I am trying to display a UISplitViewController presenting it as a Modal View Controller in my iPad app. I manage to have it display, but for some reason there is a gap to the left of the modal view the size of a Status Bar which is also preserved when the orientation is changed.
Does anybody know why this is happening? Or if this is even possible? Maybe I'm just digging myself a huge hole.
Like for many of you, I needed a 'modal way' to use the UISplitViewController. This seems to be an old issue, but all I found in StackOverflow was at best an explanation why the problem happens when you attempt to do so (like the accepted answer above), or 'hack-arounds'.
However, sometimes it is also not very convenient to change much of your code-base and make a UISplitViewController the initial object just to get it's functionality up and running.
In turns out, there's a way to make everybody happy (including Apple guidelines). The solution that I found best, was to use the UISplitViewController normally, but when needed to be shown/dismissed, use the following approach:
-(void)presentWithMasterViewController: (UIViewController *) thisMasterViewController
andDetailViewController: (UIViewController *) thisDetailViewController
completion:(void(^)(void))completion
{
masterViewController = thisMasterViewController;
detailViewController = thisDetailViewController;
[self setViewControllers:[NSArray arrayWithObjects:masterViewController, detailViewController, nil]];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.autoresizingMask = UIViewAutoresizingFlexibleWidth|UIViewAutoresizingFlexibleHeight;
self.window.rootViewController = self;
[self.window makeKeyAndVisible];
if(completion)
completion();
}
-(void)dismissViewControllerWithCompletion:(void (^)(void))completion
{
self.window = nil;
masterViewController = nil;
detailViewController = nil;
if(completion)
completion();
}
Where "window", is a property of your UISplitViewController subclass. And the system will take care of the rest!
For convenience/reference, I uploaded this as a UISplitViewController subclass to gitHub:
ModalSplitViewController
--EXAMPLE ON HOW TO USE --
mySplitViewController = [[ModalSplitViewController alloc] init];
mySplitViewController.delegate = self;
[mySplitViewController presentWithMasterViewController:masterViewController andDetailViewController:detailViewController completion:nil];
// when done:
[mySplitViewController dismissViewControllerWithCompletion:nil];
mySplitViewController = nil;
Side-note: I guess most of the confusion originates from the fact that
the UISplitView usage example from Apple documentation uses the window
created in the appDelegate, and for the fact that most people are not
so familiar with the window concept - because we normally don't need
to (they are created once in StoryBoards or boilerplate code).
Additionally, if you are doing state restoration, one should not
forget that programmatically-created UIViewControllers won't
automatically be restored by the system.
The stock UISplitViewController was designed for use as the root view controller only. Presenting one modally goes against the Apple Human Interface Guidelines and has a high probability of getting rejected by the App Review Team. In addition, you may receive the error:
Application tried to present Split View Controllers modally
Technically, this is what I did:
1/ Subclass a UIViewController ie. #interface aVC: UIViewController
2/ In the viewDidLoad, set up a splitViewController, ie. aSplitVC
3/ Then self.view = aSplitVC.view
After all, present aVC as modalViewController
I agree with Evan that this is slightly off-color for Apple, but I was able to complete a working version of this with the following solution:
UISplitViewController *splitVC = [[UISplitViewController alloc] init];
splitVC.delegate = VC2;
splitVC.viewControllers = [NSArray arrayWithObjects:navcon1, navcon2, nil];
UINavigationController *splitNavCon = [[UINavigationController alloc] init];
splitNavCon.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[splitNavCon.view addSubview:splitVC.view];
VC2.splitParentViewController = splitNavCon;
[self presentViewController:splitNavCon animated:YES completion:nil];
This allowed me to have a working back button in the new UISplitViewController that was presented modally on the screen.
You'll notice that I actually pass the VC2 (the delegate of the UISplitViewController) its parent UINavigationController. This was the best way that I found I could dismiss the UISplitViewController from within the VC2:
[splitParentViewController dismissViewControllerAnimated:YES completion:nil];
I believe one can do the other way around: instead of custom controller presenting split controller, one can set up the split controller as the root window controller in storyboard, and on top of its view you can add your custom controller (ie, login screen) and remove it from the screen (removeFromSuperview for example) when it is needed.
