yMotion.minimumRelativeValue = min
yMotion.maximumRelativeValue = max
let motionEffectGroup = UIMotionEffectGroup()
motionEffectGroup.motionEffects = [xMotion,yMotion]
bgImage.addMotionEffect(motionEffectGroup) } else { }
}
1- You should use a bool value in userDefaults
UserDefaults.standard.bool(forKey: "parallaxStatusOn") // default is false
2- viewWillAppear is called when you dimiss a presented / poped vc so in your case , you use a settingsView not vc verify it's being called by other KVO or any event driven notifier
3- if the state is on and changed to off , verify you remove the motion effects with if the vc is still appeared ( not deallocated btw do it in else of check )
bgImage.motionEffects.forEach { bgImage.removeMotionEffect($0) }
I want to create an animation like the iOS app facebook at tabswitch[1]. I have already tried to develop some kind of animation, the problem that occurs is that the old view controller becomes invisible directly on the switch, instead of fading out slowly while the new controller is sliding in fast.
I've found this SO question How to animate Tab bar tab switch with a CrossDissolve slide transition? but the as correct marked solution does not really work for me (it is not a slide it is a fade transition). What I'd also like to get is the function to make slide left or right to switch the tabs. Like it was on a older version of facebook.
What I've got so far is this:
extension TabBarController: UITabBarControllerDelegate {
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
guard let fromView = selectedViewController?.view,
let toView = viewController.view else { return false }
if fromView != toView {
toView.transform = CGAffineTransform(translationX: -90, y: 0)
UIView.animate(withDuration: 0.25, delay: 0.0, options: .curveEaseInOut, animations: {
toView.transform = CGAffineTransform(translationX: 0, y: 0)
})
}; return true
}
}
class TabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
delegate = self
}
}
How to fix this?
[1]
I would very much like to add a gif from the Facebook app. The problem is that I don't want to censor the video and just reveal too much of my data. (Even if fb already has them). Also on youtube I didn't find a suitable recording. Please try it yourself in the fb app in iOS.
You can use the following idea: https://samwize.com/2016/04/27/making-tab-bar-slide-when-selected/
Also, here's the code updated to Swift 4.1 and I also removed the force unwrappings:
import UIKit
class MyTabBarController: UITabBarController {
override func viewDidLoad() {
super.viewDidLoad()
delegate = self
}
}
extension MyTabBarController: UITabBarControllerDelegate {
func tabBarController(_ tabBarController: UITabBarController, shouldSelect viewController: UIViewController) -> Bool {
guard let tabViewControllers = tabBarController.viewControllers, let toIndex = tabViewControllers.index(of: viewController) else {
return false
}
animateToTab(toIndex: toIndex)
return true
}
func animateToTab(toIndex: Int) {
guard let tabViewControllers = viewControllers,
let selectedVC = selectedViewController else { return }
guard let fromView = selectedVC.view,
let toView = tabViewControllers[toIndex].view,
let fromIndex = tabViewControllers.index(of: selectedVC),
fromIndex != toIndex else { return }
// Add the toView to the tab bar view
fromView.superview?.addSubview(toView)
// Position toView off screen (to the left/right of fromView)
let screenWidth = UIScreen.main.bounds.size.width
let scrollRight = toIndex > fromIndex
let offset = (scrollRight ? screenWidth : -screenWidth)
toView.center = CGPoint(x: fromView.center.x + offset, y: toView.center.y)
// Disable interaction during animation
view.isUserInteractionEnabled = false
UIView.animate(withDuration: 0.3,
delay: 0.0,
usingSpringWithDamping: 1,
initialSpringVelocity: 0,
options: .curveEaseOut,
animations: {
// Slide the views by -offset
fromView.center = CGPoint(x: fromView.center.x - offset, y: fromView.center.y)
toView.center = CGPoint(x: toView.center.x - offset, y: toView.center.y)
}, completion: { finished in
// Remove the old view from the tabbar view.
fromView.removeFromSuperview()
self.selectedIndex = toIndex
self.view.isUserInteractionEnabled = true
})
}
}
So, you need to subclass UITabBarController and you also have to write the animation part, you can tweak the animation options (delay, duration, etc).
I hope it helps, cheers!
