If I have the storyboard in the form of (where the arrows are segues)
UINavigationController -> ViewControllerA -> ViewControllerB
Would that be basically more or less equivalent to
ViewControllerA -> ViewControllerB
(NavigationBar) (NavigationBar)
if I manually wire each NavigationBar up to Button Bar Items with event listeners attached to unwind segues?
Or does UINavigationController offer something more than that?
UINavigationController is what is known as a container view-controller: it takes a bunch of other view-controllers and manages how their views are presented on the screen. UISplitViewController is another example of a container view-controller.
In the case of UINC, it:
Allows pushing a new "top" controller, animating it with a left-to-right/right-to-left animation depending on locale
Remembers the stack of previous top controllers, allowing you to pop back to them
Adds a UINavigationBar view above the top controller's view so the user can pop back by themselves (you can disable this)
Sets a layoutMargin on the top controller's view, so it can adjust content to not underlap the bar
Provides an edge-swipe gesture so the user can interactively pop to previous controllers (slowly peel the top sheet back)
For more information, including about how to create your own container view-controllers, see Apple's documentation on the subject: https://developer.apple.com/library/content/featuredarticles/ViewControllerPGforiPhoneOS/ImplementingaContainerViewController.html
There are some differences.
One that I have noticed, a UINavigationController will handle correctly putting the navigation bar in the right place for iPhone X vs other models (It will make the height larger so it goes into the wedge of the of screen, while just a nav bar will remain its standard height).
If you just put a nav bar on each UIViewController, you are going to have to check on each view controller if you need to update the bar size.
Basically the navigationController provides you many thing that you might use: A stack of UIViewControllers, a navigation bar, a toolbar, delegate methods, show/pop animations, etc. Doing all that by hand will be not too appropriate and a little bit messy. I suggest you to take a look to the Apple’s documentation for UINavigationController. There you will get a much better understanding of all the capabilities and methods that this class provides you.
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 a requirement to implement an app that has a navigation bar like bar at the top of numerous screens.
It has an icon on the left, some text, and some buttons on the right thus these would map well to a navigation item's left bar button items, title view, and right bar button icons.
However on most of the screens the content of the bar remains the same - i.e. a back button and title change would only appear occasionally for some screens, and on others the navigation bar would be present but is not actually used for navigational purposes.
Is the best of implementing this to configure a UINavigationItem, if so as there are multiple screens and multiple view controllers is there anyway the same UINavigationItem can be shared? That way I can configure the UINavigationItem in the RVC and keep it there as different view controllers get pushed, replacing it where need be when a back button does actually need to appear?
If this isn't the best approach then what alternatives are there? I experimented with making my RVC a container view controller and adding the bar as a view of that, that works for the immediate child view controllers but not for grandchild view controllers (which would take up the entire screen and not the portion alloted to them by the container view).
The navigationItem in UIViewController is readonly, so you can't have a single shared UINavigationItem shared between view controllers. You could have a base view controller class that manages setting the navigation item that you derive all of your view controllers from. To keep your classes from getting too coupled you could have it update the contents of the navigationItem from a NSNotification. Then you can just post a notification when you need all of the navigation items to be updated.
I am a newbie to IOS programming and currently i have a tab bar application with two tabs. I have two questions.
The first tab shows a map, imagine it with some pushpins. There is a button on the navigation bar and when this is clicked i want the map view to to move out and a list view to come in. You can see the UI from the image. The button is called list.
Now when i click list I want this view to go away and the list view to come in. So here are my questions ?
1) How do i do this ? I tried the navigation model but i don't want that because I do not want a back button. I tried to make two different views and just dragged the button to that view but the app crashes. I just want the list button on the nab bar and when clicked the view changes to the list view and the button text changes to map. So now if I click the button again it should go back to the map view and the button changes to list.
2) How do i achieve the animations for this ? Ive seen some app where the page flips around and I've seen some options like reducing the opacity etc but I want to achieve the flip animation.
