Apply a rounded overlay to a viewcontroller.

UIView+RoundedOverlay.h

//
//  UIView+RoundedOverlay.h
//
//  Created by Tom Adriaenssen on 05/04/12.
//

#import <UIKit/UIKit.h>

@interface UIViewController (RoundedOverlay)

- (void)applyRoundedOverlay;

@end

UIView+RoundedOverlay.m

//
//  UIView+RoundedOverlay.m
//
//  Created by Tom Adriaenssen on 05/04/12.
//

#import "UIViewController+RoundedOverlay.h"
#import <QuartzCore/QuartzCore.h>

#define TAG 86456134

@implementation UIViewController (RoundedOverlay)


- (void)applyRoundedOverlay {
    UIView* selfView = self.navigationController ? self.navigationController.view : self.view;
    
    UIImageView* view = (UIImageView*)[selfView viewWithTag:TAG];
    if (!view) {
        UIImage* image = [UIImage imageNamed:@"rounded-overlay.png"];
        image  = [[self image:image cropped:(CGRect) { 0, 0, image.size.width, 5 }] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];
        view = [[UIImageView alloc] initWithImage:image];
        
        view.layer.shouldRasterize = YES;
        view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin;
        view.tag = TAG;
        view.userInteractionEnabled = NO;
    }
    else
        [view removeFromSuperview];
    
    view.frame = (CGRect) { 0, 0, selfView.bounds.size.width, 5 };
    if (selfView.superview == nil || ([selfView.superview.superview isKindOfClass:[UIWindow class]] && selfView.superview.frame.origin.y == 0)) {
        view.frame = CGRectOffsetTopAndShrink(view.frame, [[UIApplication sharedApplication] statusBarFrame].size.height);
    }
    
    [selfView addSubview:view];

    view = (UIImageView*)[selfView viewWithTag:TAG+1];
    if (!view) {
        UIImage* image = [UIImage imageNamed:@"rounded-overlay.png"];
        image  = [[self image:image cropped:(CGRect) { 0, image.size.height-5, image.size.width, 5 }] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 5, 0, 5)];
        view = [[UIImageView alloc] initWithImage:image];
        
        view.layer.shouldRasterize = YES;
        view.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleBottomMargin;
        view.tag = TAG+1;
        view.userInteractionEnabled = NO;
    }
    else
        [view removeFromSuperview];
    
    view.frame = (CGRect) { 0, selfView.bounds.size.height-5, selfView.bounds.size.width, 5 };   
    [selfView addSubview:view];
}


- (UIImage*)image:(UIImage*)image cropped:(CGRect)cropRect {
    if (image.scale != 1.0f) {
        cropRect = CGRectMake(cropRect.origin.x * image.scale,
                              cropRect.origin.y * image.scale,
                              cropRect.size.width * image.scale,
                              cropRect.size.height * image.scale);
    }
    CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
    image = [UIImage imageWithCGImage:imageRef scale:image.scale orientation:image.imageOrientation];
    CGImageRelease(imageRef);
    return image;
}
                
@end