Toolbar incorrectly positioned during push animation with hidesBottomBarWhenPushed - ios

I have an App using a Tabbar for basic Navigation. From one of the screens of the Tabbar I want to enter another one that shows a toolbar instead of the Tabbar and a back navigation item on the top.
What is the best way to do this? If I use "Hide Bottom Bar on Push" (aka hidesBottomBarWhenPushed) and add a Toolbar to the screen I can see an animation removing the Tabbar before the Toolbar is placed at the bottom of the screen.

Solution for UITableViewController with toolbar (requires code)
Using code from this answer, I was able to achieve the same effect, but with the toolbar at the bottom of a table view.
Add this to your table view controller:
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];
[self.navigationController setToolbarHidden:NO animated:YES];
}
- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];
[self.navigationController setToolbarHidden:YES animated:YES];
}
Important note: placing these calls in viewWillAppear and viewWillDisappear instead of viewDidLoad makes this easier to handle, as it will work reliably even for multiple pushes and pops of the same view controller, and you won't have to clean up after it in the previous view controller.
And configure it like this in the storyboard:
Also, enable Hides bottom bar when pushed in the storyboard, or in your code, for the view controller being pushed.
Then you can add toolbar buttons to the toolbar in the storyboard.
Build and run, and you get this effect:
Here's a complete sample project demonstrating this.

Problem Example
Here is my solution,
In the first view controller that has the tabbar do this
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "someSegue" {
if let secondVC = segue.destinationViewController as? InfoTableViewController {
secondVC.hidesBottomBarWhenPushed = true
}
}
}
I also needed this, as my toolbar would re appear in the first VC.
override func viewWillAppear(animated: Bool) {
super.viewWillAppear(animated)
navigationController?.toolbarHidden = true
}
To stop the fade up animation of the toolbar, so its just there i used this in the second VC
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.toolbarHidden = false
}

Pure storyboard solution
If you're referring to the issue of the toolbar appearing above the tab bar during the push transition animation, I was able to fix this by adjusting the auto layout constraints on the toolbar in the storyboard (add it manually to your view controller; see my other answer if you're using a UITableViewController or UICollectionViewController and can't do this):
Add a constraint to set the distance to the bottom layout guide to zero:
Double click that constraint to edit it, and set the first item to Bottom (it will be Top by default).
All done! This will result in an effect like this:
Here's my sample project that demonstrates this working as expected. Note that I didn't change any of the code, everything is in the storyboard.

As of Xcode 7, the pure Storyboard solution doesn't work anymore because Xcode wouldn't let you assign the Bottom attribute to the Bottom Layout Guide anymore.
For my project, I used the following setup:
A UITabBarController as initial view controller, going into a
UINavigationController, with root vc set to...
UIRegularViewController, which should behave normally, but spawn a...
UISpecialViewController, which should hide the tab bar and instead display a toolbar. Also, it should hide the status bar, the navigation bar and the tool bar on tap.
Here is what I did to achieve this:
In the storyboard
UITabBarController: set Tab Bar Translucency to NO
UISpecialViewController: Set Simulated Metrics like so
Status Bar: None
Top Bar: Opaque Nav Bar
Bottom Bar: Opaque Toolbar
Set Extended Edges like this:
Under Top Bars: NO
Under Bottom Bars: YES
Under Opaque Bars: YES
Do not drag a UIToolBar into UISpecialViewController !
In the Implementations
// in UISpecialViewController.m
- (void)viewWillAppear:(BOOL)animated {
self.navigationController.toolbarHidden = NO;
self.navigationController.hidesBarsOnTap = YES;
}
- (void)viewWillDisappear:(BOOL)animated {
self.navigationController.toolbarHidden = YES;
self.navigationController.hidesBarsOnTap = NO;
}
- (BOOL)prefersStatusBarHidden {
return self.navigationController.navigationBarHidden;
}
Here is the Demo Code.
This is the result:

In fact, UIKit has already configured how Toolbar and Tabbar change in the page switching animation.
I also have this situation with you today, and the final solution surprised me.
For example, page A to page B, page A displays Tabbar, not Toolbar, page B does not display Toolbar, and does not display Tabbar.
At this time, B needs to set hidesBottomBarWhenPushed to true, which is necessary.
Then, in the declaration cycle of the two ViewControllers, in the viewWillDisappear of A and the viewWillAppear of B, if you set the navigation controller setToolbarHidden, this animation problem will occur.
If you set it in viewDidDisappear of A and viewDidAppear of B, the problem is solved. Although the toolbar will have a delayed animation, it is always better than the wrong animation.
Finally add:
The order of A and B life cycle function calls is:
A - viewWillDisappear
B - viewWillAppear
A - viewDidDisappear
B - viewDidAppear
These four methods are interleaved.

