How do launchers change the shape of an adaptive icon, including removal of background?

Question

Background

Starting from Android O, apps can have adaptive icons, which are 2 layers of drawables: foreground and a background. The background is a mask that gets

Answer 1

Since Launcher is just an Activity, you can draw anything. You can draw application icons like ponies that run on beautiful animated clouds. This is your world, which obeys only your rules.

Further ... There is no magic in the programming world. If you are faced with magic, just use decompilers (with Java it very easy), find the code responsible for magic, document it and write a great blog post about how this magic works.

Given a AdaptiveIconDrawable instance, how do you shape it, to be of a circular shape, rectangle, rounded rectangle, tear, and so on?

You can use AdaptiveIconDrawable.getBackground() and add any mask to it. Actually, you can do anything what you want with icon, AdaptiveIconDrawable is just way, where you can split foreground and background in easy way, without complicated filters or neural networks. Add parallax, animations and many more effects, now you have 2 layer for it.