UIInterfaceOrientation bug ?

Question

In my iPhone app I need to detect the current orientation and I have to determine if I'm in portrait or landscape. I use this code:

UIInterfaceOrientation orientation = [[UIDevice currentDevice] orientation];
if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) {
     NSLog(@"portrait");
     ...
} else {
     NSLog(@"landscape");
     ...
}

Everything is ok when my iPhone is in my hand. But when i put it on the table and i run the application, the content is displayed on the screen in portrait mode and my code goes to else and NSLog prints landscape.

Is my test incomplete ? How to prevent this case ?

EDIT : the test is performed in my controller viewDidLoad method and my application handle rotation.

Answer 1

UIDevice.orientation is of type UIDeviceOrientation, which is a superset of UIInterfaceOrientation. You are probably getting the value UIDeviceOrientationFaceUp.

This underscores that yes, your test is incomplete. You should write something like this:

UIInterfaceOrientation orientation = [[UIDevice currentDevice] orientation];
if (orientation == UIInterfaceOrientationPortrait || orientation == UIInterfaceOrientationPortraitUpsideDown) {
     NSLog(@"portrait");
     ...
} else if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) {
     NSLog(@"landscape");
     ...
} else {
     NSLog(@"WTF? %d", orientation);
     assert(false);
}

Then, you'll know if you if you've missed something.

Answer 2

UIDevice.orientation can return that the device is flat or upside down (not inverted portrait, upside-down as in laying on its face). Instead call UIViewController.interfaceOrientation on your root view controller.