Original research and demo of _UIProgressiveBlurPresentationController
Progressive Blur
In iOS 12, Apple added _UIProgressiveBlurPresentationController to UIKit. I noticed it a while back but had no idea how to implement it, lol. Recently, after learning how modal presentations work, I realized I would be able to finally see what this is. While grabbing a header for it, I happened to find that it’s used in TVMLKit, which would explain why the animation is so fancy.
The transition delegate, _UIProgressiveBlurContextController, is all you need. It has a property/ivar called blurStyle. It seems to have values up to 2. I suspect the type is something like:
.default(which appears to be1).light.dark
I highly suggest switching device appearance to not match the blur style to see how the effect works.
For further research, delve into runtime headers for the four _UIProgressiveBlur headers or check out TVMLKit’s TVModalPresenter.
Enjoy!