Thank You for any help I get. I really appreciate it.
Interface Builder can do most of this. Hold down the control key and drag from your map View Controller's UIBarButtonItem titled "List" to your list View Controller, then choose the Action Segue "modal". An arrow appears representing the segue; click on it and use the Attributes Inspector to change the Transition to "Flip Horizontal". Here's a video
Or, you could do this programmatically with presentViewController:animated:completion.
Now to get back to the map from the list, I believe that must be done programatically. Create a method that calls dismissViewControllerAnimated:completion: and make your list View Controller's UIBarButtonItem titled "Map" trigger it.
After reading your comments, I am wondering... if the structure of your app is logically a tabbed app structure (as indeed you refer to it as a 'tab bar application'), shouldn't you consider using the UITabViewController instead of a NavigationController? That is what it is designed to do, after all.
If you do use a TabViewController you should reconsider your desire for flip animation, as that doesn't really make UI-sense for tabs. If you can dispense with the flip animation, TabViewController could be a good way to go and you should at least experiment with that before dismissing the idea. It is also designed to grow... you can incorporate any number of tabs in a tab bar. Check out the apple docs (with pictures!)
You will notice that tabs are at the foot of the screen, whereas your 'tab' navController buttons are in a navbar at the top of the screen. This also helps as your app grows, as it is straightforward - from a UI design point of view and programmatically - to incorporate navControllers as navigation tools within individual tabs. For example, if your map/list flip routine does indeed make sense for this part of you app, you can keep this as a single tab (in it's own navigationController) and add other tabs for other parts of the app...
update
From your comment, you are saying that you are interested in the navController-inside-tabBarController setup. In this case here are some ways to get flip transitions AND no back button..
(1) modal presentation
The easiest way to get what you want is to set up one of your viewControllers (say the map view) to present the other one (the list view) modally.
If in the storyboard:
embed your mapViewController in a navController with a navbar button for navigation to the listView as in your picture
add your listViewController to the storyboard and embed it in it's own navContoller (not the mapViewController's navController). Drag a barButtonItem to this navController and wire it up to an IBAction in listViewController
CTRL-drag from mapViewController's 'list' button to the listViewController to create a segue. Select the segue and in the attributes inspector set the segue type to 'modal', with transition 'flips horizontal' and 'animated' checked. Give it a name in case you want to refer to it in code.
in the listViewController's IBAction add this:
[[self presentingViewController] dismissViewControllerAnimated:YES completion:nil];
That should achieve your result. You can use the completion block to send information back from the list view to the map view, and/or set the map view as the listView's delegate.
If you are not using the storyboard check this apple guide
Presenting View Controllers from Other View Controllers
especially "Presenting a View Controller and Choosing a Transition Style".
There is one catch with this approach - when the presented view flips onto the screen, the entire previous view, including the tab bar, is flipped out of the way. The idea is that this is a modal view which the user is required to dismiss before doing anything else in the app.
(2) push/pop in a single navController If this does not suit your intent, you can navigate using a single NavigationController with push and popping of views, and you can hide the back button ... but you really would need to keep the back button functionality as you do want to go back to the mapView, not on to a new map view.
To hide the back button try:
self.navigationItem.hidesBackButton = YES
in the uppermost viewControllers' viewDidLoad
Then you can add a barButtonItem in the xib/storyboard, with this kind of IBAction:
[self popViewControllerAnimated:NO]
or
[self popToRootViewControllerAnimated:NO]
You would have to construct the flip animation in code as it is not supported as a built-in with UINavigationController (best left as an exercise for the reader!)
(3) swapping views in a single viewController As ghettopia has suggested, you could use a single viewController inside a navController (or with a manually place navBar) and swap two views around using the UIView class methods
transitionFromView:toView:duration:options:animations:completion
transitionWithView:duration:options:animations:completion.
This could be a good simplifying solution as your list and map are essentially two views of the same data model.
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.