Let's say I have 4 items in my UITabBar: A B C D.
Via the delegate methods, D pushes a new viewController from the UITabBar's navigationController, (removing the tabBar for that one view).
This works fine, but how can I keep the UITabBar from showing a blank view for D when going back from the new view?
I tried setting the selectedIndex to the previous index on push, but that just hangs the app (seems to work fine for modals, just not when pushing.)
If I interpret this correctly, when you're pushing a view as a result of selecting a tab, you're simultaneously changing the tab that's selected. This is probably trying to then change the view hierarchy that you're currently pushing a view on (that would be the result of selecting the other tab that you're trying to set it to). So it's probably crashing because it's replacing a view that's in the process of being displayed.
Also, from the sound of it you're using a UITabBarController inside of a UINavigationController. Apple says that you're not supposed to place a UITabBarController inside another view controller. The following is taken from Apple's docs on UITabBarController:
When deploying a tab bar interface, you must install this view as the root of your window. Unlike other view controllers, a tab bar interface should never be installed as a child of another view controller.
If this is the case, you should redesign your app so that you're not containing the tab bar controller in any other view controllers, or your app may behave oddly or stop working at some point.
If you wanted to make things behave exactly how you want them to, you could use a UITabBar directly, and implement your own UITabBarDelegate.
Related
I have a simple Navigation View Hierarchy that has 2 views it goes between. I wanted a customized navigation bar, so I have the default one hidden, and I've implemented a Container View which is shared between the 2 views in the nav hierarchy.
Everything works as I want it to, except when I segue to the lower or higher view the top bar appears slides away and reappears on the new view. I would like it to appear stationary when I push or pop to other views in the hierarchy.
Is there an easy way to do this? Or should I delete my custom shared Container View and try to make this work with the Navigation Bar (which I have currently "hidden")?
I had to do this for a client once. The way we did it was, like you said, make an encompassing view controller that housed a container view. Within this container view, we embedded a UINavigationController and would manually pop and push UIViewControllers to its navigation stack. Of course you want to hide the UINavigationController's nav bar.
It sounds like you sort of implemented this, but instead you just embedded a plain old view controller inside your custom navigation controller, and then segue to another view controller that is also embedded in the custom view controller? Ideally you want one instance of this custom nav controller with an embedded UINavigationController. I believe you will have to do all the view controller transitions programmatically.
Opinion: Personally, I would recommend against doing this. I believe that an app should feel like an extension of the OS it's on. A user should feel it's a part of their phone. Using the native navigation bar also decreases the level of effort a user is required to put forth to understand your app.
I know you're thinking "but it's just a nav bar" but we're talking about the same people that will potentially uninstall an app if it takes longer than 2.5s to load.
I wanted a customized navigation bar, so I have the default one hidden
That's your mistake. The way to get a customized navigation bar in a UINavigationController interface is to initialize it with init(navigationBarClass:toolbarClass:). Now the built-in navigation controller is using your navigation bar! And from there on, all will be well.
https://developer.apple.com/reference/uikit/uinavigationcontroller/1621866-init
I'm trying to create a tabbed application with navigation elements inside the tab bar, as seen in the picture below (the red bar) using Swift/XCode 6.2. Basically those three icons in the middle will direct the user to different view controllers. The other two icons would be context-based. For example, on a table view page you would see the menu icon and add new icon as seen in the image. However, clicking on a row would change the menu icon to a back icon, and the add icon to something else.
That's the general idea, but I'm having a very hard time implementing something even close to this. The first issue is that whenever I embed a view in a Tab Bar Controller, I can't move the tab bar to the top. However, when I create a custom UITabView in a View Controller, Control + Click and dragging a Tab Bar Item to another view doesn't create a segue. I haven't even begun to tackle having the navigation elements inside the bar.
I guess what I'm asking is just for a little guidance on what route to take to tackle this. I'm assuming I can't use a Tab Bar Controller or Navigation Controller because it doesn't seem like I can customize them all that much. So custom Tab Bar and Navigation Bars, and then implemnt the segues and button changes programmatically?
Thanks.
I will try to guide you from an architectural perspective (so you won't find much code below).
Using a UITabBarController
In order to achieve what you are suggesting, you are right you cannot use a UITabBarController straight away, among several reasons, the most immediate one is that they are meant to be always at the bottom and you want it in top (check Apple's docs). The good news is that probably you don't need it!
