How can we attach a view to a UITabBar or UITabBarController and allow it to conform to things like "Hide bottom bar on push"? Any view that gets added to the UITabBarController will a part of the UINavigationController, meaning that the view will not take part in the tab bar animation, and will simply be left visible after a push.
Is it frowned upon to subclass UITabBar itself, and if not, how would we handle the subviews of it? My attachment is located behind the tab bar and becomes visible when needed (like Spotify's or Apple Music's player bar), which causes problems when iOS automatically moves the z-index of the tab bar during these situations.
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I am trying to 3D peek and pop items in a UITableView. Everything works fine, except the target ViewController has a UINavigationBar which also shows.
I added my UINavigationBar to my ViewController code through Interface Builder and set self.navBar.isHidden to true which hides the UINavigationBar, but it leaves empty space equal to the size of the UINavigationBar.
Does anyone know how to hide the UINavigationBar properly?
Note: I am not using a UINavigationController, I simply added the UINavigationBar to my ViewController by drag/drop.
the target ViewController has a UINavigationBar which also shows
Use a real UINavigationController plus UITableViewController (as its root view controller). This is an excellent way to have a navigation bar even if you never intend doing any navigation.
Here's a big advantage of doing that: You don't even need to hide the navigation bar when you peek! Use the UITableViewController alone as the peek navigation controller, and the UINavigationController when you pop. Thus, the preview won't have any navigation bar but if the user presses all the way and you do the real transition, the new view controller will have the navigation bar. Remember, no law says that the peek view controller must be the same as the pop view controller!
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.
In Apple's recently released Remote app I noticed the way in which the navigation bar behaves is unique and I haven't been able reproduce it. When popping the Now Playing view controller the navigation bar remains transparent for the Now Playing view controller and the navigation bar for the library view controller also stays translucent (Screenshot 1). I'm trying to figure out if they are using two navigation controllers or only one. Personally I feel they're using just one for two reasons (1) the interactive pop gesture is enabled; (2) when you press the 'Now Playing' button in the library view controller, just before the now playing screen has finished 'push view controller' animation the navigation bar becomes transparent (Screenshot 2). This is the behaviour I experience when pushing my view controller (which sets the navigation bar to transparent). So my question is: How does Apple present both navigation bars of the two view controllers as if they were individual (as with Screenshot 1), even the bar buttons, navigation title etc... are 100% in opacity when switching (usually when pushing/popping the buttons and titles of the previous view controller fade as the new controller is being pushed). I've tried playing around with the bar tint colour in viewDidAppear and viewWillAppear in both view controllers but cannot reproduce the same behaviour, and cannot prevent the bar buttons from fading.
Gosh I hope I've explained this well, I get confused just thinking about it!
Screenshot 1 (Popping):
Screenshot 2 (Pushing):
I just downloaded the application to make sure. Two different navigation bars are used. You can see this by using the interactive pop gesture. Notice how the navigation bar on the bottom view controller slides in and out. During normal push and pop transitions, the navigation items just fade in and out on the existing bar, while the bar is stationary. This is what happens up until the point where the now playing view controller is pushed.
If you look quickly, during the now playing view controller animation, you can see the bottom navigation bar disappear.
From my experience with UIKit behavior and what I see in the app, here is what I think happens:
album_vc = the bottom, list view controller
nowplaying_vc = the top view controller
On nowplaying_vc's viewWillAppear:
Set the navigation bar to hidden using [self.navigationController setNavigationBarHidden:YES animated:YES];. Since this is in animation block, this will make the navigation bar slide out during the push animation.
Set [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleLightContent; Pretty sure about this, because notice there is no animation in the transition of the status bar styles. It just becomes white.
On nowplaying_vc's viewWillDisappear:
Set the navigation bar to shown using [self.navigationController setNavigationBarHidden:NO animated:YES];. Since this is in animation block, this will make the navigation bar slide in during the pop animation.
Set [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleDefault; Again, notice how during interactive pop gesture, the status bar just changes with no animation.
To achieve the transparent look of the navigation bar of nowplaying_vc, you can use an empty image ([UIImage alloc]) with setBackgroundImage:forBarPosition:barMetrics:.
Since the application does not rotate, we can't be sure if the navigation bar on nowplaying_vc is part of another navigation controller or just a navigation bar on the top with a position of UIBarPositionTopAttached. For all we know, there isn't even a navigation bar there but just a back chevron image view (back bar button is comprised of an image view and a button).
I think the status bar style is changed in viewWillAppear: and viewWillDisappear: due to the unnatural feel there is during interactive pop gesture. I would recommend using an animated transition, or even better, use the new view controller-based status bar style, which the system animates transitions by itself.
Update for modern API:
You should use the animateAlongsideTransition:completion: or animateAlongsideTransitionInView:animation:completion: API, rather than relying on the implicit animations of viewWillAppear: and viewWillDisappear:.
Instead of hiding and showing the navigation bar, you can update the alpha for the navigation bar. It will animate smoothly during the transition. For the view controller with transparent nav bar, instead of modifying the nav bar, create a navbar (or just the back button and title etc.) manually in the second controller's view. We will then hide the navbar when transitioning from first view controller to the second one.
On your first controller's viewWillDisappear and on your second view controller's viewWillAppear:, set the navigation bar alpha to zero using self.navigationController.navigationBar.alpha = 0;. Since this is in animation block, this will make the navigation bar disappear during the push animation.
Set the alpha back to one in first controller's viewWillAppear and second controller viewWillDisappear.
I read several answers to this question but couldn't figure out how to do it. I'm using Xcode 4.2 with ARC and no storyboards.
I'm developing an app based on the TabBar application template and extended it to contain 4 UITabBars. I'm not using UINavigationController but instead using UINavigationBar next to the status bar. When the app is loaded with the first tab shown, I have a button on the UINavigationBar and when I press it, I want to hide the UITabBar and instead show the UIToolBar at the same location where the UITabBar was located.
I tried to hide and show using the hidden property (hiding the UITabBar and showing UIToolBar). What happens is the UITabBar is hidden but the UIToolBar is shown above the location where the UITabBar was shown before. This looks ugly and I want it to be shown at the very bottom of the screen.
I think I can't use hidesBottomBarWhenPushed as I don't use a UINavigationController but instead using Navigation bar directly.
Also, I want to revert back to showing the UITabBar and hide the UIToolBar when pressing the same button on the UINavigationBar.
I am not sure if my idea would work for your scenario. Here it is...
but before, just let me tell you that hiding UITabBar, unlike hiding UINavigationBar is not animated. So to me, hiding tabBar is not a user-friendly approach, unless you create your own subclass of UITabBarController that animates hiding the UITabBar.
You can use presentModalViewController:animated and dismissModalViewControllerAnimated: methods. The viewController that is being shown modally can have a UINavigationBar, it pops out from the bottom of the screen and covers the UITabBar with animation.
Hope that helps.
http://developer.apple.com/library/ios/#documentation/uikit/reference/UIViewController_Class/Reference/Reference.html
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.