How do I rotate custom splash screen on iOS?

Question

My splash screen is working, but my app works on landscape mode, and the splash screen shows in the default portrait mode.

How can I start the app so that the splash screen rotates between landscape modes like my app?

I'm using the following code:

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Overriden to allow any orientation.
if (interfaceOrientation == UIInterfaceOrientationLandscapeLeft ||
    interfaceOrientation == UIInterfaceOrientationLandscapeRight)
    return YES;
else {
    return NO;  }
}

and for the splash screen

-(void)displayScreen { 
UIViewController *displayViewController=[[UIViewController alloc] init];
displayViewController.view = displaySplashScreen;
[self presentModalViewController:displayViewController animated:NO];
[self performSelector:@selector(removeScreen) withObject:nil afterDelay:3.0];
} 
 -(void)removeScreen
{   [[self modalViewController] dismissModalViewControllerAnimated:YES];
}

But how can I put the rotate inside the display screen?

Answer 1

Aha. If you want to display your own splash screen, you should create a special view controller for that, which you already did. I think you can simplify the autorotation query code:

- (BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation) foo
{
    return YES; // all interface orientations supported
}

Now you have to think about the splash screens for different orientations. Do you have a separate splash image for landscape and portrait? If yes, you can do something like this:

- (UIView*) startupImageWithOrientation: (UIInterfaceOrientation) io
{
    UIImage *img = [UIImage imageNamed:[NSString
        stringWithFormat:@"Default-%@.png", UIInterfaceOrientationName(io)]];
    UIView *view = [[UIImageView alloc] initWithImage:img];
    [view setFrame:[[UIScreen mainScreen] applicationFrame]];
    return [view autorelease];
}

- (void) loadView
{
    self.view = [self startupImageWithOrientation:self.interfaceOrientation];
}

- (void) willRotateToInterfaceOrientation: (UIInterfaceOrientation) io
    duration: (NSTimeInterval) duration
{
    self.view = [self startupImageWithOrientation:io];
    self.view.transform = CGAffineTransformFromUIOrientation(io);
}

There are two utility functions called, you can stuff these into a separate file:

NSString *UIInterfaceOrientationName(UIInterfaceOrientation io)
{
    return UIInterfaceOrientationIsPortrait(io) ? @"Portrait" : @"Landscape";
}

CGAffineTransform CGAffineTransformFromUIOrientation(UIInterfaceOrientation io)
{
    assert(io <= 4);
    // unknown, portrait, portrait u/d, landscape L, landscape R
    static float angles[] = {0, 0, M_PI, M_PI/2, -M_PI/2};
    return CGAffineTransformMakeRotation(angles[io]);
}

It’s a bit messy, I’d be interested in simpler solution myself.