BlurryModalSegue

BlurryModalSegue is a UIStoryboardSegue subclass that provides a blur effect for modal storyboard segues. It provides the look and feel of a transparent modal overlay without deviating from the modal presentation model provided by Apple.

Demo

Installation

Via CocoaPods:

pod 'BlurryModalSegue'

Usage

Storyboard Usage

Change your modal storyboard segues from this:

To this:

Done!

If nested view controllers are being presented (e.g., UINavigationController -> UIViewController), make sure to set the background color of any nested views to [UIColor clearColor] so the blurry UIImageView is visible

Custom Styling

BlurryModalSegue conforms to the UIAppearance protocol. Configure it once across the app:

#import "BlurryModalSegue.h"

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [[BlurryModalSegue appearance] setBackingImageBlurRadius:@(20)];
    [[BlurryModalSegue appearance] setBackingImageSaturationDeltaFactor:@(.45)];
    
    return YES;
}

Additionally, you can customize individual instances before presentation, just implement prepareForSegue:sender::

#import "BlurryModalSegue.h"

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue isKindOfClass:[BlurryModalSegue class]])
    {
        BlurryModalSegue* bms = (BlurryModalSegue*)segue;
        
        bms.backingImageBlurRadius = @(20);
        bms.backingImageSaturationDeltaFactor = @(.45);
        bms.backingImageTintColor = [[UIColor greenColor] colorWithAlphaComponent:.1];
    }
}

Troubleshooting

If you just see a solid color instead of a blurry background after performing a segue, ensure that the view controllers being presented don't have a background color set on their views. This is common when presenting a UINavigationController that is in turn presenting a root view controller. The UIImageView that contains the blurry image is added as a subview to the -[UIStorybardSegue destinationViewController]'s view property. In the case of a presented UINavigationController, it immediately presents a child view controller. If that view controller has a solid background color, it could completely hide the blurry UIImageView.

Compatibility/Restrictions

iOS7+ only, as we take advantage of the new UIViewControllerTransitionCoordinator.
UIModalTransitionStylePartialCurl is not supported and doesn't really make sense for this library.
For UIModalTransitionStyleCoverVertical, eagle-eyed developers will notice that the effect is better during presentation than dismissal. This is because [UIViewController -transitionCoordinator] only seems to support the presentation, not the dismissal. I believe the dismissal could be implented using the [UIViewController -transitioningDelegate], but that is TBD.
Rotation after modal presentation is unsupported as the backing image will only be appropriate for the original orientation.

Acknowledgements

The blur effect in this library is courtesy of the UIImage-BlurredFrame library.

Citrrus/BlurryModalSegue