This UIView subclass demonstrates how Apple does realtime blurring in iOS 7. This class uses private APIs and thus should not be used in production.
Here is how it works:
- The view is backed by a
CABackdropLayer, which takes its contents from the layers behind it. This class is new to iOS 7. - A Gaussian blur
CAFilteris applied to the view's layer. This filter has existed since iOS 3. The only recent addition is the ability to degrade the quality of the blur (scale down the layer content before blurring), to increase performance. - This implementation is very minimal, so it does not include additional color filters as Apple's implementation does.
CKBlurView is available under the MIT license. See the LICENSE file for more info.