Switch container view dynamically - objective-c

Question

I'm using a storyboard container view. So I have a view controller containing a container view. I have a second, smaller view in the storyboard, which is embedded in that container via an embed segue. So far so good.
Now I would like to be able to switch the contents of that container view dynamically, when the user taps a button. The button will be on the main, larger, view. I have made another view controller of the same smaller size, and given it a different storyboard ID.
However, I can't work out how to code the switch. I can only create a single embed segue for that container.
Any help gratefully received.

Answer 1

You need to use the custom container view controller api to do the switching of the controllers. The following code shows one way to do that. In this project I had a segmented control in the main view controller (the one with the container view) that switches beetween the two controllers. initialVC is the controller that's embedded in IB, and substituteVC is the one I'm switching to. The property, container, is an IBOutlet to the container view.
- (void)viewDidLoad {
[super viewDidLoad];
self.initialVC = self.childViewControllers.lastObject;
self.substituteVC = [self.storyboard instantiateViewControllerWithIdentifier:#"Substitute"];
self.currentVC = self.initialVC;
}
-(IBAction)switchControllers:(UISegmentedControl *)sender {
switch (sender.selectedSegmentIndex) {
case 0:
if (self.currentVC == self.substituteVC) {
[self addChildViewController:self.initialVC];
self.initialVC.view.frame = self.container.bounds;
[self moveToNewController:self.initialVC];
}
break;
case 1:
if (self.currentVC == self.initialVC) {
[self addChildViewController:self.substituteVC];
self.substituteVC.view.frame = self.container.bounds;
[self moveToNewController:self.substituteVC];
}
break;
default:
break;
}
}
-(void)moveToNewController:(UIViewController *) newController {
[self.currentVC willMoveToParentViewController:nil];
[self transitionFromViewController:self.currentVC toViewController:newController duration:.6 options:UIViewAnimationOptionTransitionFlipFromLeft animations:nil
completion:^(BOOL finished) {
[self.currentVC removeFromParentViewController];
[newController didMoveToParentViewController:self];
self.currentVC = newController;
}];
}
After Edit:
If you want to go to the new controller with no animation, you can do it like this (this substitutes for the code that I had under case 1).
[self addChildViewController:self.substituteVC];
[self.substituteVC didMoveToParentViewController:self];
self.substituteVC.view.frame = self.container.bounds;
[self.container addSubview:self.substituteVC.view];
[self.currentVC removeFromParentViewController];

Answer 2

rdelmar's answer converted to Swift syntax
override func viewDidLoad() {
super.viewDidLoad()
self.initialVC = self.childViewControllers.last
self.substituteVC = self.storyboard!.instantiateViewControllerWithIdentifier("Substitute")
self.currentVC = self.initialVC;
}
#IBAction func switchControllers(sender: UISegmentedControl) {
switch sender.selectedSegmentIndex{
case 0:
if (self.currentVC == self.substituteVC) {
self.addChildViewController(self.initialVC)
//self.initialVC.view.frame = self.containerView.bounds
moveToNewController(self.initialVC)
}
case 1:
if (self.currentVC == self.initialVC) {
self.addChildViewController(self.substituteVC)
//self.substituteVC.view.frame = self.containerView.bounds
moveToNewController(self.substituteVC)
}
default:
break;
}
}
func moveToNewController(newController : UIViewController){
self.currentVC.willMoveToParentViewController(nil)
self.transitionFromViewController(
self.currentVC!,
toViewController: newController,
duration: 0.2,
options: UIViewAnimationOptions.TransitionCrossDissolve,
animations: nil,
completion: { finished in
self.currentVC.removeFromParentViewController()
newController.didMoveToParentViewController(self)
self.currentVC = newController
})
}

Answer 3

If you deal with more than 2 child view controllers it's a good idea to store them in array. Also, you'll need to apply constraints every time you add a new subview to the container view. Here's a modified version of the accepted answer (using Swift 2 syntax):
import UIKit
class FooBarViewController: UIViewController
{
// MARK: - IBOutlets
#IBOutlet weak var containerView: UIView!
// MARK: - Properties
var vcs = [UIViewController]()
var currentVC: UIViewController!
// MARK: - ViewController Lifecycle
override func viewDidLoad()
{
super.viewDidLoad()
vcs.append(childViewControllers.last!)
vcs.append(storyboard!.instantiateViewControllerWithIdentifier("FooViewControler"))
vcs.append(storyboard!.instantiateViewControllerWithIdentifier("BarViewController"))
currentVC = vcs[0]
for vc in vcs {
vc.view.frame = containerView.bounds
}
}
// MARK: - Methods
func switchToViewController(targetVC: UIViewController)
{
addChildViewController(targetVC)
currentVC.willMoveToParentViewController(nil)
transitionFromViewController(
currentVC,
toViewController: targetVC,
duration: 0.0, // 0.3
options: .TransitionNone, // .TransitionCrossDissolve,
animations: nil,
completion: { finished in
self.currentVC.removeFromParentViewController()
targetVC.didMoveToParentViewController(self)
self.currentVC = targetVC
self.applyConstraints()
})
}
func applyConstraints()
{
let viewsDict = ["newSubview": currentVC.view]
currentVC.view.translatesAutoresizingMaskIntoConstraints = false
containerView.addConstraints(
NSLayoutConstraint.constraintsWithVisualFormat("H:|[newSubview]|",
options: NSLayoutFormatOptions(rawValue: 0),
metrics: nil,
views: viewsDict))
containerView.addConstraints(
NSLayoutConstraint.constraintsWithVisualFormat("V:|[newSubview]|",
options: NSLayoutFormatOptions(rawValue: 0),
metrics: nil, views:
viewsDict))
}
// MARK: - IBActions
#IBAction func switchControllers(sender: UISegmentedControl)
{
let i = sender.selectedSegmentIndex
if currentVC != vcs[i] {
self.addChildViewController(vcs[i])
switchToViewController(vcs[i])
}
}
}