Note: If you still want to go with a UITabBarController for whatever reason, please see #Matt's answer.
Using a UINavigationController
You can use a UINavigationController to solve this task, since the UINavigationBar of a UINavigationController can be customized. There are multiple ways on how you can organize your view's hierarchy to achieve what you propose, but let me elaborate one option:
To customize a UINavigationBar's to add buttons, you just need to set its navigationItem's title view:
// Assuming viewWithTopButtons is a view containing the 3 top buttons
self.navigationItem.titleView = viewWithTopButtons
To add the burger menu functionality on a UINavigationController you can find several posts on how to do it and infinite frameworks you can use. Check this other SO Question for a more detailed answer (e.g. MMDrawerController, ECSlidingViewController to mention a couple).
About organizing your view hierarchy, it really depends on if when the user taps one of the main top buttons, it will always go to the first view controller in the new section or if you want to bring him back to the last view in the section where he was.
3.1 Switching sections displays the first view of the new section
Your app's UIWindow will have a single UINavigationController on top of the hierarchy. Then each of the 3 top buttons, when tapped, will change the root view controller of the UINavigationController.
Then, when the user changes section, the current navigation hierarchy is discarded by setting the new section view controller as the UINavigationController root view controller.
self.navigationController = [sectionFirstViewController]
3.2 Switching sections displays the last displayed view in the new section
This will require a slightly modified version of the above, where your each of your sections will have its own UINavigationController, so you can always keep a navigation hierarchy per section.
Then, when the user taps one of the top buttons to switch section, instead of changing as previously described, you will change the UIWindowroot view controller to the new section's UINavigationController.
window.rootViewController = sectionNavigationController
Using a custom implementation
Of course, the last and also very valid option would be that you implement yourself your own component to achieve your requirements. This is probably the option requiring the biggest effort in exchange of the highest customizability.
Choosing this option is definitely not recommend to less experienced developers.
I'd like to take a stab at this--I think it is possible to use a tab bar controller here.
Your topmost-level view controller will be a UITabBarController with a hidden UITabBar.
Each tab is contained in a UINavigationController.
All view controllers in the navigation controller will be a subclass of a view controller (say, SwitchableViewController).
In SwitchableViewController's viewDidLoad, you set the navigation item's title view (i.e. whatever's at the center; self.navigationItem.titleView) to be the view that holds the three center buttons. Could be a UISegmentedControl, or a custom view.
Whenever you tap on any of the buttons, you change the topmost UITabBarController's selected index to the view controller you want to show.
Issues you may encounter:
Table views inside tabs will have a scrollIndicatorOffset at the bottom even if the tab bar is hidden.
Solution: Play around with the automaticallyAdjustsScrollViewInsets of the tab bar controller, or the inner view controller. https://stackoverflow.com/a/29264073/855680
Your title view will be animated every time you push a new view controller in the navigation stack.
Solution: Take a look at creating a custom transition animation for the UINavigationController.
I have an app which has a login screen and when the user logs in, a tab bar controller is pushed. I currently have some views that would benefit from the fact that apple now allows using the split view controller in all iOS devices, so I was preparing to implement this when I read that the UISplitViewController must always be the root view controller. So I was wondering if it is possible to make the view in one of the tabs become a master-detail view using a UISplitViewController or will I need to implement this manually?
In case it is not possible to show the split view as a tab, could it be pushed from the tab bar controller? (e.g. the user taps a row in a table view and the master-detail view appears).
UISplitViewController in iOS 14 gained new API including a new column style that behaves differently from the unspecified style which is the "classic" interface. Using the modern column-style API, if you try to embed a UISplitViewController in a UITabBarController, it may not behave as you'd expect. For example, at least as of iOS 15, only the secondary view controller may be visible when you'd expect the primary and secondary be shown side-by-side. The documentation does note the following:
When you build your app’s user interface, the split view controller is typically the root view controller of your app’s window. ... Although it’s possible to install a split view controller as a child in some other container view controllers, doing so is not recommended in most cases.
I have however shipped multiple apps that put a split view controller in a tab bar controller using that classic API (via storyboard and programmatically), and they continue to work as of iOS 15. But it may be wise to move away from this as it's seemingly not an officially supported configuration.
