I have an app which goes through a set of screens within a navigation controller, then there is a screen with a tab controller, which one of the contained views wants to display a modal view controller that should be displayed over the top of the whole app (not full screen though).
It's all working fine, but the modal window is partially covered at the top by the navigation controller. I've tried using self / self.tabBarController / self.navigationController / self.tabBarController.navigationController to call presentModalViewController but they either don't work or still display the modal window underneath.
I've been searching for an answer to this all day, everyone else seems to have problems when it DOES overlap, not when it doesn't.
Any ideas? Thanks. (code, screenshots & video below)
- (IBAction)add:(id)sender {
// create the view
AddAttainmentController *addScreen = [[AddAttainmentController alloc] init];
// pass in a selected pupil
[addScreen setPupils:[NSMutableArray arrayWithObject:pupil]];
// add the view to a navigation controller
UINavigationController *control = [[UINavigationController alloc] initWithRootViewController:addScreen];
// place the navigation controller on the screen
[self presentModalViewController:control animated:YES];
// release at the end
[control release];
[addScreen release];
}
Screenshots: http://cl.ly/032v2k0t0N1s1m3H0511 (you can see the navigation bar as the modal window slides in) http://cl.ly/1h0o453Y3Z051P3S1S37 (the navigation bar of the modal window is covered by the original)
Video: http://cl.ly/1e2J3o1q3V1l1j470m12
It sounds like you failed to consider some of the restrictions and assumptions around using Apple's view controller classes and are getting undefined and unexpected behavior as a result.
Tab bar controllers expect to always be at the root of your controller hierarchy. From the class reference:
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
Additionally modal view controllers (and all view controllers for that matter) are assumed to fill their window.
Related
I have built an app based on a tab bar controller. While I am on one of the tab views I want to be able to swipe my finger and switch to another tab view of which the index on the tabBarController in unknown. I am therefore calling the desired viewcontroller from its nib. The view gets swapped correctly but the problem is that it appears ABOVE the tab bar itself, covering it completely and making it become unusable! How can I push the view back or the tab bar up? Thanks
- (IBAction)swipeLeftDetected:(UIGestureRecognizer *)sender
{
DesiredViewController *controllerInstance =[[DesiredViewController alloc]initWithNibName:#"DesiredViewController" bundle:nil];
controllerInstance.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:controllerInstance animated:YES];
}
presentModalViewController:animated always uses whole screen: On iPhone and iPod touch devices, the view of modalViewController is always presented full screen. On iPad, the presentation depends on the value in the modalPresentationStyle property.
If you really use UITabBarController, it instantiates view controllers of its tabs. So trying to instantiate view controller of one of tabs manually is wrong. You will end in a mess of view controllers instances.
Set property selectedIndex of your UITabBarController to switch tab. I think you need this. But it will be switched without animation.
If you know only pointer of controller you want to switch to, ask viewControllers property about controller's index and than switch tab by its index:
self.selectedIndex = [[self viewControllers] indexOfObject:viewController];
after reading a lot of tutorials and threads here on stackoverflow there is one basic question left in my head.
The structure of my App should be the following:
MainMenu - fullscreen without a navigation bar but 2 buttons (button1 and button2)
Page1 - should appear by pressing button1 and should have a navigation bar at the top with a "back"-button to get back to the MainMenu.
Page2 - should appear by pressing button2 without a navigation bar at the top. Page2 should be a UISplitView. There must be a back button somewhere.
(I think this is where the problem starts, a UISplitView can't be presented modally, can it?)
You should be able to add subpages to Page1.
So how can I do that? I don't need executable code but just a hint on how the structure of my app should be. For example where to add the navigation controller, how the MainMenu looks like.
Thanks in advance!
Are you trying to create an Application for iPad?
Your Application's UI sems inconsistent being First View the only view without navigation Bar.
You will be using standard navigation to navigate to page1 from home page. So you will be adding a navigation Controller with Home View Controller as a Root View COntroller with hidden navigation bar.
eg.