That answer is not actually correct, because it not valid any longer since iOS8 and if you need to support even iOS7 you can do that like you put actually modally UIViewController which has a container as SplitView.
let mdSplitView = self.storyboard?.instantiateViewControllerWithIdentifier("myDataSplitView") as! MyData_SplitVC
self.addChildViewController(mdSplitView)
mdSplitView.view.bounds = self.view.bounds
self.view.addSubview(mdSplitView.view)
mdSplitView.didMoveToParentViewController(self)
Related
So I'm trying to convert a single view application into a tabbed application. My use case is this - in one of the view controllers I want to push a new view controller and still have the tab underneath.
I'm currently doing this -
[self.tabBarController setViewControllers:#[self.searchViewController, self.loginViewController]];
[self.searchViewController presentViewController:self.searchViewController.detailController animated:YES completion:nil];
However, this makes the tab across the bottom disappear.
What should I do?
presentViewController is a "modal" presentation - the presented view controller takes over the entire screen. If you want to remain within the tab but move between view controllers, the root view controller in the tab should be a UINavigationController. You can then push/pop view controllers onto that.
There are two primary methods for view navigation, the first is a presentation which displays a view from the bottom that slides up, and the second is a push which displays a view from the right that slides in from the side.
In most cases, the view I am going to display and what action kicked off the navigation determine which method I will use. For example, if I have a table view that has a list of music albums and I want to search for a song by a particular artist, to see the songs within that album I want to PUSH the view controller, i.e. slide to the right. This gives me the built-in (and intuitive) ability to go back via the automatically added back button on the navigation bar in case the song I was looking for wasn't in the album I selected.
If perhaps I wanted to present the user with the ability to edit the album details, such as renaming the album, this is a totally different type of action, and I would want to PRESENT such a view modally, i.e. from the bottom.
The major distinction between the two is where are you going and what are you doing. If the next view you are going to show is something that does one action and you are then returned back to the original view, presenting modally from the bottom is conventional. If you are doing to be potentially navigation further and further into subsections and will be coming back and forth between said subsections, like Artist->Album->Song etc., you are going to want to push the view from the side, just like the default music app in iOS does.
This is an example starter project I created that demonstrates an easy way to make this work the way you likely want. I create instances of the different view controllers I want to be contained in the tabBarController, which are associated with the tabs, and then "wrap" them each with their own navigation controller before adding them to the tabBar via the .items property. This way each view controller has its own navigation hierarchy and within each you'll be able to call [self.navigationController pushViewController:] or [self.navigationController presentViewController] to keep the navigation 'within' the views and separate from the tabBar itself.
#import "AppDelegate.h"
#import "TabBarViewController.h"
#import "InfoViewController.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.backgroundColor = [UIColor whiteColor];
InfoViewController *firstVC = [[InfoViewController alloc] init];
firstVC.title = #"First";
firstVC.view.backgroundColor = [UIColor redColor];
UINavigationController *firstNC = [[UINavigationController alloc] initWithRootViewController:firstVC];
InfoViewController *secondVC = [[InfoViewController alloc] init];
secondVC.title = #"Second";
secondVC.view.backgroundColor = [UIColor blueColor];
UINavigationController *secondNC = [[UINavigationController alloc] initWithRootViewController:secondVC];
TabBarViewController *tabBarVC = [[TabBarViewController alloc] init];
tabBarVC.viewControllers = #[firstNC, secondNC];
self.window.rootViewController = tabBarVC;
[self.window makeKeyAndVisible];
return YES;
}
That resulted in the following:
Hope that helps!
I created and loaded a UISplitViewController in an existing ViewController by writing the following code in the viewDidLoad method:
LeftPanelViewController *leftPanel = [[LeftPanelViewController alloc] initWithNibName:#"LeftPanelViewController" bundle:nil];
FirstViewController *firstView = [[FirstViewController alloc] initWithNibName:#"FirstViewController_iPad" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:firstView];
UISplitViewController *splitController = [[UISplitViewController alloc] init];
splitController.viewControllers = [NSArray arrayWithObjects:leftPanel, self.navigationController, nil];
[self.view addSubview:splitController.view];
[self addChildViewController:splitController];
[splitController didMoveToParentViewController:self];
Everything is fine except for the fact that the splitController is not being drawn in the borders of the iPad, there's a space between the top of the screen and the top of the view. Even when I rotate the iPad the left panel is also having the same problem.