Using Xcode 12.4 iOS 14.4
for those who struggle with this issue and try solutions above with no luck.
let's say A is with tabBar only, B is only showing toolbar
remember to set hidesBottomBarWhenPushed = true in B's init
override init(nibName nibNameOrNil: String?, bundle nibBundleOrNil: Bundle?) {
super.init(nibName: nibNameOrNil, bundle: nibBundleOrNil)
hidesBottomBarWhenPushed = true
}
implement these below in B. (no need to do anything in A)
override func viewDidLoad() {
super.viewDidLoad()
navigationController?.setToolbarHidden(true, animated: false)
}
override func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
navigationController?.setToolbarHidden(false, animated: false)
}
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
navigationController?.setToolbarHidden(true, animated: true)
}
that's it!!
p.s. if you want to remove the toolbar animation from bottom up then add this
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
navigationController?.toolbar.layer.removeAnimation(forKey: "position")
}

Related

Accessibility set focus to navigation bar title item

Overview:
I would like to set the accessibility focus to the navigation bar's title item.
By default the focus is set from top left, meaning the back button would be on focus.
I would like the title item to be in focus.
Attempts made so far:
UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification,
navigationController?.navigationBar.items?.last)
Problem:
The above code makes no difference, the back button is still in focus.
Possible Cause:
Not able to get the item corresponding to the title to be able to set the focus.
Solution 1
I don't like it, but it was the minimum amount of hacking that does not rely on digging through hidden subviews (internal implementation of UINavigationBar view hierarchy).
First in viewWillAppear, I store a backup reference of the back button item,
and then remove the back button item (leftBarButtonItem):
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
backButtonBackup = self.navigationItem.leftBarButtonItem
self.navigationItem.leftBarButtonItem = nil
}
Then I restore the back item, but only after I dispatch the screen changed event in viewDidAppear() :
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification, nil)
DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) { [weak self] in
self?.navigationItem.leftBarButtonItem = self?.backButtonBackup
}
}
Solution 2:
Disable all accessibility on the nav bar and view controller up until viewDidAppear() is finished:
self.navigationController.navigationBar.accessibilityElementsHidden = true
self.view.accessibilityElementsHidden = true
, and then in viewDidAppear manually dispatching the layout element accessibility focused event to the label subview of UINavigationBar:
UIAccessibilityPostNotification( UIAccessibilityLayoutChangedNotification, self.navigationController.navigationBar.subviews[2].subviews[1])
// The label buried inside the nav bar. Not tested on all iOS versions.
// Alternately you can go digging for the label by checking class types.
// Then use DispatchAsync, to re-enable accessibility on the view and nav bar again...
I'm not a fan of this method either.
DispatchAsync delay in viewDidAppear seems to be needed in any case - and I think both solutions are still horrible.
I invoked UIAccessibilityScreenChangedNotification on navigation title from viewDidLoad and it worked
UIAccessibilityPostNotification(UIAccessibilityScreenChangedNotification,
self.navigationItem.title);
First, we'll need to create an useful extension:
extension UIViewController {
func setAccessibilityFocus(in view: UIView) {
UIAccessibility.post(notification: .screenChanged, argument: view)
}
}
Then, we'll be able to set our focus in the navigation bar title like this:
setAccessibilityFocus(in: self.navigationController!.navigationBar.subviews[2].subviews[1])

How to fix why status bar space behind ScrollView in Xcode?

