Modal overlay views with orientation support

UIViewController+ZWDModalOverlay.h

//
//  UIViewController+ZWDModalOverlay.h
//
//  Created by Zoreslav Khimich on 28/01/2013.
//  Copyright (c) 2013 zrxq. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIViewController (ZWDModalOverlay)

- (void)presentModalOverlayViewController:(UIViewController *)modalOverlayViewController;
- (void)dismissModalOverlayViewController;

@end

UIViewController+ZWDModalOverlay.m

//
//  UIViewController+ZWDModalOverlay.m
//
//  Created by Zoreslav Khimich on 28/01/2013.
//  Copyright (c) 2013 zrxq. All rights reserved.
//

#import "UIViewController+ZWDModalOverlay.h"

static UIWindow *overlayWindow() {
    static UIWindow *overlayWindow = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        overlayWindow = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
        overlayWindow.backgroundColor = [UIColor clearColor];
        overlayWindow.windowLevel = UIWindowLevelAlert;
        overlayWindow.userInteractionEnabled = YES;
    });
    return overlayWindow;
}

@implementation UIViewController (ZWDModalOverlay)

- (void)presentModalOverlayViewController:(UIViewController *)modalOverlayViewController {
    UIWindow *window = overlayWindow();
    [window setRootViewController:modalOverlayViewController];
    [window makeKeyAndVisible];
}

- (void)dismissModalOverlayViewController {
    UIWindow *window = overlayWindow();
    [window resignKeyWindow];
    [window setHidden:YES];
    [window setRootViewController:nil];
}

@end