I have a function inside my app delegate which is supposed to push a View Controller when called from a Siri Shortcut.
func pushNewView() {
if let wind = UIApplication.shared.delegate?.window {
if let rootViewController = wind?.rootViewController {
let viewToPush = TripTableViewController()
if let alreadySomeOneThere = rootViewController.presentedViewController {
alreadySomeOneThere.navigationController?.pushViewController(viewToPush, animated: true)
} else {
rootViewController.navigationController?.pushViewController(viewToPush, animated: true)
}
}
}
}
When I called pushNewView() from my AppDelegate, nothing happens.
If I present the view controller instead of pushing it, that does work but I want the view controller pushed.
I'm not using any storyboards, all my code is programmatic.
Does anyone know how to make this function successfully push the View Controller?
Nothing is happening because neither alreadySomeOneThere nor rootViewController are embedded in a navigation controller.
In order to push another view controller, there needs to be an existing navigation controller in place.
You need to do one of two things. Either redo your setup such that alreadySomeOneThere and rootViewController are embedded in a navigation controller, or you need to present the new view controller from alreadySomeOneThere or rootViewController.
Please note that you can't push a navigation controller. If you choose to put alreadySomeOneThere and rootViewController in a navigation controller, then just push viewToPush. Don't create another navigation controller.
If you instead decide to present the new view controller from alreadySomeOneThere or rootViewController, then depending on the needs of viewToPush, you may or may not need viewToPush embedded its own navigation controller.
Related
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.
I have : navigation controller -> tableViewController -> tab bar Controller -> ViewController1 / ViewController2 / ViewController3
I click on a cell on the TableViewController and I open the TabBar. All is OK
But, I wanted to have more details from the datas in the TableViewController so I decided to make a popup with the content of the cell. I found this tutorial https://www.youtube.com/watch?v=S5i8n_bqblE => GREAT ! It's about the use of segue "present modally" with a viewcontroller containing the popup. I made a link from the popup to the tabBarController and I lose the Navigation Bar
I tried to play with navigationBar but nothing is working. I changed the type of segue but I don't obtain what I want.
I think the problem come from the type of segue. It's OK if I use it like a go/back in viewController. Do you have any solution about using this sort of popup or do I have to use another way ?
Thanks
Ok, let's take a look.
Navigation Bar is a view which is provided by Navigation Controller. Sometimes we are confused with navigation bars and navigation items. Navigation bar is the only one and it belongs to navigation controller, navigation item belongs to individual view controller from navigation stack. So, first step is simple: if you want navigation bar, wrap your modally presented controller into navigation stack.
Yes, you will face other problem, the blurred view of previous controller will become a black area. Why? there is special object called Presentation Controller (UIPresentationController) which is responsible for how controller will be presented. And it hides view of previous controller by default (in sake of performance, I think).
Ok, let's move. We can create custom presentation controller and tell it not to hide view of previous controller. Like this:
class CustomPresentationController: UIPresentationController {
override var shouldRemovePresentersView: Bool {
return false
}
}
Next step. In controller we want present modally we have to specify to things: we want to use custom presentation controller and we also want to adjust delegate object for transitioning (where we can specify custom presentation controller). The trick is that you have to do it inside initialiser, because viewDidLoad is too late: controller had been already initialised:
class PopupViewController: UIViewController {
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
modalPresentationStyle = .custom
transitioningDelegate = self
}
}
Final step. When PopupViewController became delegate for its own transitioning, it means this controller is responsible for all of them. In our particular case popup controller provides custom version of presentation controller. Like this:
extension PopupViewController: UIViewControllerTransitioningDelegate {
func presentationController(forPresented presented: UIViewController, presenting: UIViewController?, source: UIViewController) -> UIPresentationController? {
return CustomPresentationController(presentedViewController: presented, presenting: presenting)
}
}
That's all. Now you should see view of previous controller.
I have VC1 which is a basic view controller, I then want to present VC2 which is inside a navigation controller. Whenever I present it, it doesn't display the navigation controller. I want this all done pragmatically. The code I have been using to present VC2 is:
func matchesPressed(sender: UIButton!) {
let matchesTVC: Matches = self.storyboard?.instantiateViewControllerWithIdentifier("Matches") as! Matches
self.presentViewController(matchesTVC, animated: true, completion: nil)
}
How do I present the navigation controller it is inside as well?