-(void)applicationDidFinishLaunching:...
{
HomeViewController * hvc = [[HomeViewController alloc]init];
UInavigationController * nvc = [[UINavigationController alloc]initWithRootViewController:hvc];
nvc.navigationBar.hidden = YES;
[window addSubView:nvc.view];
}
Then on tap of first Button you will be pushing the Page1 View Controller
-(IBActtion)button1Pressed:(id)sender
{
Page1ViewCOntroller * p1vc = [[Page1ViewCOntroller alloc]init];
[self.navigationController pushViewCOntroller:p1vc animated:YES];
}
In viewWillAppear: method of Page1ViewController unhide the NavigationBar and hide it in the viewWillDisappear: method
Your Page 2 needs to be splitViewController.
Now about Split View, Apple says
The split view controller’s view should always be installed as the root view of your application window. You should never present a split view inside of a navigation or tab bar interface.
But as there is no "must" written in the above statement, and since its finally a View Controller in itselt, you should be able to add it on the window or another view.
Try to create a VIewController, with split VIew added on it, and like page1, push the View on the navigation Controller.
Here is my problem:
I've read a lot about how to use a tab bar within a navigation based application, but i still can't figure it out. I have tried both to use and avoid using a tab bar controller, but i just can't find the solution.
I already have a navigation based app working. I have several nib files (views), each one with its own view controller, that i programmatically push onto the navigation controller stack. I need one of this views to have a tab bar that allows me to switch between some of the others. I understand how the tab bar works, and i do think what i need is to use a tab bar controller, since it would allow me to define the view controllers associated with each tab bar item, and manage all about them. However, i can't see how to do it.
If i do declare a tab bar controller in my "tabBarViewController", draw the tab bar controller in my "tabBarView" and link them with the IB, it will give me an error (I reckon this is because i haven't really pushed the tab bar controller's view? do i need something equivalent to "[window addSubView:[tabbarcontroller view]]?). In this case, all i need to know is how to "see" the tab bar controller's top view controller's view within a view controller i have already pushed.
If i try not to use a tab bar controller, as i have read is the best solution to this problem, ¿how do i manage tab bar items, the switchs between them, etc?
I would really appreciate your help.
You can't push a tab bar controller onto a navigation controller stack. There's just no supported way to do it.
What you may want to consider instead is creating your own instance of UITabBar, then using a delegate that conforms to UITabBarDelegate. That way, your delegate will receive the tabBar:didSelectItem: message whenever a tab bar item is selected by the user. You'll have to manage the NSArray of items for the bar yourself, though, without using IB.
Once you've got that figured out, all that's left to do is push a regular UIViewController onto your navigation stack like any other, and just have that controller manage your tab bar and delegate.
I just made an App with a tabBar controller and 5 navControllers. All you need to do is load the nibs and navigation controller inside the first element of the tabBar controller. You can HIDE the tabBar even if the views are inside it, and make it appear in the view you need it to.
You can do this with a bit of code, like so:
FooViewController *foo = [[FooViewController alloc] init];
BarViewController *bar = [[BarViewController alloc] init];
UITabBarController *tabby = [[UITabBarController alloc] init];
[tabby setViewControllers:[NSArray arrayWithObjects:foo, bar, nil] animated:NO];
[self.navigationController pushViewController:tabby animated:YES];
[foo release];
[bar release];
[tabby release];
You could probably do it with IB as well, just load the tab bar controller from a nib.
I built a sample project that demonstrates this in action, you can download it from http://s3.thismoment.com/navtab.zip
I've come across this twice now.
Sometimes using the following line of code:
[self.navigationController presentModalViewController:aViewController animated:YES];
displays the view, but the navigation bar is then hidden.
I can write:
[self.navigationController setNavigationBarHidden:NO];
to my hearts content, everywhere I can think of with no effect.
Has anyone ran into this?
Am I doing something silly?
