Detect landscape to landscape orientation change

Question

I do some custom layout including an animation in willAnimateRotationToInterfaceOrientation:duration: The problem I have is that if the device changes from landscapeLeft to landscapeRight the interface should rotate but the layout code, especially the animation should not be run. How can I detect that it is changing from one landscape to another? self.interfaceOrientation as well as [[UIApplication sharedApplication] statusBarOrientation] don't return valid results, they seem to think the device is already rotated. As a result the following does not work .

if (UIInterfaceOrientationIsLandscape(toInterfaceOrientation) && UIInterfaceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation]) {...}

Answer 1

You can check the device orientation and then set a flag as to whether you are in left orientation or right orientation. Then when your device switches you can catch it and handle it however you want.

To determine orientation use:

if([UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft)
{
    //set Flag for left
}
else if([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight)
{
    //set Flag for right
}

You can also catch a notification when the device is rotating using:

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(detectOrientation) name:@"UIDeviceOrientationDidChangeNotification" object:nil];

And then write a method for detectOrientation like so:

-(void) detectOrientation 
{
    if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft)
    {
        //Set up left
    } else if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight)
    {
        //Set up Right
    } else if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown) 
    {
        //It's portrait time!
    }   
}

Answer 2

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
 {
   if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft || [[UIDevice currentDevice] orientation ]== UIDeviceOrientationLandscapeRight)
    {
      NSLog(@"Lanscapse");
    }
   if([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait || [[UIDevice currentDevice] orientation] == UIDeviceOrientationPortraitUpsideDown )
    {
      NSLog(@"UIDeviceOrientationPortrait");
    }
 }

Answer 3

It seems that the only solution is to cache the last orientation change. By the time willAnimateRotationToInterfaceOrientation: is called the device and interface orientations have already been updated. The solution is to record the destination orientation at the end of each change so that this value can be queried when the orientation is set to change again. This is not as elegant as I was hoping (yet another property on my view controller) but seems to be the only way as far as I can tell.