Is the navigation controller in the storyboard? If so, give it a storyboard ID and replace your matchesTVC stuff with the navigation controller.
If matches is a standalone view controller in the storyboard, you can do it in code like this:
let matchesTVC: Matches = self.storyboard?.instantiateViewControllerWithIdentifier("Matches") as! Matches
let navContr = UINavigationController(rootViewController:matchesTVC)
self.presentViewController(navContr, animated: true, completion: nil)
Instantiate the navigation controller that contains your view controller and present the navigation controller.
Using XCode 6.1 I am trying to roll my own View Controller containment with a custom menu... I am using the following function within my Main View Controller to present child view controllers:
var currentController: UIViewController?
// Function within main view controller class
func presentController(controller: UIViewController) {
if currentController != controller {
if currentController != nil {
currentController!.willMoveToParentViewController(nil)
currentController!.view.removeFromSuperview()
currentController!.removeFromParentViewController()
}
controller.willMoveToParentViewController(self)
self.addChildViewController(controller)
self.view.addSubview(controller.view)
controller.didMoveToParentViewController(self)
currentController = controller
}
}
When the app is initially run I use self.presentController(firstViewController) inside viewDidAppear, which works.
However, in my custom menu (using REMenu) outside of the Main View Controller, I'm trying to display the selected view controller like so: MainViewController().presentController(secondViewController). When this runs the currentController gets removed (revealing the Main View Controller's view which is just a black background) but the new controller doesn't get loaded in.
Can anyone guide me in the right direction?
Assuming that MainViewController is the name of your main view controller's class, the following line probably does not do what you intend:
MainViewController().presentController(secondViewController)
The MainViewController() will instantiate a new copy of the main view controller. I assume you meant to get a reference to the existing controller, not instantiate a new one.
Unrelated to your problem at hand, but you should not call willMoveToParentViewController before calling addChildViewController (because it does that for you). You only need to call didMoveToParentViewController when you're done configuring the new controller's view. Thus:
func presentController(controller: UIViewController) {
if currentController != controller {
if currentController != nil {
currentController!.willMoveToParentViewController(nil)
currentController!.view.removeFromSuperview()
currentController!.removeFromParentViewController()
}
// controller.willMoveToParentViewController(self)
self.addChildViewController(controller)
self.view.addSubview(controller.view)
controller.didMoveToParentViewController(self)
currentController = controller
}
}
I'm having a UISplitViewController that contains a UITabBarController as master view.
This UITabBarController contains a UINavigationController. The detail view contains a UINavigationController as well.
On the iPad this works as expected. The show detail segue presents the imageview within the navigation controller on the detail view.
On the iPhone on the other hand I expected that the show detail segue pushes the detail view on the stack of the navigation controller of the master view. But actually it is presented modally over the master view.
When removing the UITabBarController from the storyboard and using the UINavigationController directly in the master view this works.
Has anybody an idea how I could present the detail view on the stack of the master's UINavigationController on an iPhone?
The problem with Peter's solution is that it will fall apart with the iPhone 6 +. How so? With that code, if an iPhone 6 + is in portrait orientation - the detail view pushes onto the navigation stack. All is well, so far. Now, rotate into landscape, and then you'll have the detail view showing as the detail view and the master view.
You'll need the split view controller's delegate to implement two methods:
- (BOOL)splitViewController:(UISplitViewController *)splitViewController showDetailViewController:(UIViewController *)detailVC sender:(id)sender
{
UITabBarController *masterVC = splitViewController.viewControllers[0];
if (splitViewController.traitCollection.horizontalSizeClass == UIUserInterfaceSizeClassCompact)
[masterVC.selectedViewController showViewController:detailVC sender:sender];
else
[splitViewController setViewControllers:#[masterVC, detailVC]];
return YES;
}
And now, you'll need to return the top view controller from the selected tab's navigation controller:
- (UIViewController*)splitViewController:(UISplitViewController *)splitViewController separateSecondaryViewControllerFromPrimaryViewController:(UIViewController *)primaryViewController
{
UITabBarController *masterVC = splitViewController.viewControllers[0];
if ([(UINavigationController*)masterVC.selectedViewController viewControllers].count > 1)
return [(UINavigationController*)masterVC.selectedViewController popViewControllerAnimated:NO];
else
return nil; // Use the default implementation
}
With this solution, everything pushes onto the navigation stack when it should and also updates the detail view correctly on the iPad/6+ landscape.
