In my code I am using the present(:animated:completion:) method to present ViewController2 from ViewController1 that is the root view controller of a container view nested within RootViewController.
I've set the presentation style to be .coverVertical and I have ViewController1's definesPresentationContext variable set to true in it's viewDidLoad() method. I also have ViewController2's presentation set to .overCurrentContext. This makes ViewController2's bounds the same as ViewController1's but for whatever reason the .coverVertical animation starts at the bottom of the screen instead of starting from the bottom of ViewController1's frame.
However, this goes away when I set the root view controller of the container view to be a UINavigationController and nest ViewController1 within it. I assume this means that there is some second context variable that I'm missing that prevents the animations from animating overtop other views, but I couldn't seem to find any other variables besides definesPresentationContext.
So you are saying that your view controller hierarchy is
RootViewController
ViewController1
In that case, run this code inside ViewController1:
let vc = // ViewController2 instance, obtained somehow
vc.modalTransitionStyle = .coverVertical
self.definesPresentationContext = true
vc.modalPresentationStyle = .currentContext
self.present(vc, animated: true)
You will see that only the area of ViewController1's view is involved in the transition.
Note that the clipsToBounds of the container view must be set to true. If there is no container view, add one (to provide the clipping) — though I believe, from your description, that there is one (i.e. that you configured this in a storyboard).
Related
What's the difference between adding a viewcontroller's view inside another view controller's view and embedding a view controller like this:
addChildViewController(controller)
self.view.addSubview(controller.view)
controller.view.frame = view.bounds
controller.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
controller.didMove(toParentViewController: self)
Embedding a view controller (View Controller Containment) has added benefits such as calls being made to viewDidAppear, viewDidDisappear and rotation and resizing events being passed to the view controller to handle. These don't happen when you just add a view directly.
Having some trouble permanently moving one from view controller to another. The normal segues seem to all have a 'go back' option.
I know I can imbed the VC in a navigation controller and create a custom segue which rewrites the hierarchy/changes root VC
class ReplaceSegue: UIStoryboardSegue {
override func perform() {
source.navigationController?.setViewControllers([self.destination], animated: false)
}
}
But I want to avoid a navigation controller as it will confuse things when I add a SWRevealViewController later.
Can/Should I change the storyboard VC (outside of AppDelegate that is)?
Thanks - apologies if this is a 'beginner' question
You can either change rootViewController of your main window:
self.window.rootViewController = vc
or you can just simply set vc's modalPresentationStyle to fullscreen (this doesn't have a "go back" option by itself, only you can dismiss it calling dismiss)
let vc = UIViewController()
vc.modalPresentationStyle = .fullScreen
or from storyboard change it's presentation style to fullscreen.
It's easier to show you a drawing and then explain.
Dashboard Storyboard
I have 2 separate UIViewControllers (i've included just one in the drawing, the other is irrelevant) embedded in container view called ContainerViewController.
Post Storyboard
NewPostViewController shows a UIButton that presents TextPostViewController. As you can see, all of them are embedded in UINavigationControllers. Now, once the completion block of the new post is being called, I have to present the ContainerViewController and it needs to handle it's own logic. The problem is that it's embedded in UINavigationController and once I present it, the UITaBbar is hidden.
I tried to do this:
self.performSegue(withIdentifier: "TextPostToNavContainerVC", sender: nil)
The transition is successful but I'm losing the UITabBar, even though in the DashboardViewController and the ContainerViewController I called:
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
tabBarController?.tabBar.isHidden = false
}
What am I doing wrong or is there are better way to do that?
You should instantiate the tab bar controller. not the view controller.
Imagine you're putting a initial view controller ahead of your tab bar controller. Making your tab bar not being pushed
If I undestand it correctly.
You are doing this
Segue connect to a view controller
But you should actually do this Segue connected to a tab bar controller
You can try to add it as a child to control it's frame like this
let textPost = self.storyboard?.instantiateViewController(withIdentifier: "containerID") as! TextPostToNavContainerVC
textPost.view.frame = CGRect(x:20,y:0,width:self.view.frame.width,height:self.view.frame.height-50)
self.view.addSubview(nvc.view)
self.addChildViewController(textPost)
textPost.didMove(toParentViewController: self)
I am making an app at the moment where 1 screen has a segmented control with 3 segments. Initially I had 1 table view and when you change segment I would simply change the data source/cell etc and reload the table. While this works great there is always the problem that when you change segments it will not remember your last scroll position because the table view gets reloaded.
