backgroundQuality property
Rendering quality for the tab bar track/background container.
Matches UIKit's separation of UITabBarAppearance.backgroundEffect from
the system selection indicator pill:
- When null (default), inherits from quality (backward-compatible).
- When set, controls the quality tier of the track surface independently of the indicator pill. For example, setting backgroundQuality to GlassQuality.minimal or GlassQuality.standard while keeping quality at GlassQuality.premium delivers full Impeller chromatic refraction and jelly morphing on the indicator while saving GPU overhead on the static track.
Implementation
final GlassQuality? backgroundQuality;