I figured out how to put the detail on to the master's UINavigationController instead of presenting it modally over the UITabBarController.
Using the UISplitViewControllerDelegate method
- splitViewController:showDetailViewController:sender:
In case the UISplitViewController is collapsed get the masters navigation controller and push the detail view onto this navigation controller:
- (BOOL)splitViewController:(UISplitViewController *)splitViewController
showDetailViewController:(UIViewController *)vc
sender:(id)sender {
NSLog(#"UISplitViewController collapsed: %d", splitViewController.collapsed);
// TODO: add introspection
if (splitViewController.collapsed) {
UITabBarController *master = (UITabBarController *) splitViewController.viewControllers[0];
UINavigationController *masterNavigationController = (UINavigationController *)master.selectedViewController;
// push detail view on the navigation controller
//[masterNavigationController pushViewController:vc animated:YES];
// push was not always working (see discussion in answer below), use showViewController instead
[masterNavigationController showViewController:vc sender:sender];
return YES;
}
return NO;
}
The answer of #PeterOettl to his own question put me on the right way and is great for that. So the credit belongs to him.
I have nearly the same storyboard structure as him, but as vc is a navigationController I get a runtime error saying
'Pushing a navigation controller is not supported'
As said, that is because vc is the navigationController of the detail view and not the viewController of the detail view.
Note that I am surprised that #PeterOettl does not get that error in his case also, as the segue given in the storyboard picture, points to the navigation controller of the detail view.
Therefore the code should like that (in Swift) simply adding
let detailViewControllerNavigationController = (vc as UINavigationController).viewControllers[0] as UIViewController
and pushing detailViewControllerNavigationController instead of vc
and the whole code is
func splitViewController(splitViewController: UISplitViewController, showDetailViewController vc: UIViewController, sender: AnyObject?) -> Bool {
println("UISplitViewController collapsed: \(splitViewController.collapsed)")
if (splitViewController.collapsed) {
let master = splitViewController.viewControllers[0] as UITabBarController
let masterNavigationController = master.selectedViewController as UINavigationController
let detailViewControllerNavigationController = (vc as UINavigationController).viewControllers[0] as UIViewController
masterNavigationController.pushViewController(detailViewControllerNavigationController, animated: true)
return true
} else {
return false
}
}
Also note that this code is put in the AppDelegate.swift of the master-detail example of Xcode where a tab bar is added in the master view.
EDIT
In the comments we discussed with #PeterOettl of the difference between .pushViewController and .showViewController.
Apple documentation says :
showViewController:sender:
This method pushes a new view controller
onto the navigation stack in a similar way as the
pushViewController:animated: method. You can call this method directly
if you want but typically this method is called from elsewhere in the
view controller hierarchy when a new view controller needs to be
shown.
Available in iOS 8.0 and later.
I appreciate this discussion thread when I was implementing exactly the same UI structure app, and furthurmore made it adaptive for iPhone 6 Plus rotation and iPad multitasking (Slide Over/Split View, iOS 9 or later).
We have put the full solution (adaptive UISplitViewController with UITabBarController as primary view controller) open sourced on GitHub indievox-inc/TabBarSplitViewController. Thanks!
I implemented #Dreaming In Binary's answer in Swift:
func splitViewController(splitViewController: UISplitViewController, showDetailViewController vc: UIViewController, sender: AnyObject?) -> Bool {
let masterVC = splitViewController.viewControllers[0] as UITabBarController
if splitViewController.traitCollection.horizontalSizeClass == .Compact {
masterVC.selectedViewController?.showViewController(vc, sender: sender)
} else {
splitViewController.viewControllers = [masterVC, vc]
}
return true
}
func splitViewController(splitViewController: UISplitViewController, separateSecondaryViewControllerFromPrimaryViewController primaryViewController: UIViewController!) -> UIViewController? {
let masterVC = splitViewController.viewControllers[0] as UITabBarController
if let navController = masterVC.selectedViewController as? UINavigationController {
if navController.viewControllers.count > 1 {
return navController.popViewControllerAnimated(false)
}
}
return nil
}