I have a UICollectionViewController with an inputAccessoryView. Everything works great until I present a UIViewController, and then the accessory view disappears. Trying to get basic Chat application features.
I have implemented in the collection view:
override var inputAccessoryView: UIView? {
get {
return inputContainerView
}
}
override var canBecomeFirstResponder: Bool {
return true
}
override func becomeFirstResponder() -> Bool {
return true
}
As suggested in multiple other threads, I also call (in the collection view),
view.resignFirstResponder()
view.inputAccessoryView?.reloadInputViews()
view.becomeFirstResponder()
after dismissing the UIViewController but to no avail. print(view.isFirstResponder) still prints false. I have tried almost every combination of the above three lines in numerous different places in my code. I think I'm missing something simple.
The animation to present and dismiss view controller might be causing issue or You haven't maintained a global ivar for the view you have setted as input accessory view. Try creating a readonly ivar for the accessoryview so only one instance is allocated and maintained through out VC life cycle. Then ensure to set it back to the textfields before calling reloadInputViews.
After a few days I finally figured out something that works... I think I was trying to present the loginController before the collectionView was set as the first responder. Instead of just calling present I called this function:
func presentLoginControllerAfterImFirstResponder(fromUser: Bool) {
// Starts a timer
Timer.scheduledTimer(withTimeInterval: 0.01, repeats: true) { (timer) in
// Is this view the first responder?
if self.isFirstResponder {
// Creates the loginController
let loginController = LoginController()
// Presents it
self.present(loginController, animated: fromUser, completion: {
// Once presented, sets rootViewController = self
loginController.rootViewController = self
})
// Stop the timer
timer.invalidate()
}
}
}
This works now. I guess the collectionView needed some time to set itself as the first responder? I can present and dismiss the loginController no problem and the inputAccessoryView remains.
Related
I'm trying to create a timer app. I have a singleton class with a Timer which fires every x minutes. Using custom delegate I pass the data to active view controller and update the value in a label. If the data is when the count is y, I perform push and update the count in another view controller's label.
When application is in foreground I didn't get any problem. If the application is in background state the counter keeps running and label text isn't updated and push isn't performed. Still I'm in first view controller. How to solve this?
like I mentioned in your comment section. when you app is in the background state you shouldn't continuously updating your UI as it is pointless. when user tapped back into your app your view controller will call a function viewDidAppear(animated). In that function you can check timer condition then present second view controller if needed. I'll post a sample code below
class FirstViewController : UIViewController {
var timerExpiration = false
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
if timerExpiration {
let vc = SecondViewController()
present(vc, animated: true, completion: nil)
}
}
}
class SecondViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
}
You need to wrap all foreground UI tasks in a block like this
DispatchQueue.main.async {
// do your UI stuff here, like
// label.text = "Main thread stuff"
}
Put this in your timer action.
I have a basic app with a UITabBarController as the root view controller. When a user of the app is not signed in I'm showing a modal controller via window!.rootViewController!.present(viewController, animated: true) in my AppDelegate. This works fine on all iPhone models, however the following happens on any iPad:
The background color of the SignInController is visible during the transition. Now comes the weird thing: When I change the view in Interface Builder to an iPad the bug is gone like so:
Changing the background color back to the transparent default removes at least the white background, however the view is still animating from the left bottom which is something I don't want. And by the way, changing the view in Interface Builder breaks the animation on all iPhones. Changing it back fixes it but breaks again all iPads.
This is the code (using ReSwift for state management):
func newState(state: State) {
switch (previousState.session, state.session) {
case (.loading, .notSignedIn), (.signedIn, .loading):
(window!.rootViewController! as! UITabBarController).selectedIndex = 0
let viewController = storyboard.instantiateViewController(withIdentifier: "SignInViewController")
window!.rootViewController!.present(viewController, animated: true, completion: nil)
default:
// more stuff
break
}
}
EDIT: Added the actual code.
I fixed it! 😊
The problem was a combination of having an observer on keyboardWillShowNotification and a becomeFirstResponder in the viewWillAppear method of the presented controller.
