I have an application with 5 UIViewControllers each inside a corresponding UINavigationController, all tucked inside a UITabBarController that displays 5 tabs at the bottom of the screen.
I want to display another UIViewController (inside a UINavigationController) when a dialog button is pressed.
This view should only be loaded and unloaded programatically; i.e. it should not appear in the tab bar. However, I want the tab bar to be visible always.
If I add the [UINavigationController view] to [self window] the UITabBar is covered. If I add it to any other layer, the UINavigationController adds on the compensation it has for the status bar so appears further down than expected.
A solution would be to have the 6th UINavigationController added to the UITabBar with the others, but with its tabBarItem hidden. Then I can show it and hide it using the tabBars selectedIndex property.
Accessing the tabBarItem through the UIViewController shows no obvious way of doing this.
#wisequark, I think you completely misunderstood and you have almost rewritten the architecture of my application. However I have a separate navigation controller for each view as they are mutually exclusive and there is no concept of "drilling down".
#Kendall, This is what I expect I will have to do - have the modal view appear with a hide button to bring back the normal interface. But it would be nice to keep the tab bar always visible, so I was just wondering if anyone knew of a way.
It sounds as though you have a mess on your hands. A UINavigationController is a distinct object that is very different from a UITabBarController. In general, your application should have a tab controller, one of who's tab's loads a UINavigationController which in turn loads it's views - not that both maintain management over the different views. It is also improper to refer to the display of a UIViewController as such an object doesn't have a visual representation. In the case of a UINavigationController, the navigation controller object is responsible for displaying a navigation bar and a table view (in the most common case) and for managing the display of all the views in the navigation hierarchy. It itself has no corresponding representation on screen. Similarly, a UITabBarController presents a tab bar and is responsible for the loading and unloading of the views and/or view controllers attached to the tab buttons. If we were to present this as an image, it would look something like this -
alt text http://img.skitch.com/20081112-2sqp7q4wafa34te1ga337u4k8.png
Well, it sounds like what you really want to do is present a modal view with the tab bar still visible. You could add your view as a subview of the tab bar controller's view. The tab bar's view is, oddly enough, not the tab bar itself but rather a view containing the tab bar and the selected item's view.
Alternatively, you could try calling presentModalViewController:animated: with the selected tab (i.e. [tabBarController.selectedViewController presentModalViewController:animated:]) as the receiver instead of the tab bar. I seem to recall doing this once (quite by accident) and the tab bar remained visible.
One more thought: since each of your five view controllers is a UINavigationController, you could always pushViewController:animated: onto the selected view controller, then hide the back button. Your view will just appear without animation. But you'll need to remember to pop your view controller off the stack whenever the user switches to another tab. That might take a bit more work.
The best idea I could think of would be to either push a modal navigation controller for your view (which would hide the tab bar which you do not want), or to get the tab bar controller current selected view controller (really your navigation controller for a tab) and push your new view controller on there - and then pop that view when another tab is selected with a tab bar delegate.
It seems wierd to me to push the view onto random tabs though, if the view is created from a dialog that is modal, I don't see why the view itself should not also be modal and hide tabs.
Related
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.
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.
I would like to introduce in my app a View that will contains both navigation bar and a tab bar at the bottom. View contains a Table View with multiple entries and once user tap on a cell a push segue takes him to another view with details regarding the cell he has previously tapped. If he decides, user can go back to parent view by tapping on 'Back' button of the navigation bar on top. In addition to this, I would like my view to have a tab bar at the bottom with extra tools for the user. So, if he decides to check the 'Creator' of the app, he can by simply tap on 'Creator' TabBarItem at the bottom.
I would like to ask you what is the best way to achieve the above. I have already tried to use UITabBarController combined with UINavigationController. Didn't achieve what I was looking for because I would like the view with the table on it to be independent from the TabBarController and NOT a part of it (by part I mean by accessible through tabs).
Do you believe a UINavigationController view with UITabBarView would be a better choice?