I've never seen Facebook so I don't know what the animation is. But you can have any animation you like when a tab bar controller changes its tab (child view controller), coherently and without any hacks, using the built-in mechanism that Apple provides for adding custom animation to a transition between view controllers. It's called custom transition animation.
Apple first introduced this mechanism in 2013. Here's a link to their video about it: https://developer.apple.com/videos/play/wwdc2013/218/
I immediately adopted this in my apps, and I think it makes them look a lot spiffier. Here's a demo of a tab bar controller custom transition that I like:
The really cool thing is that once you've decided what animation you want, making the transition interactive (i.e. drive it with a gesture instead of a button click) is easy:
Now, you might be saying: Okay, but that's not quite the animation I had in mind. No problem! Once you've got the hang of the custom transition architecture, changing the animation to anything you like is easy. In this variant, I just commented out one line so that the "old" view controller doesn't slide away:
So let your imagination run wild! Adopt custom transition animations, the way that iOS intends.
If you want something for pushViewController navigation, you can try this.
However, when switching between tabs on a TabBarController, this will not work. For that, I'd go with #mihai-erős 's solution
Change the Animation duration as per your liking, and assign this class to your navigation segues, for a Slide Animation.
class CustomPushSegue: UIStoryboardSegue {
override func perform() {
// first get the source and destination view controllers as UIviews so that they can placed in navigation stack
let sourceVCView = self.source.view as UIView!
let destinationVCView = self.destination.view as UIView!
let screenWidth = UIScreen.main.bounds.size.width
//create the destination view's rectangular frame i.e starting at 0,0 and equal to screenwidth by screenheight
destinationVCView?.transform = CGAffineTransform(translationX: screenWidth, y: 0)
//the destinationview needs to be placed on top(aboveSubView) of source view in the app window stack before being accessed by nav stack
// get the window and insert destination View
let window = UIApplication.shared.keyWindow
window?.insertSubview(destinationVCView!, aboveSubview: sourceVCView!)
// the animation: first remove the source out of screen by moving it at the left side of it and at the same time place the destination to source's position
// Animate the transition.
UIView.animate(withDuration: 0.3, animations: { () -> Void in
sourceVCView?.transform = CGAffineTransform(translationX: -screenWidth,y: 0)
destinationVCView?.transform = CGAffineTransform.identity
}, completion: { (Finished) -> Void in
self.source.present(self.destination, animated: false, completion: nil)
})
}
}
Could use some help troubleshooting an issue with a SpriteKit scene.
I have a scene that displays some coins in the main section of the app.
When I present a viewcontroller from the bottom I have no issue. Same for tab bar navigation, no issues.
Here is the view as it should always be displayed.
The issue comes only when I present a viewcontroller from the side.
When the new viewcontroller is dismissed, the scene works, but is distorted.
this is how it is displayed after a viewcontroller is displayed modally and later on dismissed.
EDIT: I forgot to mention that if I swipe vertically on the distorted scene, the distortion is fixed and all is good.
Here is some of the code in viewDidAppear of the viewcontroller.
Thanks for the help.
EDIT 2:
I just tested the app on a iPhone 5 using iOS 10 and the issue doesn't happen. Any chance this might be iOS 11 related?
func configureScene(_ completion: () -> Void) {
defer { completion() }
guard wScene == nil else { return }
let skView = SKView(frame: self.view.frame)
skView.isUserInteractionEnabled = false
skView.backgroundColor = .clear
wScene = WScene(size: view.frame.size)
wScene.backgroundColor = .clear
skView.presentScene(wScene)
view.insertSubview(skView, belowSubview: collectionView)
if let buttonsObstacle = doubleButton?.buttonsView {
let obstacleSize = CGSize.init(width: buttonsObstacle.frame.width, height: buttonsObstacle.frame.height)
obstacle = SKSpriteNode.init(color: .clear, size: obstacleSize)
guard let obstacle = obstacle else { return }
obstacle.name = WScene.obstacleNodeName
let convertedOrigin = view.convert(buttonsObstacle.center, from: buttonsObstacle.superview)
let skConvertedOrigin = skView.convert(convertedOrigin, to: wScene)
obstacle.position = skConvertedOrigin
obstacle.physicsBody = SKPhysicsBody(rectangleOf: obstacleSize)
obstacle.physicsBody?.allowsRotation = false
obstacle.physicsBody?.isDynamic = false
source.scrollHandler = { [weak self] (scrollView) in
guard let strongSelf = self else { return }
strongSelf.buttonsMoved(inView: skView, withScroll: scrollView)
}
wScene.addChild(obstacle)
presenter.loadData()
}
}
I solved my issue.
