Disable rotation in UIImagePicker

Question

Hello I need to disable the rotation of the UIImagePicker.
If the user takes picture when the iPhone is on "landscape" the buttons will rotate and the picture taken will also be rotated. I want to disable that option so the accelerometer will not work and it will always take picture like in portrait mode.
How can I do that?
Thanks, Matan Radomski.

Answer 1

Here's the solution: [UIDevice endGeneratingDeviceOrientationNotifications].

Why was it so hard to find? Two reasons:

1. The UIDevice keeps count of how many times orientation notifications are switched on or off. If it has been switched on more times than it's been switched off, notifications will still be issued.
2. The UIImagePickerController switches these notifications on when it is presented.

So, calling this method once did nothing to the image picker. To make sure orientation notifications are off and stay off, you need to switch them off before and after the picker is presented.

This does not affect iOS or other apps. It doesn't even fully affect your own app: as with the other method I suggested, the camera buttons continue responding to orientation changes, and the photos taken are also orientation aware. This is curious, because the device orientation hardware is supposed to be switched off if it isn't needed.

@try 
{
    // Create a UIImagePicker in camera mode.
    UIImagePickerController *picker = [[[UIImagePickerController alloc] init] autorelease]; 
    picker.sourceType = UIImagePickerControllerSourceTypeCamera;  
    picker.delegate = self; 

    // Prevent the image picker learning about orientation changes by preventing the device from reporting them.
    UIDevice *currentDevice = [UIDevice currentDevice];

    // The device keeps count of orientation requests.  If the count is more than one, it continues detecting them and sending notifications.  So, switch them off repeatedly until the count reaches zero and they are genuinely off.
    // If orientation notifications are on when the view is presented, it may slide on in landscape mode even if the app is entirely portrait.
    // If other parts of the app require orientation notifications, the number "end" messages sent should be counted.  An equal number of "begin" messages should be sent after the image picker ends.
    while ([currentDevice isGeneratingDeviceOrientationNotifications])
        [currentDevice endGeneratingDeviceOrientationNotifications];

    // Display the camera.
    [self presentModalViewController:picker animated:YES];

    // The UIImagePickerController switches on notifications AGAIN when it is presented, so switch them off again.
    while ([currentDevice isGeneratingDeviceOrientationNotifications])
        [currentDevice endGeneratingDeviceOrientationNotifications];
}
@catch (NSException *exception) 
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"No Camera" message:@"Camera is not available" delegate:self cancelButtonTitle:@"Ok" otherButtonTitles:nil];
    [alert show];
    [alert release];
}

As noted above, the pictures taken may still be in the wrong orientation. If you want them oriented consistently, check their aspect ratio and rotate accordingly. I recommend this answer to How to Rotate a UIImage 90 degrees?

//assume that the image is loaded in landscape mode from disk
UIImage * landscapeImage = [UIImage imageNamed: imgname];
UIImage * portraitImage = [[UIImage alloc] initWithCGImage: landscapeImage.CGImage scale:1.0 orientation: UIImageOrientationLeft] autorelease];

Answer 2

Back in 2010, How to prevent a modal UIImagePickerController from rotating? found no happy answer to this question.

I found an alternative, but it's also like to get you rejected from the App Store: remove all observers from the window.

If some part of your app outside a viewController needs orientation change messages, it can register for them:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:[UIDevice currentDevice]];

The window, not surprisingly, registers for such notifications, then rotates the view controllers if they accept the new orientation. It's not conveniently watching for UIDeviceOrientationDidChangeNotification, so there must be a privately named equivalent. All you can do is remove every notification from the window:

[[NSNotificationCenter defaultCenter] removeObserver:[[self view] window]];

There is no restoring this, if you just wanted to temporarily suppress orientation changes. Neither can we tell if the window was watching for any important notifications from other sources. It's incomplete, too - the button for turning over, and the button for taking a photo, move and rotate on their own.

How can you fix that quirk? You could switch off showsCameraControls on the UIImagePicker, and provide your own cameraOverlayView with the camera buttons on it. Or continue randomly removing notifications by traversing an entire view hierarchy (also rejection material) removing notifications from everything:

- (void) removeAllNotificationsFromView:(UIView*) view;
{
    // This recurses through the view hierarchy removing all notifications for everything.
    // This is potentially destructive, and may result in rejection from the App Store.
    [[NSNotificationCenter defaultCenter] removeObserver:view];
    for (UIView *subview in [view subviews])
        [self removeAllNotificationsFromView:subview];
}

[self removeAllNotificationsFromView:imagePicker.view];

I don't recommend using this, but it provides some interesting insights into how orientation changes are detected and propagated.

Answer 3

None of the above solutions worked for me. What worked is this (for iOS 7 that i have tested it on)-

1. Subclass UIImagePickerController

2. Override shouldAutorotate method and return NO.

    -(BOOL)shouldAutorotate
    {
        return NO;
    }

Answer 4

Add following code to your view

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation 
{
     return NO;
}