UPDATE
What I mean by, "independent from the TabBarController and NOT a part of it":
Once the app loaded, I would like to see my main view (with table) contains Navigation Bar on top and Tab Bar at the bottom. However, I don't want to see the first tab of the Tab Bar selected because my main view will not be accessible through tabs of the Tab Bar but through Navigation Bar. If, for example, I am in Main view and tap on 1st tap, I would like to move to another view that will contains some other info.
Option 1:-
Create a tab bar Controller and on that TabbarController assign your navigation Views.
say nav1 with tab1 , nav2 with tab2...
Option 2:-
Create a Navigation View Controller and than add the tabbarcontroller on that navigationView Controller by using addSubView.
So when the user clicks on a row in a table u will go to a different View which doesn't have the TabbarController and when the user comes back he will again see the TabbarController.
This is what I will do:
First I will subclass UITabbarController and create for example ParentTabBarController. This controller will contain all the tabs necessary and what they will do if they are clicked so on.
Next for each viewcontroller I create, I will subclass from this ParentTabBarController so that the tabs are already in. You can add additional functionality or override it depending on your situation.
In your appdelegate pass in a navigation controller and every time push and dismiss the viewcontrollers you created in second step.
Hope this helps..
I am developing an app that consists of a Tab Bar Controller that points to 3 view controllers (all with tabs). In one of these tab views I've made a button and I want it to open a new view (without a tab at the bottom). This new view would need a navigation bar with a back button to return to the previous view, so I was thinking I need to create a navigation controller?
Essentially this is what I'm trying to do (I apologize for the poorly drawn diagram).
How can I get this new view (entirely independent of the tab bar controller) to display programatically? Would this require a navigation controller?
You are describing a presented view controller. Call presentViewController:animated:completion:.
I very frequently do this with a navigation bar and a Back or Done button, just as you describe. But it's not a navigation controller or navigation interface; it's just a convenient way of showing the user how to get back.
For example, this is a presented view in one of my apps. The top is a navigation bar, and the cancel button gets us back (call dismissViewController...). The rest is a scrolling view (a UICollectionView) of buttons.
[myTabBar setSelectedIndex:1]
You may have to access the tabBar like self.tabBarController so… [self.tabBarController setSelectedIndex:1];
1 is index 1 in the tabbar's stack (this is like tapping a tabBar button manually)
My app has two distincts modes. There's a tab bar controller in the app delegate. There are two tabs, both using subclassed view controllers. The two view controllers essentially contain a nav controller each. The nav controllers have their root view controller, and normally when changing screens, I just push and pop controllers of the respective nav controller. This has the (normal) effect that the bottom tab bar is always visible, all great and sound.
This one time I'd like to present a screen modally however, so that the user can't do anything else than confirm or cancel the page using two buttons, ie I want to hide also the bottom tab bar. This would be a case for presenting the view modally I thought, but the view is presented within the nav controller bounds it seems, so the bottom tab bar is still visible, and this causes confusion in navigation the app. I'm not sure how it's possible that the modally presented view is not hiding the tab bar. Most of the questions around here seem to have the problem the other way around (wanting to (incorrectly) present a modal view and leave the tab bar visible).
These are my attempts:
[self presentModalViewController:controller animated:YES]; // inside tab bar controller :-(
[self.tabBarController presentModalViewController:controller animated:YES]; // nothing is displayed. The new controller is instantly deallocated.
[self.navigationController presentModalViewController:controller animated:YES]; // inside tab bar controller :-(
Investigating this, the self.tabBarController is actually nil. There seems to be no link back to the tab bar controller... I guess, to display modally on top of the tab bar, I need to get a link to that tab bar controller?
I seem to have found a solution, I'm not sure it's kosher, because somehow I wasn't able to use the self.tabBarController pointer of the view controller in which I start the view controller call.
What I did was reach for the app delegate, the app delegate having the tab bar controller defined as a public property. I could use that tab bar controller property to modally display my view controller over everything on the screen.