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:

- (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::

- (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.