I added a scroll view to my view which is hover the status bar (I hid it). The scroll view is working fine, but when I'm scrolling to the top, I have a white space which disappears when I tap on my screen, and appears again when I scroll down then top.
I noticed that the scroll bar is not going to the top of my view, but stopped at the status bar.
Here are screenshots which show you what I mean.
Here I'm at the top of my view but the scroll bar isn't:
Here is the same view with the white status bar which appears when I scroll top again:
It disappear when I tap on my screen or scroll down.
Here are my constraints:
I think it's a problem of Layout Margin or something like that, but I don't what I should change?
I hide the status bar like that in my view controller:
override func viewWillAppear(_ animated: Bool) {
UIApplication.shared.keyWindow?.windowLevel = UIWindowLevelStatusBar
super.viewWillAppear(animated)
}
EDIT: Even if I comment the line which hides the status bar, I still have the same problem with my scroll view. So the problem doesn't come from how I hide it.
As Sam said, I changed the content insets to "Never" on the scroll view and it works.
While unrelated to your question, I have to react to the way you hide the status bar - the proper way is to override prefersStatusBarHidden in your view controller and call self.setNeedsStatusBarAppearanceUpdate() in your viewWillAppear:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.setNeedsStatusBarAppearanceUpdate()
}
override var prefersStatusBarHidden: Bool {
return true
}
UPDATE
Since your view controller is inside of a UINavigationViewController, you need to override childViewControllerForStatusBarHidden in UINavigationViewController to use visibleViewController as the controller to determine status bar hidden (I added override to childViewControllerForStatusBarStyle for the consistence):
extension UINavigationController {
open override var childViewControllerForStatusBarStyle: UIViewController? {
return visibleViewController
}
open override var childViewControllerForStatusBarHidden: UIViewController? {
return visibleViewController
}
}