SplitViewController doesn't have a xib file, and when I change the added view for another that has, everything is correctly displayed.
Any ideas of what may cause this problem?
Notes:
Compiling and running the project in the simulator multiple times causes the SplitViewController to be displayed sometimes without any problems and others with spaces between any of the edges of the screen and the view. Running in the iPad causes always the same problem.
First of all.. why do you implement a container view controller? I guess you just want to present the splitViewController on its own, right? Than don't add the view yourself.
Instead correctly set it as your rootViewController on your window (preferably in applicationDidFinishLaunching).
self.window.rootViewController = splitViewController;
Container View Controller are not needed in standard cases. So you should never need to use the following methods:
addChildViewController:
removeFromParentViewController
willMoveToParentViewController:
didMoveToParentViewController:
Check the documentation of UIViewController.
If you really wanted to implement a Container View Controller, than you need to take care of the layout yourself. So you need to position / size the view of the other controller yourself. Depending on if you use AutoLayout or autoresizing, you need to set correct constraints/flags.
What i'm doing is this:
UIViewController *rootController = [[[UIApplication sharedApplication] keyWindow] rootViewController];
AlarmRingViewController *alarmController = [[AlarmRingViewController alloc] init];
[rootController presentViewController:alarmController animated:YES];
What i want to achive with this, is to push my AlarmRingViewController on top of any other controller which is displaying at the moment and it works so far.
Now im wondering if this is good practice:
to instatiate a new viewController each time it should be presented
do so in a non UI related class? (in my case a scheduler for NSTimer)
from there push the newly created viewController with the rootViewController on top
Or does this violate the MVC pattern or Apples guidelines or anything.
cheers
Personally I think it's ugly code. It's hard to read and hard to debug. Split the code up a bit:
UIViewController *rootController = [[[UIApplication sharedApplication] keyWindow] rootViewController];
AlarmRingViewController *alarmController = [[AlarmRingViewController alloc] init];
[rootController presentViewController:alarmController animated:YES];
There is no benefit to typing so much into one line.
Update: Based on your updated question:
There is no problem instantiating a new view controller each time you need it. This is very common. It might be appropriate to create one and cache it. This is an optimization that could make sense if only one of the view controllers is every shown at any given time, the view controller is used very often, and it takes a lot of time to create.
View controllers are usually created and presented by other (view) controllers.
Why don't you just use a UINavigationController as the root view controller. That way, you can just do this:
AlarmRingViewController *alarmController = [[AlarmRingViewController alloc] init];
[self.navigationController presentViewController:alarmController animated:YES completion:nil];
I read that it is bad to have such structure in an iOS application. But what if an application has a lot of UINavigationControllers and UITabBarControllers. But one UINavigationBar and one UITabBar are always displayed only? Other UINavigationBars and UITabBars are hidden.
EDITED
For example, in navigation-based application I call this code:
- (IBAction)openTabsController:(id)sender {
tabOneController *tabOneViewContr = [[[tabOneController alloc] initWithNibName:#"tabOneController" bundle:nil] autorelease];
UINavigationController *tabOneNavContr = [[UINavigationController alloc] initWithRootViewController:tabOneViewContr];
tabTwoController *tabTwoViewContr = [[[tabTwoController alloc] initWithNibName:#"tabTwoController" bundle:nil] autorelease];
UINavigationController *tabTwoNavContr = [[UINavigationController alloc] initWithRootViewController:tabTwoViewContr];
UITabBarController *tabContr = [[[UITabBarController alloc] init] autorelease];
tabContr.viewControllers = [NSArray arrayWithObjects:tabOneNavContr,tabTwoNavContr, nil];
sel.navigationController.navigationBar.hidden = YES;
[self.navigationController pushViewController:tabContr animated:YES];
}
After calling of this method I have two UINavigationControllers and one UITabBarController. At the same time I have one UINavigationBar and one UITabBar on a screen.