Moving the becomeFirstResponder into viewDidAppear fixed all the problems!
Thanks man! Saved my day.. I'm presenting the keyboard from within a tableview cell - I fixed it like this:
private var canPresentKeyboard: Bool = false
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
canPresentKeyboard = true
if _currentlySelectedIdType != .image {
reload(section: .idType)
}
}
func configure(cell: NumberIdTableViewCellInput) {
cell.set(delegate: self)
if canPresentKeyboard {
cell.clearAndSetFirstResponder()
}
}
I know the code is a bit out of context, but I believe the intention is clear.
I want to refresh the whole page controller on back press.
I am navigating the viewcontroller using code.
My Code
let GTC = self.storyboard?.instantiateViewController(withIdentifier: "GoToCart")as! GoToCart
self.navigationController?.pushViewController(GTC, animated: true)
Using viewWillAppear to reload your UI. As you use navigationController?.pushViewController, the view will be retained and stored in stack.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// Reload the UI
}
viewWillAppear(_:)
viewWillAppear is called the first time the view is displayed as well as when the view is displayed again, so it can be called multiple times during the life of the view controller object. It’s called when the view is about to appear as a result of the user tapping the back button, when the view controller’s tab is selected in a tab bar controller etc. Make sure to call super.viewWillAppear() at some point in the implementation. You can refresh your UI in this method
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// Reload the UI
}
A better approach is to use protocol
Create protocol from where you want to pop back(GoToCart)
Create delegate variable in GoToCart
Extend GoToCart protocol in MainViewController
Give reference to GoToCart of MainViewController when
navigate
Define delegate Method in MainViewController
Then you can call delegate method from GoToCart
Example
In GoToCart: Write code below..
protocol GoCartControllerDelegate
{
func childViewControllerResponse(parameter)
}
class GoToCart:UIViewController
{
var delegate: ChildViewControllerDelegate?
....
}
Then in mainViewController implement the protocol function end extend to the protocol
class MainViewController:UIViewController,GoCartControllerDelegate
{
// Define Delegate Method
func childViewControllerResponse(parameter)
{
//...here update what you want to update according to the situation
}
}
2 Important thing
when navigating to the gocart controller code like this
let GTC = self.storyboard?.instantiateViewController(withIdentifier: "GoToCart")as! GoToCart
GTC.delegate = self
self.navigationController?.pushViewController(GTC, animated: true)
and when popping from gocartViewController
code like this
self.navigationController?.popViewController(animated:true)
self.delegate?.childViewControllerResponse(parameter)
My navigation controller intermittently will freeze on push. It seems to add the new view controller onto the stack, but the animation never takes place. I also have two other containers that hold view controllers on the screen, and I can interact with both of them just fine after the navigation controller freezes. The really interesting thing is if I try to push another view controller onto the navigation controller's stack, I noticed that there is an extra view controller on top of the stack (the view controller that I pushed initially that froze the navigation controller). So if I'm on the home screen (we'll call it VC-Home) and I try to push a new view (VC-1) and it freezes, then I try to push a new view (VC-2), this is what I see in the current stack before the push:
{ [VC-Home, VC-1] }
and after pushViewController is called, it remains the same; VC-2 is not added to the stack.
From what I can tell, the navigation controller starts the animation by making the previous view controller inactive before the animation begins, but then the animation never takes place, leaving the navigation controller in a frozen state.
I'm creating the new view controller from a storyboard by calling
UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("ViewController") so I don't think there's any issues there. I'm also not overriding pushViewController on the navigation bar. Some unique things about my app is that it is very high-res image heavy (using SDWebImage to manage that) and I always have three containers on the screen at once (one navigation controller, one view controller for search, and one interactive gutter/side/slideout menu).
CPU usage is low and memory usage is normal (steadily around 60-70MB on device when freezes occur).
Are there any ideas with what might be causing this or any debugging tips that could help me discover the real problem?