No, I ran into this as well. The problem is that when you present a modal view controller with a UIViewController based class, it does not extend the calling navigation controller's nav bar onto the modal. The modal view covers the entire screen. What I ended up doing to solve the problem was to create a UINavigationController and push the UIViewController based class onto it, and then do presentModalViewController to the navigation controller's instance.
like:
UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *cntrol = [[UINavigationController alloc] initWithRootViewController:vc];
[self presentModalViewController:cntrol animated:YES];
[cntrol release];
That allowed me to have a nav bar at the top.
I am not sure if that will help in your particular case, the only other thing I would suggest is to replicate the behavior of the modal with a UIAnimation that stops 44px below the top of the phone. That would keep the original navigation bar visible.
#HeatMiser shows a great way to get around the "bug" surrounding the inability to display items on the nav bar. I'm not sure, however, if this is strictly a bug in Presentation, since modal operations ought to trump the underlying view's interface theme. Having the modal operation's theme mimic the underlying UI theme is fine, but wrapping the true modal view with a navigation view feels wrong to me (extra view object just to get a little more behavior).
Instead, the following worked for me and gives the same behavior as "New Message" does in the Mail program (on the iPhone).
In IB, place a UIToolBar at the top of the modal screen (mimicking the navigation bar) with "Cancel" and "Save" UIBarButtonItem's and a Flexible Space Bar Button Item in between to get the buttons to align left and right. Then, add a UILabel centered over the UIToolBar (The Font Helvetica, Bold, Size 18 appears to match the Navigation Bar Title). Connect the buttons to IBAction's on the modal's UIViewController, and you're done.
If there is a navigation controller active, then you should just use
[self.navigationController pushViewControllerAnimated:how];
to slide another view controller in, while giving yourself and the user into a consistent user interface complete with 'automatic' back button support.
Once a navigation controller is in use, presenting a modal view controller should only be done to enlarge the usable area on the screen. And then, you should really use a fancy animation to let the user know that you are stepping away from the "task" or "steps" that the navigation controller was embodying.
Maybe this is obvious, but once you're done with the modal view and want to dismiss it, you should do something like this in your modal vc:
[parentController dismissModalViewControllerAnimated:YES];
Where parentController is a reference to the vc from where you are presenting the modal view.
I'm trying to implement a UI structured like in the Tweetie app, which behaves as so: the top-level view controller seems to be a navigation controller, whose root view is an "Accounts" table view. If you click on any account, it goes to the second level, which has a tab bar across the bottom. Each tab item shows a different list and lets you drill down further (the subsequent levels don't show the tab bar).
So, this seems like the implementation hierarchy is:
UINavigationController
Accounts: UITableViewController
UITabBarController
Tweets: UITableViewController
Detail view of a tweet/user/etc
Replies: UITableViewController
...
This seems to work[^1], but appears to be unsupported according to the SDK documentation for -pushViewController:animated: (emphasis added):
viewController: The view controller that is pushed onto the stack. It cannot be an instance of tab bar controller.
I would like to avoid private APIs and the like, but I'm not sure why this usage is explicitly prohibited even when it seems to work fine. Anyone know the reason?
I've thought about putting the tab bar controller as the main controller, with each of the tabs containing separate navigation controllers. The problem with this is that each nav controller needs to share a single root view controller (namely the "Accounts" table in Tweetie) -- this doesn't seem to work: pushing the table controller to a second nav controller seems to remove it from the first. Not to mention all the book-keeping when selecting a different account would probably be a pain.
How should I implement this the Right Way?
[^1]: The tab bar controller needs to be subclassed so that the tab bar controller's navigation item at that level stays in sync with the selected tab's navigation item, and the individual tab's table controller's need to push their respective detail views to self.tabBarController.navigationController instead of self.navigationController.
The two previous answers got it right - I don't use UITabBarController in Tweetie. It's pretty easy to write a custom XXTabBarController (plain subclass of UIViewController) that is happy to get pushed onto a nav controller stack, but still lives by the "view controller" philosophy. Each "tab" on the account-specific view (Tweets/Replies/Messages) is its own view controller, and as far as they are concerned they're getting swapped around on screen by a plain-ol UITabBarController.
