How to implement UIViewController rotation in response to orientation changes?

Question

My app has about 10 different UIViewControllers, just one of which I want to switch to landscape mode if the device is rotated. (All the rest, I want to keep in portrait.)

Answer 1

I have seen examples using the way you are doing it but couldn't get it to work properly. I found the better way to do it from Apples examples. Basically you implement a presentModalViewController and create another view. UIKit does a basic rotation animation and fades between the view. You have to implement the rotated view as a delegate class so it can call back to its calling class to dismiss it and update the orientation.

- (void)orientationChanged:(NSNotification *)notification
{
    // We must add a delay here, otherwise we'll swap in the new view
    // too quickly and we'll get an animation glitch
    NSLog(@"orientationChanged");
    [self performSelector:@selector(updateLandscapeView) withObject:nil afterDelay:0];
}

And then to display a landscape screen:

- (void)updateLandscapeView
{
PortraitView *portraitView = [[PortraitView alloc] init];
portraitView.delegate = self;
UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
if (UIDeviceOrientationIsLandscape(deviceOrientation) && !isShowingLandscapeView)
{
    [self presentModalViewController: portraitView animated:YES];
    isShowingLandscapeView = YES;
    }
else if (deviceOrientation == UIDeviceOrientationPortrait && isShowingLandscapeView)
{
    [self dismissModalViewControllerAnimated:YES];
    isShowingLandscapeView = NO;
    }
[portraitView release];
}