iOS 11 prefersLargeTitles not updating until scroll

I implemented a basic UIViewController with a UITableView that's wrapped in a UINavigationController. I set prefersLargeTitles to true:
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.title = "Coffees"
}
However, the title stays small until I scroll the view, at which point it enlarges. I tried moving that call to where I create the UINavigationController, but there was no effect. I am sure the navigationController is not nil when I set prefersLargeTitles.
Should I be updating that property elsewhere? Or should I file a Radar?
Update:
This only seems to happen if my view contains a UITableView or is itself a UITableViewController
I recently hit the same issue and none of the suggestions worked for me. Instead, all I needed to do was to invoke sizeToFit(). Sample code:
private func configureNavigator() {
guard let navigationController = navigationController else { return }
navigationController.navigationBar.prefersLargeTitles = true
navigationItem.largeTitleDisplayMode = .automatic
navigationController.navigationBar.sizeToFit()
}
I hope this helps!
For me the only working solution is:
DispatchQueue.main.async { [weak self] in
self?.navigationController?.navigationBar.sizeToFit()
}
in
viewWillAppear()
I had the same issue only on one tableview ...
I had to set :
self.tableView.contentInsetAdjustmentBehavior = .never
so that my tableview stop scrolling when uiviewcontroller was loaded.
It's the tableview automatic scrolling that makes the large title being hidden
Hope this helps
I had the same problem. Although you are not using Storyboards but I hope this could help someone. I checked "Prefer Large Titles" for the Navigation Controller (not the View Controller) I embedded my TableViewController in. All the View Controllers after the Navigation Controller turned and had large titles, and it should work.
Same issue with Swift 5.2
my view contains tableView and prefersLargeTitles is not updating until scroll, I fixed it by setting
self.tableView.contentInsetAdjustmentBehavior = .never
Modifying the contentInset of the tableView with top:1 will force the NavigationBar to expand and display the large titles.
Obj-C
-(void) viewWillAppear:(BOOL)animated {
if (#available(iOS 11.0, *)) {
tableView.contentInset = UIEdgeInsetsMake(1, 0, 0, 0);
}
}
Swift
override func viewWillAppear(_ animated: Bool) {
if #available(iOS 11.0, *) {
tableView.contentInset = UIEdgeInsetsMake(1, 0, 0, 0)
}
}
Note: If you have a tableView.reloadData() in your viewWillAppear make sure to call it after editing the contentInset
In my case the solution was to set tableView's top align to Safe Area and not Superview
I ran into the same issue and found that it’s usually best to set the prefersLargeTitles property from the view controller or object that sets it up, and to do so before it is presented.
For instance, if the view controller in question is shown upon app launch:
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
let window = UIWindow(frame: UIScreen.main.bounds)
let someViewController: UIViewController = CustomViewController()
let theNavController = UINavigationController(rootViewController: someViewController)
theNavController.navigationBar.prefersLargeTitles = true
window.rootViewController = theNavController
window.makeKeyAndVisible()
return true
}
or if presenting a particular view controller:
let someViewController: UIViewController = CustomViewController()
let theNavController = UINavigationController(rootViewController: someViewController)
theNavController.navigationBar.prefersLargeTitles = true
present(theNavController, animated: true, completion: nil)
I found this method to be a more sure-fire way to ensure that the navigation title is displayed accordingly. Hope this helps! :)
I have wasted some considerable amount of time on this as prefersLargeTitle saga works on some view controllers as expected and with some it produces the same issue above.
Solution for me was to uncheck Extended Edges Under Top Bars in IB - for those view controllers who show large title momentarily until the contents of the table view are loaded then navigation bar jumps back up to regular size. It only shows the large title when scrolling the table view down.
This is backward compatible with iOS 10 and does not leave any empty space above the first row in the table view.
I had checked prefersLargeTitle on the navigation controllers attributes inspector only in IB - nothing in code. Same for largeTitleDisplayMode = .always
As for why this happens with some view controllers and not others, I have absolutely no idea!
In the storyboard I set the Navigation Item's Large Title to Never.
In my ViewController's viewDidLoad method I set the following:
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.largeTitleDisplayMode = .always
Programmatically:
In AppDelegate.swift:
window = UIWindow(frame: UIScreen.main.bounds)
window?.makeKeyAndVisible()
let navigationController = UINavigationController.init(rootViewController: ViewController())
window?.rootViewController = navigationController
In ViewController:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.navigationBar.prefersLargeTitles = true
navigationItem.largeTitleDisplayMode = .automatic
}
override func loadView() {
super.loadView()
view.addSubview(tableView)
view.addSubview(loadingView)
NSLayoutConstraint.activate([
tableView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor),
tableView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
tableView.widthAnchor.constraint(equalTo: view.safeAreaLayoutGuide.widthAnchor),
tableView.heightAnchor.constraint(equalTo: view.safeAreaLayoutGuide.heightAnchor)
])
}
Make sure your tableView has beed previously added to your view.
I tried all of the other answers but what worked for me was to set the content offset of my UITableView to CGPoint(x: 0, y: -1) in viewDidLoad:
tableView.setContentOffset(CGPoint(x: 0, y: -1), animated: false)
I just had this same issue and, in my case, it turns out that the Storyboard structure that was working in iOS 10 with Swift 3 (and also works with iOS 11 with Swift 3) was causing the issue on iOS 11 with Swift 4.
To elaborate:
I had a regular UIViewController in my storyboard that I had set to a UINavigationController subclass (my hierarchy is similar to yours, with UITabBarController subclass → UINavigationController subclass → UITableViewController subclass).
In iOS 10, this worked fine.
In iOS 11, this also works fine when you run the existing Swift 3 app.
However, with the Swift 4 app, running on iOS 11, I was seeing the same symptoms you described (large titles only appear when you pull/scroll the view down).
To fix, I replaced the UIViewController-based elements in the Storyboard with actual UINavigationController instances (which contain a UINavigationBar explicitly in the Storyboard – I have a hunch this is where the crux of the issue stems from, as the UIViewController instances didn’t have that element explicitly declared within the Storyboard).
Anyway, that fixed the issue for me.