It was related to the new iOS 11 adjustedContentInset property.
My Coin SK scene was being moved by the scroll handler when the view appeared after a modal transition.
My solution is to disable the scrolling for the first 0.1 second after the view appears. In this way iOS 11 doesn't touch the coins anymore while users are able to scroll correctly because they interact with the view most of the time after at least 0.1 seconds.
is it possible to determine whether my UIView is visible to the user or not?
My View is added as subview several times into a Tab Bar Controller.
Each instance of this view has a NSTimer that updates the view.
However I don't want to update a view which is not visible to the user.
Is this possible?
Thanks
For anyone else that ends up here:
To determine if a UIView is onscreen somewhere, rather than checking superview != nil, it is better to check if window != nil. In the former case, it is possible that the view has a superview but that the superview is not on screen:
if (view.window != nil) {
// do stuff
}
Of course you should also check if it is hidden or if it has an alpha > 0.
Regarding not wanting your NSTimer running while the view is not visible, you should hide these views manually if possible and have the timer stop when the view is hidden. However, I'm not at all sure of what you're doing.
You can check if:
it is hidden, by checking view.hidden
it is in the view hierarchy, by checking view.superview != nil
you can check the bounds of a view to see if it is on screen
The only other thing I can think of is if your view is buried behind others and can't be seen for that reason. You may have to go through all the views that come after to see if they obscure your view.
This will determine if a view's frame is within the bounds of all of its superviews (up to the root view). One practical use case is determining if a child view is (at least partially) visible within a scrollview.
Swift 5.x:
func isVisible(view: UIView) -> Bool {
func isVisible(view: UIView, inView: UIView?) -> Bool {
guard let inView = inView else { return true }
let viewFrame = inView.convert(view.bounds, from: view)
if viewFrame.intersects(inView.bounds) {
return isVisible(view: view, inView: inView.superview)
}
return false
}
return isVisible(view: view, inView: view.superview)
}
Older swift versions
func isVisible(view: UIView) -> Bool {
func isVisible(view: UIView, inView: UIView?) -> Bool {
guard let inView = inView else { return true }
let viewFrame = inView.convertRect(view.bounds, fromView: view)
if CGRectIntersectsRect(viewFrame, inView.bounds) {
return isVisible(view, inView: inView.superview)
}
return false
}
return isVisible(view, inView: view.superview)
}
Potential improvements:
Respect alpha and hidden.
Respect clipsToBounds, as a view may exceed the bounds of its superview if false.
The solution that worked for me was to first check if the view has a window, then to iterate over superviews and check if:
the view is not hidden.
the view is within its superviews bounds.
Seems to work well so far.
Swift 3.0
public func isVisible(view: UIView) -> Bool {
if view.window == nil {
return false
}
var currentView: UIView = view
while let superview = currentView.superview {
if (superview.bounds).intersects(currentView.frame) == false {
return false;
}
if currentView.isHidden {
return false
}
currentView = superview
}
return true
}
I benchmarked both #Audrey M. and #John Gibb their solutions.
And #Audrey M. his way performed better (times 10).
So I used that one to make it observable.
I made a RxSwift Observable, to get notified when the UIView became visible.
This could be useful if you want to trigger a banner 'view' event
import Foundation
import UIKit
import RxSwift
extension UIView {
var isVisibleToUser: Bool {
if isHidden || alpha == 0 || superview == nil {
return false
}
guard let rootViewController = UIApplication.shared.keyWindow?.rootViewController else {
return false
}
let viewFrame = convert(bounds, to: rootViewController.view)
let topSafeArea: CGFloat
let bottomSafeArea: CGFloat
if #available(iOS 11.0, *) {
topSafeArea = rootViewController.view.safeAreaInsets.top
bottomSafeArea = rootViewController.view.safeAreaInsets.bottom
} else {
topSafeArea = rootViewController.topLayoutGuide.length
bottomSafeArea = rootViewController.bottomLayoutGuide.length
}
return viewFrame.minX >= 0 &&
viewFrame.maxX <= rootViewController.view.bounds.width &&
viewFrame.minY >= topSafeArea &&
viewFrame.maxY <= rootViewController.view.bounds.height - bottomSafeArea
}
}
extension Reactive where Base: UIView {
var isVisibleToUser: Observable<Bool> {
// Every second this will check `isVisibleToUser`
return Observable<Int>.interval(.milliseconds(1000),
scheduler: MainScheduler.instance)
.map { [base] _ in
return base.isVisibleToUser
}.distinctUntilChanged()
}
}
Use it as like this:
import RxSwift
import UIKit
import Foundation
private let disposeBag = DisposeBag()
private func _checkBannerVisibility() {
bannerView.rx.isVisibleToUser
.filter { $0 }
.take(1) // Only trigger it once
.subscribe(onNext: { [weak self] _ in
// ... Do something
}).disposed(by: disposeBag)
}
Tested solution.
