Content pushed down in a UIPageViewController with

Question

UPDATE 2

I've been running and testing my app in the iOS Simulator using a 4-inch device. If I run using a 3.5-inch device the label doesn't jump. In my .xib, under Simulated Metrics, I have it set as Retina 4-inch Full Screen. Any idea why I'm only seeing this problem on a 4-inch device?

UPDATE 1

In IB, if I choose "Navigation Bar" in Simulated Metrics, my label still jumps. The only way I can get my label to render correctly on the first screen is to not set a navigation controller as my window's root view controller.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

My window's rootViewController is being set to a UINavigationController whose rootViewController has a UIPageViewController embedded.

When my app loads, the initial view is presented with it's content pushed down a bit, roughly the same size as a navigation bar. When I scroll the pageViewController, the content jumps up to where it was placed in the nib, and all other viewControllers loaded by the pageViewController are fine.

In my appDelegate:

self.window.rootViewController = [[UINavigationController alloc] initWithRootViewController:[ContainerViewController new]];

In ContainerViewController:

- (void)viewDidLoad {

    [super viewDidLoad];

    self.pvc = [[UIPageViewController alloc] initWithTransitionStyle:UIPageViewControllerTransitionStyleScroll
                                               navigationOrientation:UIPageViewControllerNavigationOrientationHorizontal
                                                             options:nil];
    self.pvc.dataSource = self;
    self.pvc.delegate = self;
    DetailViewController *detail = [DetailViewController new];
    [self.pvc setViewControllers:@[detail]
                       direction:UIPageViewControllerNavigationDirectionForward
                        animated:false
                      completion:nil];

    [self addChildViewController:self.pvc];
    [self.view addSubview:self.pvc.view];
    [self.pvc didMoveToParentViewController:self];
}

Answer 1

As @djibouti33 already posted:

a pageViewController couldn't properly lay out it's child view controller initially if it contained a scroll view. by the time we're in layoutSubviews, pageViewController seems to have gotten it's bearings and everything is laid out just fine

By waiting for layoutSubViews to load before setting any viewControllers to the UIPageViewController was the only thing that worked for me.

override func viewDidLoad() {
    super.viewDidLoad()
    self.pageViewController = self.storyboard?.instantiateViewController(withIdentifier: "yourPageViewController") as? UIPageViewController       
    self.pageViewController?.dataSource = self

    pageViewController?.automaticallyAdjustsScrollViewInsets = false    
    self.pageViewController?.view.frame = CGRect(x: 0, y: 0, width: view.frame.size.width, height: view.frame.height)       
    self.addChildViewController(self.pageViewController!)        
    self.view.addSubview((self.pageViewController?.view)!)       
    self.pageViewController?.didMove(toParentViewController: self)
}


override func viewDidLayoutSubviews() {
    let startVC = self.viewControllerAtIndex(index: 0) as infoDataViewController     
    let viewControllers = NSArray(object: startVC)    
    self.pageViewController?.setViewControllers(viewControllers as? [UIViewController], direction: .forward, animated: true, completion: nil)
}

Answer 2

this is my first time posting on stack overflow, but I have searching for a solution to this problem for over a week now.

Here is a solution I came up with, I hope this works for anyone else with the same issue.

I'm not sure how you are initializing your frame for your detail view controller, but I am going to assume you might use: self.view.frame.size.height;

try using: self.view.frame.size.height -= self.navigationController.navigationBar.bounds.size.height;

Hope this helps

Answer 3

This is definitely being caused by automaticallyAdjustsScrollViewInsets, as other posters (including @djibouti33). However, this property is strange in two ways:

1. It must be set on a UINavigationController. If you set it on a child controller that's managed by a UINavigationController, it won't have any effect. 1
2. It only applies when a scroll view is at index zero in a controller's subviews. 2

These two caveats should explain the intermittent problems experienced by others in the thread.

TLDR: A workaround that I went with is adding a dummy view to the UIPageViewController at index zero, to avoid the setting applying to the scrollView within the page controller, like this:

pageViewController.view.insertSubview(UIView(), atIndex: 0) // swift

[pageViewController.view insertSubview: [UIView new] atIndex: 0]; // obj-c

Better would be to set the contentInset on the scroll view yourself, but unfortunately the UIPageViewController doesn't expose the scroll view.

Answer 4

So I'm adding another answer after further development and I finally think I figured out what's going on. Seems as though in iOS7, UIPageViewController has its own UIScrollView. Because of this, you have to set automaticallyAdjustsScrollViewInsets to false. Here's my viewDidLoad now:

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.automaticallyAdjustsScrollViewInsets = false;

    DetailViewController *detail = [[DetailViewController alloc] init];
    [self setViewControllers:@[detail]
                   direction:UIPageViewControllerNavigationDirectionForward
                    animated:false
                  completion:nil];
}

No need to put anything in viewWillLayoutSubviews (as one of my previous answers suggested).

Answer 5

As stated by "Bo:": Putting self.edgesForExtendedLayout = UIRectEdgeNone; in the viewDidLoad of MyPageViewController solved the problem. – Bo

Answer 6

Try unchecking these 2 options on your storyboard