I’ll file radar as this looks like a Swift 4-based regression as, for me, it works both in iOS 10 with Swift 3 and in iOS 11 with Swift 3.
General changing the behaviour of the navigationBar should be done in viewWillAppear(_:)
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.navigationBar.prefersLargeTitles = true
}
After doing that it worked fine for me.
One more possible solution is to end refresh in your refreshHandler(). like this-
#objc func refreshPage() {
self.refreshControl?.endRefreshing() //End here
self.loadTableData() //Get fresh data and reload table
}
I solved this issue via storyboard
Navigation Controller -> Navigation Bar -> Attributes inspector -> Prefers Large Titles(Checked)
View Controller -> Navigation Item -> Attributes inspector -> Large Title (Automatic or Always checked)
I think It does seem a little bit dummy but I effectively solved the problem with this:
self.navigationItem.prompt = ""
self.navigationItem.prompt = nil
It's like navigationBar needs a sort of update in one of its elements to update the layout.
Sometimes to update something in navigationBar I need to hide and unhide it.. That's why I think there is a best way to do it.. For the moment that's my workaround.
I had a similar issue with navigation bar, but in my case it had a custom title view, and navigation bar remained empty until table view is scrolled down, which triggered UILayoutContainerView to layout its subviews, one of which are navigation controller's view and navigation bar. I assume the root of it is the same as the large title navigation bar issue.
Anchoring tableView to the safeAreaLayoutGuide didn't work out for me, largeTitleDisplayMode couldn't be other then .never
So I managed to fix it by calling self.navigationController?.view.setNeedsUpdateConstraints in the top presented controller's viewDidAppear(animated:) function, or scheduling this call for the next run loop in viewWillAppear(animated:), like:
DispatchQueue.main.async {
self.navigationController?.view.setNeedsUpdateConstraints()
}
In this case, navigation bar appeared with the correct content and size along with presenting transition, instead of popping in after transition was completed
What worked for me is setting the self.navigationController?.navigationBar.prefersLargeTitles = true before calling tableviews reload method.
The answers above for tableview also works for collection view if parent view not scrolled before navigation:
self.collectionView.contentInsetAdjustmentBehavior = .never
If parent view scrolled before navigation the solution above did not work in my case. I had to add the answer above as:
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
self.navigationController?.navigationBar.sizeToFit()
}
That does seem like a weird behavior at first, but try setting the navigationItem.largeTitleDisplayMode to always. The default is automatic - and it's not defined how that works in the docs.
Also wrote / will update an answer about large titles here.
I had the similar issue. The view is a table view. The property of prefersLargeTitles is set at viewDidLoad event. Then I set view's title in viewWillAppear event.
override open func viewDidLoad() {
if #available(iOS 11.0, *) {
self.navigationController?.navigationBar.prefersLargeTitles = true
} else {
// Fallback on earlier versions
}
...
}
override open func viewWillAppear(_ animated: Bool) {
self.navigationItem.title = "something"
...
}
In my prepare segue event, I set navigation item's tile to nil so that the next view left navigation var item displays "Back" automatically.
override func prepare(for segue: UIStoryboardSegue,
sender: Any?) {
self.navigationItem.title = nil
...
}
The first time the table view displays large title correctly. However, if I select a row to next view and back to the table view, the navigation item's title becomes empty.
After several hours' struggling, I finally find out that the view's title should be set in viewDidAppear event! It seems that whatever set to view's title in Will event would be reset by UIKit internally back to nil. So it has to be set in a different event.
override func viewDidAppear(_ animated: Bool) {
self.navigationItem.title = "something"
...
}
override open func viewWillAppear(_ animated: Bool) {
// self.navigationItem.title = "something" // Remove it and set title in Did event!
...
}
Before I introduced this iOS 11 new feature, my app runs OK. It seems that the new feature has some changes in UIKit so that the previous version app may need some updates/changes to make it work.
I had the same issue and fixed it by changing order of views in my ViewController in InterfaceBuilder.
It seems like if the first view in Hierarchy is NOT a ScrollView then NavigationBar appears in LargeTitle mode and does not animates together with scroll view. If you need to have Navigation Bar title to reflect your scroll then you need to put your scroll view as the first in view hierarchy.
Also, I am not completely sure in this but looks like Navigation Bar appearance in standard or Large Title mode depends on views hierarch of previous Controller.
Similar issue for me with a UITableViewController added to a UIViewController. In my instance, these view controllers are themselves embedded in a UITabBarController and only the first tab displayed correctly used a large title. Other tabs required a manual scroll before the large title was displayed.
The only thing I could get to work was adjusting the contentInset as per #pau-senabre's answer, except I the top inset wasn't helpful for me. Instead, I set the left inset and then reset it on the next runloop.
private var isFirstAppearance = true
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
if isFirstAppearance {
applyLargeTitlesFix()
}
}
private func applyLargeTitlesFix() {
let originalInset = tableViewController.tableView.contentInset
tableViewController.tableView.contentInset = UIEdgeInsets(top: 0, left: 1, bottom: 0, right: 0)
DispatchQueue.main.async { [weak self] in
self?.tableViewController.tableView.contentInset = originalInset
}
isFirstAppearance = false
}
Same issue here with Swift 4.2, iOS 12, and refactored Storyboards.
Tried adding prefersLargeTitles = true to viewWillAppear and viewDidLoad, but neither fixed my issue.
Instead, I copied the refactored storyboards back into main.storyboard and found the option to enable large titles in IB. Set that option, then refactored the storyboards back out and everything is working now. For some reason, the initial refactoring stripped out the option and I couldn't enable it programmatically.
I had the same issue (iOS 14, Xcode 12.2).
It only affected navigation controllers displaying table views.
I had originally set tableView.tableFooterView = UIView() to get rid of extra separators after the last cell. Setting the footer view to nil fixed the scrolled-up navigation title.
I had same issue.
I have set below code in viewdidload method. and it get fixed.
self.navigationController?.navigationBar.prefersLargeTitles = true
self.navigationItem.largeTitleDisplayMode = .never