I'm building an app that uses a similar navigation framework to Tweetie. I've written a post about how to do this on my blog www.wiredbob.com which also links to the source code. It's a full template you could take and use as a basis for another project. Good luck!
It's possible to add a UITabBar to any UIViewController. That way you don't actually have to push a UITabBarController and therefore stay within the guidelines of the Apple API.
In interface builder UITabBar is under "Windows, Views & Bars" in the Cocoa Touch Library.
I do this in a couple of my apps. The trick to adding a tab bar to a navigationController based app is to NOT use a TabBarController. Add a Tab Bar to the view, make the view controller for that view a TabBarDelegate, and respond to user selections on the tab bar in the code of the view controller.
I use Tab Bars to add additional views to the Tab Bar's view as sub-views, to reload a table view with different datasets, to reload a UIPickerView, etc.
I was struggling for the past hour to implement a UITabBar because it would get hidden when I tried to display my view; then I found this post:
Basically, make sure you insert your new view below the tabbar, per this line of code:
[self.view insertSubview:tab2ViewController.view belowSubview:myTabBar];
In my app, the root view controller is a UINavigation controller. At a certain point in the app, I need to display a UITabBar. I tried implementing a UITabBar on a UIView within the navigation hierarchy, as some of the previous posts suggested, and this does work. But I found that I wanted more of the default behavior that the tab controller provides and I found a way to use the UITabBarController with the UINavigation controller:
1) When I want to display the UITabBarController's view, I do this:
MyAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
appDelegate.window.rootViewController = myUiTabBarControllerInstance;
2) When I want to return to where I was in the navigation hierarchy, I do this:
appDelegate.window.rootViewController = myNavControllerInstance;
This could be achieved by simply embedding the TabBarController in the Navigation Controller.
In the storyboard:
Drag a ViewController
Click on the ViewController's Scene
Click on editor >> Embed in >> Navigation Controller.
Drag a button on the same ViewController.
Drag a TabBarController
Connect the button on the ViewController to the TabBarController via push Segue Action.
In this case only the TabBarController's RootViewController would be in the Navigation Controller's stack. All The TabBarItems would have the Navigation Bar at the top and user can go to Home Screen at any time, irrespective of the selected TabBarItem
This could be done at any ViewController in the Navigation Controller's stack.
If it works, please suggest me how to increase the reputation so that I can post the images and the code in the next answer. :)
This is how i did it. This is actually pushing a tabbarcontroller onto navigation controller. It works fine. I didn't find anywhere in the documentation that apple doesn't support this way. Can someone give me link to this warning?
If this is truth, is it possible that apple refuses to publish my app to appstore?
-(void)setArrayAndPushNextController
{
MyFirstViewController *myFirstViewController = [[MyFirstViewController alloc] init];
MySecondViewController *mySecondViewController = [[MySecondViewController alloc] init];
myFirstViewController.array = self.array;
NSArray *array = [[NSArray alloc] initWithObjects:myFirstViewController, mySecondViewController, nil];
UITabBarController *tab = [[UITabBarController alloc] init];
tab.viewControllers = array;
[array release];
UITabBarItem *item1 = [[UITabBarItem alloc] initWithTitle:#"first title" image:nil tag:1];
UITabBarItem *item2 = [[UITabBarItem alloc] initWithTitle:#"second title" image:nil tag:2];
myFirstViewController.tabBarItem = item1;
mySecondViewController.tabBarItem = item2;
[self stopAnimatingSpinner];
[self.navigationController pushViewController:tab animated:YES];
[tab release];
[item1 release];
[item2 release];
}
I wrote a blog post on how I approached this problem. For me, using a modal view was a simpler solution than writing a custom tab-bar implementation.
http://www.alexmedearis.com/uitabbarcontroller-inside-a-uinavigationcontroller/