crossExtent property

double get crossExtent

Thickness of the shell across the bar: its height in a horizontal bar, its width in the vertical strip.

A group that shares with nothing is the circular button iOS 26 draws for a lone bar item — at that height the capsule's borderRadius is clamped to exactly half the box, so the rounded rectangle is a circle. A shared capsule keeps the 2pt taller icon-slot height it has always had. In the strip every control is GlassVerticalBarMetrics.controlExtent wide.

Implementation

double get crossExtent {
  if (axis == Axis.vertical) return GlassVerticalBarMetrics.controlExtent;
  final diameter = buttonSize ?? GlassNavPinnedMetrics.backDiameter;
  return background == GlassBarItemBackground.shared
      ? diameter +
          (GlassNavPinnedMetrics.slot - GlassNavPinnedMetrics.backDiameter)
      : diameter;
}