Update
There's no unique code for the UINavigationController since I'm just pushing using pushViewController(). Here's the code that calls it:
func didSelectItem(profile: SimpleProfile) {
let vc = UIStoryboard.profileViewController()
vc.profile = profile
navigationController?.pushViewController(vc, animated: true)
}
The ViewController that I pushed has the following code in viewDidLoad:
override func viewDidLoad() {
super.viewDidLoad()
button.roundView()
if let type = profile?.profileType {
//load multiple view controllers into a view pager based on type
let viewControllers = ProfileTypeTabAdapter.produceViewControllersBasedOnType(type)
loadViewPagerViews(viewControllers)
let topInset = headerView.bounds.height + tabScrollView.contentSize.height
if let viewPager = viewPager {
for view in viewPager.views {
if let tempView = view as? PagingChildViewController {
tempView.profile = fullProfile
tempView.parentVCDelegate = self
tempView.topInset = topInset
}
}
}
}
}
func loadViewPagerViews(viewControllers: [UIViewController]) {
viewPager?.views = viewControllers
viewPager?.delegate = self
//loading views into paging scroll view (using PureLayout to create constraints)
let _ = subviews.map { $0.removeFromSuperview() }
var i = 0
for item in views {
addSubview(item.view)
item.view.autoSetDimensionsToSize(CGSize(width: tabWidth, height: tabHeight))
if i == 0 {
item.view.autoPinEdgeToSuperviewEdge(.Leading)
} else if let previousView = views[i-1].view {
item.view.autoPinEdge(.Leading, toEdge: .Trailing, ofView: previousView)
}
if i == views.count {
item.view.autoPinEdgeToSuperviewEdge(.Trailing)
}
i += 1
}
contentSize = CGSize(width: Double(i)*Double(tabWidth), height: Double(tabHeight))
}
Update 2
I finally got it to freeze again. The app was in the background and I brought it back and tried pushing a view controller on the stack when it froze. I noticed an animation was taking place. I have a scrollview at the top of the page that pages through its content every 10 seconds (think of the app stores top banner). On this freeze, I noticed that the banner was mid-animation.
Here's the scrolling function from the my UIScrollView that gets called every 10 seconds:
func moveToNextItem() {
let pageWidth: CGFloat = CGRectGetWidth(frame)
let maxWidth: CGFloat = pageWidth * CGFloat(max(images.count, profileImages.count))
let contentOffset: CGFloat = self.contentOffset.x
let slideToX = contentOffset + pageWidth
//if this is the end of the line, stop the timer
if contentOffset + pageWidth == maxWidth {
timer?.invalidate()
timer = nil
return
}
scrollRectToVisible(CGRectMake(slideToX, 0, pageWidth, CGRectGetHeight(frame)), animated: true)
}
I don't recall ever having a push stop because of an animation/scroll taking place, but I could be wrong.
I've also rechecked the stack and the same situation as described above is still the case where [VC-Home, VC-1] is the stack and VC-2 is not pushed on. I've also gone through VC-1's variables and everything has loaded (data calls and image loads).
Update 3
This is getting stranger by the second. I've overriden pushViewController so I can put a breakpoint in there and do some debugging based on Alessandro Ornano's response. If I push a view controller unsuccessfully, then send my app to the background, put a breakpoint into the pushViewController call, and bring the app back, the breakpoint is immediately hit a number of times. If I then continue past all the hits, the next view controller suddenly becomes visible and the last view controller I tried to push is now on the stack as the last view controller. This means that the one that I see is still disabled, which essentially puts me in the same position as before.
We have faced the same problem couple of weeks back. And for our problem we narrowed it down to left-edge pop gesture recogniser. You can try and check if you can reproduce this problem using below steps
Try using the left edge pop gesture when there are no view controllers below it (i.e on root view controllers, your VC-Home controller)
Try clicking on any UI elements after this.
If you are able to reproduce the freeze, try disabling the interactivePopGestureRecognizer when the view controller stack have only one view controller.
Refer to this question for more details. Below is the code from the link for ease of reference.
