defaultQuality property
Default quality hint for descendants that don't specify explicit quality.
When set, GlassThemeHelpers.resolveQuality uses this as the fallback
instead of GlassQuality.standard. This allows bar surfaces to default
all their children to premium quality without requiring explicit
quality: GlassQuality.premium on each widget.
GlassAdaptiveScope ceiling still caps this on low-end devices.
Implementation
final GlassQuality? defaultQuality;