[Android] Haze area isn't invalidated on overscroll

[poliver]

The haze area doesn't get invalidated when a haze child is stretched/moved due to an overscroll.

Screen_recording_20231220_004023.mp4

[chrisbanes]

Thanks for the report. Yeah I've notice the same, but I'm not sure there's much we can do here. The stretch overscroll effect is implemented via a Skia ImageFilter underneath (iirc), so I've got a feeling that they're just not going to work together.

I'll ask some of the Android graphics folks and see what they say.

[chrisbanes]

The stretch overscroll is implemented as an effect on the scrollable UI element. In this case, the LazyColumn is stretched. Haze works by telling a background element were to blur itself, meaning that the stretch effect isn't happening to the blurred background element, and thus no effect. For Haze to be part of the stretch overscroll, you need to use the Modifier.haze() on the scrollable container itself.