UIInterfaceOrientation bug? - iphone

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.

Answer 3

I would recommend using UIDeviceOrientationIsValidInterfaceOrientation(orientation)
It will tell you if its a valid orientation (valid being either landscape or portrait, not FaceUp/FaceDown/UnKnown). Then you can treat it as if its portrait if its unknown.
This is how I do it:
if (UIDeviceOrientationIsValidInterfaceOrientation(interfaceOrientation) && UIInterfaceOrientationIsLandscape(interfaceOrientation)) {
// handle landscape
} else {
// handle portrait
}