EDITED
Approximate scheme.
From The beginning we have an UINavigationController which allows to navigate between the views (circles). Then after pushing an UITabBar appears and allows to switch between the views. A rectangle with two little rects is a view with a UITabBar with 2 UITabBarItem s. When we presss any UITabBarItem another UIView appears. In this UIView we can press some button which calls another view with another UITabBar. Current UITabBar is visible after pushing if it is not hidden with another UITabBar.
is it more clear now?
The code above works almost perfect (except of some animations and not including Apple's limitations)
Gargo,
I'm not sure I understood your question but the apple documentation is clear. If you use - (void)pushViewController:(UIViewController *)viewController animated:(BOOL)animated it says that viewController:
cannot be an instance of tab bar controller and it must not already be
on the navigation stack.
Since you do
[self.navigationController pushViewController:tabContr animated:YES];
you are pushing a tab bar controller instance within the navigation stack.
If you add the structure that you would achieve maybe I can help you to find another solution.
Hope that helps.
An app should only have one working tabBarController at any one time.
A tabBarController should also be the root view controller. Always. (If you need a login view or similar before the tabBarController, then remove the login view, create the tabBarController and then make that the root).
This is Apple' advice spoken to me personally by Apple engineers.
Remember, apps should be small applications that are quick and easy to use/navigate. If you feel the need for more than one tabBarController then your app design is likely very wrong from a UI/Usability perspective.
Preface: I am not using *.xib files.
I instantiate a UINavigationController in a class that effectively serves as my 'rootViewController'. This 'rootViewController' also has two UITableViewController members that are drawn on different sections of the iPad screen. One of which is set as the root view for the navigation controller. Let's call it tableViewControllerA.
The problem is, when I invoke pushViewController on a valid UINavigationController, I see no effect:
[tableViewControllerA.navigationController pushViewController:tableViewControllerX animated:YES];
I've gathered from the posts I've searched today, that this push method should in turn cause the screen to redraw the top of stack controller.view. This is not what I'm seeing.
It seemed there was a disconnect in my implementation, and it was time to reference a working example in my environment (xcode 4.0). Assuming the canned templates would provide a working basis, I created a new navigation-based applications. I simply modified didFinishLaunchingWithOptions: as follows.
UIViewController *view1 = [[UIViewController alloc] init];
UIViewController *view2 = [[UIViewController alloc] init];
view1.title = #"view1";
view2.title = #"view2";
[self.navigationController pushViewController:view1 animated:YES];
[self.navigationController pushViewController:view2 animated:YES];
self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:view1];
[view1 release];
[view2 release];
I found similar results. When I launch the simulator the screen title reads the title of whatever the self.window.rootViewController is pointing at. With the code as is, the title of the resulting top screen reads "view1". When I initWithRootViewController:view2, the resulting top screen reads "view2".
So please tell me I'm stupid cuz xyz...
Thanks.
Here are some references and suggestions:
Simple tutorial for navigation based application:
http://humblecoder.blogspot.com/2009/04/iphone-tutorial-navigation-controller.html
Here is another one to create the step by step navigation controller and adding the views:
http://www.icodeblog.com/2008/08/03/iphone-programming-tutorial-transitioning-between-views/
and here a bit advance with navigation + tab bar controller:
http://developer.apple.com/library/ios/#featuredarticles/ViewControllerPGforiPhoneOS/CombiningToolbarandNavigationControllers/CombiningToolbarandNavigationControllers.html
Without seeing your code, I have 2 theories:
Your syntax and calls are wrong when you do the push. Use this as a model:
-(void)Examplemethod {
AnotherClassViewController *viewController = [[[AnotherClassViewController alloc] initWithNibName:#"AnotherClassView" bundle:nil] autorelease];
[self.navigationController pushViewController:viewController animated:YES];
}
You are never adding the navigation controller to the view hierarchy which never adds the view either. Take a look at this.