Original answer pre-iOS 14:
You can definitely embed a UISplitViewController inside a UITabBarController. I've done just that for an app I released on the App Store. It has 3 tabs and each one is a split view controller.
Just drag out a tab bar controller into your Storyboard, delete the two controllers it added, then drag out a split view controller. Control drag from the tab bar controller to the split view controller and select the "view controllers" relationship segue.
On Xcode versions less than Xcode 8, you may see black or white bars at the top and bottom of the split view controller in the Interface Builder canvas, but these will not appear when the app is run on a device.
Here is the app running to show the split view embedded inside the tab bar controller on iPhone 6s Plus:
When you put a UISplitViewController inside a UITabBarController and the tab bar is set to be opaque you have an issue where your UISplitViewController content is shifted up the size of the tab bar:
To fix this issue you have to check the Under Opaque Bars checkbox on your UISplitViewController in your storyboard:
And now the UISplitViewController view size is correctly computed:
There is also a problem using this approach in iPhone (>IOS8) where the splitviewcontroller is in collapsed mode. When we push the list view to the details view we cannot hide the tabbarcontroller using the conventional "hidesBottomBarWhenPushed". So I have added the TabBarcontroller as root viewcontroller of a navigationcontroller. Now when I push to details view, I send the message to the root navigation controller and push the view to the details view instance in collapsed mode whereas in regular mode I just push it using showDetailsViewController()
For me, this worked.
XCode 13.2.1
iOS 15.2
splitViewController.extendedLayoutIncludesOpaqueBars = true
i'm curious about what's the best way to plan the controllers for my app.
i want my main screen to have 3 button.
1) should open a nav controller with details view
2) should open a controller with other buttons that lead to others controllers
3) should open a tab bar with 2 pages ( or eventually use a switch to change page instead of the tab bar)
this is the schema of what i want
http://i59.tinypic.com/2rrvrd4.png
Is it a correct schema or i should use my controllers differently? will apple reject an apple with such schema?
thanks
As #Fogmeister pointed out in the comments, going for a UITabBarController as the main interface for your app actually seems to be a more appropriate solution here.
However, you can go with the interface that you described, but then you should keep in mind that with your current setup, you are not only using UINavigationController in the first case, but your whole navigation system is still built upon UINavigationController in the following way:
Your app has one instance of UINavigationController.
Your initial UIViewController (the one with the three buttons), is the rootViewController of your UINavigationController.
You can navigate to the other view controllers using [self.navigationController pushViewController:newViewController] (or performSegue if you prefer using Storyboards).
In the case of your third view controller, you are pushing a UITabBarController onto the navigation controller's view controller stack, this UITabBarController needs to be initialized with the two view controllers that it is going to display before it gets pushed onto the stack.
My app is based around a UINavigationController. On some screens I have a UITabBarController embedded within. When I go to a screen with the tab bar everything works fine on the first tab. (each tab is a UITableViewController) I can tap a cell of the table view and it'll take me to the next page by correctly pushing it onto my nav controller. If I go to another tab it loads the table view fine, but if I tap a cell to take me to another view I get this error:
Nested push animation can result in corrupted navigation bar
Finishing up a navigation transition in an unexpected state. Navigation Bar subview tree might get corrupted.
It pushes on the next page, but then if I attempt to press the back button on the nav bar the app will crash.
How could I go about fixing this? I looked at multiple other responses to similar problems, but none of them have helped me with this.
It would be really helpful if you share your code.
However this may be helpful for you:
while using tab bar , you should try that every single tab has its own navigation controller and use individual navigation controller to move to specific viewcontrller of specific tab. I know its hard to understand like this..
For e.g in app del you have your main navigation controller using which you push to next view controller ,say "SecondViewController".
Now this second one has got one tab bar with 4 tabs tab1,tab2,tab3,tab4. now each tab can have any no of view controllers associated with them. For e.g on tab1,you move to another screen and again from there to next screen and so on.
So to manage them there should be separate navigation controllers like,tab1nav,tab2nav,tab3nav,tab4nav.
tabBarController.viewControllers = [NSArray arrayWithObjects:"tab1nav".....and so on all nav, nil];
Now depending in which tab you are, use that tab's navigation controller to move to next screen of that tab or move back.
If you have viewDidAppear function,
Remember to put [super viewDidAppear:animated]; inside the function.