===== Auto-rotating a game =====

//Note: If you're using the Scaffold project of Sparrow 1.3 or 2.x, auto-rotation is already prepared for you. Find out all about it [[manual:The Scaffold Project|here]].//

If your game should support different orientations and be updated automatically when you rotate your device, that's easy to do. 

As described [[using_landscape_mode|here]], you achieve the best performance if you don't rotate the complete SPView, but only the content within Sparrow. Have a look at that tutorial to see how it's done.

==== Get notified of orientation changes ====

First, tell iOS that you want to be notified when the device's orientation changes. Put the following code in the init-method of your game class:

<code objc>
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
[[NSNotificationCenter defaultCenter] addObserver:self
    selector:@selector(onDeviceOrientationChanged:)
    name:@"UIDeviceOrientationDidChangeNotification" 
    object:nil];
</code>

==== React on those changes ====

Then add the following method to the same class:

<code objc>
- (void)onDeviceOrientationChanged:(UIEvent *)event 
{	
    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
    UIInterfaceOrientation interfaceOrientation = (UIInterfaceOrientation)deviceOrientation;
    
    // don't remove this, even if you're not displaying the status bar!
    // it has some positive side effects.
    [[UIApplication sharedApplication] setStatusBarOrientation:interfaceOrientation];
    
    // update your game contents here, as described above
    NSLog(@"Device Orientation changed: %i", deviceOrientation);
}
</code>

Whenever the device is now turned, that method gets called, and you can update the screen accordingly. //(Note that ''UIDeviceOrientationLeft'' corresponds to ''UIInterfaceOrientationRight''. Looks strange, but it's not an error.)//

If you want to support just a subset of those orientations, modify the method accordingly:

<code objc>
- (void)onDeviceOrientationChanged:(UIEvent *)event 
{	
    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
    
    if (deviceOrientation == UIDeviceOrientationPortrait ||
        deviceOrientation == UIDeviceOrientationPortraitUpsideDown)
    {
        // etc.
    }
}
</code>

That should do it!