func isVisible(_ view: UIView) -> Bool {
if view.isHidden || view.superview == nil {
return false
}
if let rootViewController = UIApplication.shared.keyWindow?.rootViewController,
let rootView = rootViewController.view {
let viewFrame = view.convert(view.bounds, to: rootView)
let topSafeArea: CGFloat
let bottomSafeArea: CGFloat
if #available(iOS 11.0, *) {
topSafeArea = rootView.safeAreaInsets.top
bottomSafeArea = rootView.safeAreaInsets.bottom
} else {
topSafeArea = rootViewController.topLayoutGuide.length
bottomSafeArea = rootViewController.bottomLayoutGuide.length
}
return viewFrame.minX >= 0 &&
viewFrame.maxX <= rootView.bounds.width &&
viewFrame.minY >= topSafeArea &&
viewFrame.maxY <= rootView.bounds.height - bottomSafeArea
}
return false
}
I you truly want to know if a view is visible to the user you would have to take into account the following:
Is the view's window not nil and equal to the top most window
Is the view, and all of its superviews alpha >= 0.01 (threshold value also used by UIKit to determine whether it should handle touches) and not hidden
Is the z-index (stacking value) of the view higher than other views in the same hierarchy.
Even if the z-index is lower, it can be visible if other views on top have a transparent background color, alpha 0 or are hidden.
Especially the transparent background color of views in front may pose a problem to check programmatically. The only way to be truly sure is to make a programmatic snapshot of the view to check and diff it within its frame with the snapshot of the entire screen. This won't work however for views that are not distinctive enough (e.g. fully white).
For inspiration see the method isViewVisible in the iOS Calabash-server project
The simplest Swift 5 solution I could come up with that worked in my situation (I was looking for a button embedded in my tableViewFooter).
John Gibbs solution also worked but in my cause I did not need all the recursion.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let viewFrame = scrollView.convert(targetView.bounds, from: targetView)
if viewFrame.intersects(scrollView.bounds) {
// targetView is visible
}
else {
// targetView is not visible
}
}
In viewWillAppear set a value "isVisible" to true, in viewWillDisappear set it to false. Best way to know for a UITabBarController subviews, also works for navigation controllers.
Another useful method is didMoveToWindow()
Example: When you push view controller, views of your previous view controller will call this method. Checking self.window != nil inside of didMoveToWindow() helps to know whether your view is appearing or disappearing from the screen.
This can help you figure out if your UIView is the top-most view. Can be helpful:
let visibleBool = view.superview?.subviews.last?.isEqual(view)
//have to check first whether it's nil (bc it's an optional)
//as well as the true/false
if let visibleBool = visibleBool where visibleBool { value
//can be seen on top
} else {
//maybe can be seen but not the topmost view
}
try this:
func isDisplayedInScreen() -> Bool
{
if (self == nil) {
return false
}
let screenRect = UIScreen.main.bounds
//
let rect = self.convert(self.frame, from: nil)
if (rect.isEmpty || rect.isNull) {
return false
}
// 若view 隐藏
if (self.isHidden) {
return false
}
//
if (self.superview == nil) {
return false
}
//
if (rect.size.equalTo(CGSize.zero)) {
return false
}
//
let intersectionRect = rect.intersection(screenRect)
if (intersectionRect.isEmpty || intersectionRect.isNull) {
return false
}
return true
}
In case you are using hidden property of view then :
view.hidden (objective C) or view.isHidden(swift) is read/write property. So you can easily read or write
For swift 3.0
if(view.isHidden){
print("Hidden")
}else{
print("visible")
}