I tried to get around this with storing offset position, rows etc but I could never get it to work like I wanted. Seems especially annoying when you have different cell types for the segments and they are self sizing as well.
I than decided to have a master view controller with the segmented control and 3 container views with their own VC and table view for each segment. I simply hide/show the correct container view when changing segments. This also works great but I have 1 problem with iOS 11 style large headers. Only the 1st container view added as a subview to the ViewControllers view manipulates the collasping/expanding of the title when you scroll.
Therefore when I change to the 2nd or 3rd container view and start scrolling I do not get the large title collapsing animation. How can I get around that?
I tried the following
1) Change Container view zPosition when changing segments
2) Move the container view to the front by calling view.bringSubview(toFront: ...)
3) Looping through the subviews and calling
view.exchangeSubview(at: 0, withSubviewAt: ...)
I believe I could remove all container views and add the one I need again and give them constraints but I wonder if there is a more straight forward solution.
Or if someone has a good solution to remember a tableViews scroll position before reloading it I would appreciate that too.
So I found an answer that seems to work for me, thanks to this great article. https://cocoacasts.com/managing-view-controllers-with-container-view-controllers/
Essentially what I did is
1) Remove the ContainerViews and Segues from the MasterViewController Storyboard.
2) Add a lazy property for each VC of the segmented control in the MasterViewController. They are lazy so that they only get initialised when you actually need them
lazy var viewController1: LibraryViewController = {
let viewController = UIStoryboard.libraryViewController // convenience property to create the VC from Storyboard
// do other set up if required.
return viewController
}()
lazy var viewController2: LibraryViewController = {
let viewController = UIStoryboard.libraryViewController // convenience property to create the VC from Storyboard
// do other set up if required.
return viewController
}()
3) Create an extension of UIViewController with the following 2 methods. I added them in an extension purely for code organisation as they might be reused on other ViewControllers.
extension UIViewController {
func add(asChildViewController viewController: UIViewController) {
// Add Child View Controller
addChildViewController(viewController)
// Add Child View as Subview
view.addSubview(viewController.view)
// Configure Child View
viewController.view.frame = view.bounds
viewController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
// Notify Child View Controller
viewController.didMove(toParentViewController: self)
}
func remove(asChildViewController viewController: UIViewController) {
// Notify Child View Controller
viewController.willMove(toParentViewController: nil)
// Remove Child View From Superview
viewController.view.removeFromSuperview()
// Notify Child View Controller
viewController.removeFromParentViewController()
}
}
4) Now in my segmented control method that gets called when you change segment I simply add the correct ViewController. The nice thing is that remove/adding them does not actually deallocate them.
func didPressSegmentedControl() {
if segmentedControl.selectedSegmentIndex == 0 {
remove(asChildViewController: viewController2)
add(asChildViewController: viewController1)
} else {
remove(asChildViewController: viewController1)
add(asChildViewController: viewController2)
}
}
5) Make sure you call the method at point 4 in ViewDidLoad so that the correct VC is added when the VC is loaded the 1st time.
func viewDidLoad() {
super.viewDidLoad()
didPressSegmentedControl()
}
This way when we remove a ChildViewController and add another one it will always be the the top VC in the subviews array and I get my nice title collapsing animation.
Another added benefit of this approach is that if you never go to a particular segment that particular VC will never get initialised, because they are lazy properties, which should help with efficiency.
Hope this helps somebody trying to do the same.
This is a horrible issue which I hope will be resolved soon, but there is another fix - although I freely admit that this is a nasty hack.
Basically, the issue only applies to the FIRST container view in the hierarchy. Add another container view to your hierarchy. Set it as hidden, then delete its segue and its target view controller just to be neat. Finally, make sure that this is the first container view in the hierarchy by dragging it to the top of the list.
My custom AVPlayerViewController won't autorotate if the previous view controller has been instantiated. If I present the AVPlayerViewController, it rotates, and if I present the previous view controller, it rotates. Here's my code for instantiating a view controller :
let vc = self.storyboard!.instantiateViewController(withIdentifier: "MovieVC") as! MovieVC
vc.movie = self.movie
self.navigationController?.pushViewController(vc, animated: true)
In this situation I am creating a copy of the current view controller with different information. If there is no way to fix the autorotating error, is there a different way to present the same view controller?
The problem is that you are not presenting the view controller. You are pushing it. That means that the navigation controller itself is in charge of rotation, so you don't get any special autorotation for this view controller.
The only way to give this view controller its own power over autorotation is to present it:
self.present(vc, animated: true)