Swift calling setNavigationBarHidden but view wont move to top

I am hiding my navigation bar when I scroll by calling: self.navigationController?.setNavigationBarHidden(true, animated: true)
The only problem is that the navbar doesnt get hidden all the way.
Whats even stranger is if I push to a new VC and go back and now try to scroll the navigation bar gets hidden all the way which is what I want.
If it matters I am hiding the navigation bar on VC2 then showing it when I exit back to VC 1.
This is what it looks when I try to hide the navbar first time, it doesnt go up all the way/underlying view showing too much.
If I push the to next VC and go back and now try to hide the navigationbar it works
The my view has a constraint of 0 to top layout so its hugging the top
So how can I make my view always be like in the second image when hiding my navigation bar?
Try this code...
Note: This is a simple approach for your problem. If you want more custom look navBar and status bar look .You should read my previous comment...
Set navigation controller property hidesBarsOnSwipe to true
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
navigationController?.hidesBarsOnSwipe = true
}
I understand your question.
The green part in your second image is not a navigation bar, it is a status bar.
You can hide the status bar as below.
You should implement prefersStatusBarHidden on your view controller(s):
In Swift 2:
override func prefersStatusBarHidden() -> Bool {
return true
}
In Swift 3:
override var prefersStatusBarHidden: Bool {
return true
}

hidesBottomBarWhenPushed not set when returning back to ViewController

I have the hidesBottomBarWhenPushed = true set for one of my UIViewController's (call it ViewControllerA) that is pushed onto my UINavigationController stack. I also opt to show the bottomBar when I push a new ViewController ontop of ViewControllerA. Therefore I have:
class ViewControllerA: UIViewController {
override func viewWillDisappear(animated: Bool) {
self.hidesBottomBarWhenPushed = false
}
override func viewWillAppear(animated: Bool) {
self.hidesBottomBarWhenPushed = true
}
This all works fine.
When I push ViewControllerA, the bottom bar hides.
When I push any other ViewController, the bottom bar shows.
However, when I am traveling backwards in the navigation stack (aka hitting the UIBarButtonItemBack button), I cannot get the bottomBar to hide when I pop the navigation stack to reveal ViewControllerA.
What am I missing? Thanks!
Got it! Here's what worked:
class ViewControllerCustom: UIViewController {
init() {
self.hidesBottomBarWhenPushed = true
}
override func viewDidAppear(animated: Bool) {
self.hidesBottomBarWhenPushed = false
}
}
And then in every UIViewController's custom implementation of BarButtonItemBack pressed I check to see if the previous view controller (that will be popped to needs to hide the tab bar). Granted I abstracted this out into a general function so I didn't need to repeat code, but here's the concept. Thanks for the help figuring this out though!
func barButtonItemBackPressed(button: UIButton) {
var viewControllers = self.navigationController!.viewControllers as! [UIViewController]
if ((viewControllers[viewControllers.count - 2]).isKindOfClass(ViewControllerCustom.self)) {
(viewControllers[viewControllers.count - 2] as! ViewControllerCustom).hidesBottomBarWhenPushed = true
}
self.navigationController?.popViewControllerAnimated(true)
}
I believe the intended use of this property is to hide the bar when pushed. So, when your view controller appears after the top-most one is popped, it wasn't pushed on the stack, so it doesn't change the tab bar's appearance.
This leaves you with two options:
1) Keep the bottom bar for all view controllers. When text is being entered, the keyboard covers the bottom bar.
2) Hide the bottom bar for View Controller A, as well as any other view controller that is pushed on top of A.

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