- (void)navigationController:(UINavigationController *)navigationController
didShowViewController:(UIViewController *)viewController
animated:(BOOL)animate
{
if ([self respondsToSelector:#selector(interactivePopGestureRecognizer)])
{
if (self.viewControllers.count > 1)
{
self.interactivePopGestureRecognizer.enabled = YES;
}
else
{
self.interactivePopGestureRecognizer.enabled = NO;
}
}
}
Great answer by #Penkey Suresh! Saved my day! Here's a SWIFT 3 version with a small addition that made the difference for me:
func navigationController(_ navigationController: UINavigationController, didShow viewController: UIViewController, animated: Bool) {
if (navigationController.viewControllers.count > 1)
{
self.navigationController?.interactivePopGestureRecognizer?.delegate = self
navigationController.interactivePopGestureRecognizer?.isEnabled = true;
}
else
{
self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
navigationController.interactivePopGestureRecognizer?.isEnabled = false;
}
}
Just don't forget to add UINavigationControllerDelegate and set the navigationController?.delegate = self
Another important part is to assign the interactivePopGestureRecognizer to self or to nil accordingly.
I was thinking about intermittently freezing, main thread and SDWebImage.
Assuming that you using the image you downloaded from downloadImageWithURL:options:progress:completed:'s completed block .. if so, make sure you dispatch to the main queue before using using the image.
If you use the SDWebImageDownloader directly, the completion block (as you noted) will be invoked on a background queue, you can fix it using dispatch_async on the main queue from the completion.
Otherwise you can use:
SDWebImageManager downloadImageWithURL:options:progress:completed: (method that invokes the completion blocks on the main queue).
if the problem persist (just because you speaking about "..some unique things about my app is that it is very image heavy..") look also Common problems expecially the Handle image refresh know problems.
Add to your check also this nice snippet code:
import UIKit.UINavigationController
public typealias VoidBlock = (Void -> Void)
public extension UINavigationController
{
public func pushViewController(viewController: UIViewController, animated: Bool, completion: VoidBlock) {
CATransaction.begin()
CATransaction.setCompletionBlock(completion)
self.pushViewController(viewController, animated: animated)
CATransaction.commit()
}
}
maybe can help to understand if pushViewController finish, if finish with all viewControllers expected ..
Another test I try to make is to launch the app with iOS 8.x and iPhone 6+, because there are some issues in the pureLayout project around iOS 9. Can you send feedbacks around this test?
I've some suspicious also on the real scrollview dimension before the pushview action, can you analyze the current view by examing the view hierarchy?
Please check if you have any unnecessary codes like below in your BaseNavigationViewController :
func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRequireFailureOf otherGestureRecognizer: UIGestureRecognizer) -> Bool {
return true
}
Here I have a sample code which reproduces this issue (freezing app in pushing VC) that you have to reproduce it by these steps:
Try using the (left | right) edge pop gesture when there are no view controllers below it (i.e on root view controllers, your VC-Home controller)
Try clicking on any UI elements after this(which pushes you to next ViewController).
Sample Code: https://github.com/aliuncoBamilo/TestNavigationPushBug
My case solved by restarting Xcode and simulator, then choosing a different device from simulators list.
Answer by #Penkey Suresh! and #Tim Friedland helped me alot, one thing that i had to do extra for my usecase, might help someone else too.
