Hide screen when iOS app resigns active

hideScreen.m

@interface KIDAppDelegate ()
@property (nonatomic, strong) UIViewController *hideInformationViewController;
@end

@implementation KIDAppDelegate
{

- (void)applicationWillResignActive:(UIApplication *)application
{
    [self hideScreen:YES];
}

- (void)applicationDidBecomeActive:(UIApplication *)application
{
    [self hideScreen:NO];
}

- (void)hideScreen:(BOOL)hide
{
    // This causes a crash on iOS 7, when the app is currently transitioning to a modal view controller.
    // On iOS 8, this doesn't crash the app, but it's unreliable whether it actually hides the transitioning view controller.
    // Doesn't work in Simulator when you put the app directly in the background. If you go through app switcher it works fine. Works fine on device.
    
    if (hide) {
        UIViewController *topmostViewController = self.window.rootViewController;
        while (topmostViewController.presentedViewController) {
            topmostViewController = topmostViewController.presentedViewController;
            if ([topmostViewController isKindOfClass:[UINavigationController class]] && !topmostViewController.presentedViewController) {
                topmostViewController = [(UINavigationController *)topmostViewController visibleViewController];
            }
        }
        
        self.hideInformationViewController = [UIViewController new];
        UIImage *image = [UIImage imageNamed:@"LaunchImage-700-568h"];
        UIImageView *hideImageView = [[UIImageView alloc] initWithImage:image];
        hideImageView.contentMode = UIViewContentModeTop;
        hideImageView.frame = self.window.bounds;
        self.hideInformationViewController.view = hideImageView;
        
        [topmostViewController presentViewController:self.hideInformationViewController animated:NO completion:nil];
    }
    else {
        if (self.hideInformationViewController) {
            [self.hideInformationViewController dismissViewControllerAnimated:NO completion:nil];
            self.hideInformationViewController = nil;
        }
    }
}

}