How do I programmatically set device orientation i

Question

I am working on an iPad app, using AutoLayout, where if the user enables a certain mode ("heads-up" mode), I want to support only portrait (or portrait upside down) orientation, and furthermore, if the device is in landscape, I'd like to automatically switch to portrait mode.

In the top view controller, I have the following:

- (NSUInteger) supportedInterfaceOrientations {
    if (self.modeHeadsUp) {
        return UIInterfaceOrientationMaskPortrait | UIInterfaceOrientationMaskPortraitUpsideDown;
    } else {
        return UIInterfaceOrientationMaskAll;
    }
}

- (BOOL) shouldAutorotate {
    return TRUE;
}

Based on answers I've seen elsewhere here, the answer seems to be that I should use "application setStatusBarOrientation". Therefore, in the method where the user has selected "heads-up" mode, I have included:

    UIApplication *application = [UIApplication sharedApplication];
    [application setStatusBarOrientation:UIInterfaceOrientationPortrait
                                animated:YES];

However, this simply doesn't seem to do anything. While I can physically move the device to get it to rotate into portrait, it doesn't do so automatically.

In fact, when in landscape mode after running the above code to attempt to programmatically set the orientation, when I query the application "statusBarOrientation" with the following code, it remains at "4" for landscape:

UIApplication *application = [UIApplication sharedApplication];
int orientation = [application statusBarOrientation];
self.movesTextView.text = [NSString stringWithFormat:@"ORIENTATION %d", orientation];

It seemed like maybe autolayout wasn't being triggered with the setStatusBarOrientation, so I attempted to add this code after, to no effect:

    [super updateViewConstraints];
    [self.view updateConstraints];

I realize Apple wants to leave device orientation in the hands of the user. However, I'd like to be able to support landscape mode when not in "heads-up" mode.

Am I missing something to be able to force orientation change?

Answer 1

This solution lets you force a certain interface orientation, by temporarily overriding the value of UIDevice.current.orientation and then asking the system to rotate the interface to match the device's rotation:

Important: This is a hack, and could stop working at any moment

Add the following in your app's root view controller:

class RootViewController : UIViewController {
    private var _interfaceOrientation: UIInterfaceOrientation = .portrait
    override var supportedInterfaceOrientations: UIInterfaceOrientationMask { return UIInterfaceOrientationMask(from: _interfaceOrientation) }
    override var preferredInterfaceOrientationForPresentation: UIInterfaceOrientation { return _interfaceOrientation }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Register for notifications
        NotificationCenter.default.addObserver(self, selector: #selector(RootViewController.handleInterfaceOrientationChangeRequestedNotification(_:)), name: .interfaceOrientationChangeRequested, object: nil)
    }

    deinit { NotificationCenter.default.removeObserver(self) }

    func handleInterfaceOrientationChangeRequestedNotification(_ notification: Notification) {
        guard let interfaceOrientation = notification.object as? UIInterfaceOrientation else { return }
        _interfaceOrientation = interfaceOrientation
        // Set device orientation
        // Important:
        // • Passing a UIDeviceOrientation here doesn't work, but passing a UIInterfaceOrientation does
        // • This is a hack, and could stop working at any moment
        UIDevice.current.setValue(interfaceOrientation.rawValue, forKey: "orientation")
        // Rotate the interface to the device orientation we just set
        UIViewController.attemptRotationToDeviceOrientation()
    }
}

private extension UIInterfaceOrientationMask {

    init(from interfaceOrientation: UIInterfaceOrientation) {
        switch interfaceOrientation {
        case .portrait: self = .portrait
        case .landscapeLeft: self = .landscapeLeft
        case .landscapeRight: self = .landscapeRight
        case .portraitUpsideDown: self = .portraitUpsideDown
        case .unknown: self = .portrait
        }
    }
}

extension Notification.Name {
    static let interfaceOrientationChangeRequested = Notification.Name(rawValue: "interfaceOrientationChangeRequested")
}

Make sure all interface orientations are checked under "Deployment Info":

Request interface orientation changes where you need them:

NotificationCenter.default.post(name: .interfaceOrientationChangeRequested, object: UIInterfaceOrientation.landscapeRight)

Answer 2

Use this. Perfect solution to orientation problem..ios7 and earlier

[[UIDevice currentDevice] setValue:
    [NSNumber numberWithInteger: UIInterfaceOrientationPortrait]
        forKey:@"orientation"];

Answer 3

NSNumber *value = [NSNumber numberWithInt:UIInterfaceOrientationLandscapeLeft]; [[UIDevice currentDevice] setValue:value forKey:@"orientation"];

does work but you have to return shouldAutorotate with YES in your view controller

- (BOOL)shouldAutorotate
{
    return self.shouldAutoRotate;
}

But if you do that, your VC will autorotate if the user rotates the device... so I changed it to:

@property (nonatomic, assign) BOOL shouldAutoRotate;

- (BOOL)shouldAutorotate
{
    return self.shouldAutoRotate;
}

and I call

- (void)swithInterfaceOrientation:(UIInterfaceOrientation)orientation
{
    self.rootVC.shouldAutoRotate = YES;

    NSNumber *value = [NSNumber numberWithInt: orientation];
    [[UIDevice currentDevice] setValue:value forKey:@"orientation"];
}

to force a new orientation with a button-click. To set back shouldAutoRotate to NO, I added to my rootVC

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
    self.shouldAutoRotate = NO;
}

PS: This workaround does work in all simulators too.

Answer 4

The base UINavigationController should have the below callback so that the child items can decide what orientation they want.

-(NSUInteger)supportedInterfaceOrientations {
    UIViewController *topVC = self.topViewController;
    return topVC.supportedInterfaceOrientations;
}

-(BOOL)shouldAutorotate {
   UIViewController *topVC = self.topViewController;
   return [topVC shouldAutorotate];
}

Answer 5

I was in a similar problem than you. I need to lock device orientation for some screens (like Login) and allow rotation in others.

After a few changes and following some answers below I did it by:

• Enabling all the orientations in the Project's Info.plist.

• Disabling orientation in those ViewControllers where I need the device not to rotate, like in the Login screen in my case. I needed to override shouldAutorotate method in this VC:

-(BOOL)shouldAutorotate{ return NO; }

Hope this will work for you.

Answer 6

You need to call attemptRotationToDeviceOrientation (UIViewController) to make the system call your supportedInterfaceOrientations when the condition has changed.