USE CASE:
I had tab bar controller and i wanted swipe-back-gesture on screens let's say i'm on tabA and opened VC1, VC2 from there. My swipe gesture was working correctly on VC1 and VC2 but for some reason it was not disabling when coming back to tabA which is why it was freezing when trying to swipe left from there and trying to click somewhere (as mentioned by #Pankey Suresh)
SOLUTION IN SWIFT 5
I have this custom class implemented:
class BaseSwipeBack: UIViewController, UIGestureRecognizerDelegate {
func swipeToPop(enable: Bool) {
if enable && (navigationController?.viewControllers.count ?? 0 > 1){
self.navigationController?.interactivePopGestureRecognizer?.delegate = self
navigationController?.interactivePopGestureRecognizer?.isEnabled = true;
}
else {
self.navigationController?.interactivePopGestureRecognizer?.delegate = nil
navigationController?.interactivePopGestureRecognizer?.isEnabled = false;
}
}
}
USAGE
VC1 class - make it sub class of BaseSwipeBack that we just created so that you can access the functions
class VC1: BaseSwipeBack {
override func viewDidLoad() {
}
override func viewDidAppear(_ animated: Bool) {
self.swipeToPop(enable: true)
}
deinit {
self.swipeToPop(enable: false)
}
}
tabAController class - although i have disabled gesture in deiniting VC1 but it was not working fine so i had to disable it again tabAController
class tabAController: BaseSwipeBack {
override func viewDidLoad() {
}
override func viewDidAppear(_ animated: Bool) {
self.swipeToPop(enable: false)
}
}
I have a first tableViewController which opens up a second tableViewcontroller upon clicking a cell. The second view controller is presented modally (Show Detail segue) and is dismissed with:
self.dismissViewControllerAnimated(true, completion: {})
At this point, the second view controller slides away and reveals the first view controller underneath it. I would then like to reload the first view controller. I understand that this may require use of delegate functions, but not sure exactly how to implement it
Swift 5:
You can access the presenting ViewController (presentingViewController) property and use it to reload the table view when the view will disappear.
class: FirstViewController {
var tableView: UITableView
present(SecondViewController(), animated: true, completion: nil)
}
In your second view controller, you can in the viewWillDisappear method, add the following code:
class SecondViewController {
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
if let firstVC = presentingViewController as? FirstViewController {
DispatchQueue.main.async {
firstVC.tableView.reloadData()
}
}
}
}
When you dismiss the SecondViewController, the tableview of the FirstViewController will reload.
I solved it a bit differently since I don't want that dependancy.
And this approach is intended when you present a controller modally, since the presenting controller wont reload when you dismiss the presented.
Anyway solution!
Instead you make a Singleton (mediator)
protocol ModalTransitionListener {
func popoverDismissed()
}
class ModalTransitionMediator {
/* Singleton */
class var instance: ModalTransitionMediator {
struct Static {
static let instance: ModalTransitionMediator = ModalTransitionMediator()
}
return Static.instance
}
private var listener: ModalTransitionListener?
private init() {
}
func setListener(listener: ModalTransitionListener) {
self.listener = listener
}
func sendPopoverDismissed(modelChanged: Bool) {
listener?.popoverDismissed()
}
}
Have you Presenting controller implement the protocol like this:
class PresentingController: ModalTransitionListener {
//other code
func viewDidLoad() {
ModalTransitionMediator.instance.setListener(self)
}
//required delegate func
func popoverDismissed() {
self.navigationController?.dismissViewControllerAnimated(true, completion: nil)
yourTableViev.reloadData() (if you use tableview)
}
}
and finally in your PresentedViewController in your viewDid/WillDisappear func or custom func add:
ModalTransitionMediator.instance.sendPopoverDismissed(true)
You can simply reaload your data in viewDidAppear:, but that might cause the table to be refreshed unnecessarily in some cases.
A more flexible solution is to use protocols as you have correctly guessed.
Let's say the class name of your first tableViewController is Table1VC and the second one is Table2VC. You should define a protocol called Table2Delegate that will contain a single method such as table2WillDismissed.
protocol Table2Delegate {
func table2WillDismissed()
}
Then you should make your Table1VC instance conform to this protocol and reload your table within your implementation of the delegate method.
Of course in order for this to work, you should add a property to Table2VC that will hold the delegate:
weak var del: Table2Delegate?
and set its value to your Table1VC instance.
After you have set your delegate, just add a call to the delegate method right before calling the dismissViewControllerAnimated in your Table2VC instance.
del?.table2WillDismissed()
self.dismissViewControllerAnimated(true, completion: {})
This will give you precise control over when the table will get reloaded.