public final class GlassRecipe

A typed, named recipe for the “Liquid Glass” backdrop materials (iOS 26).

A glass surface is described by its material INTENT – which named recipe it uses – rather than by loose per-parameter theme constants. Each recipe bundles the bounded, measured parameters of one native material (the colour transform the real UIVisualEffectView / UIGlassEffect applies to the blurred backdrop, plus the edge optics), so similar glass surfaces cannot silently diverge and a theme cannot tune itself into an incoherent material. The available recipes:

• blur – Kind.PLAIN_BLUR: backdrop blur only, no material colour transform (a plain CSS backdrop-filter).
• chrome – Kind.LIQUID_CHROME: the rectangular chrome bars anchored at a screen edge (navigation / title bars). Very transparent; the backdrop reads through at near-full saturation.
• pill – Kind.LIQUID_PILL: the floating pill chrome (the iOS 26 tab bar). Frostier than the edge bars – in light mode it washes strongly toward white while boosting saturation.
• panel – Kind.LIQUID_PANEL: a bare glass panel or button capsule (UIGlassEffect). The strongest material: heavy wash, plus edge refraction and a specular rim so the glass reads as a layer on top of the content rather than a flat hole.

A theme assigns a recipe per UIID with the theme constant <UIID>GlassRecipe (for example ToolbarGlassRecipe: chrome), with glassRecipeDefault as the theme-wide default (panel when unset). The recipe is resolved at paint time by Component.internalPaintImpl and its parameters are passed to the port through Graphics.glassRegion; ports never read material constants themselves.

The travelling tab-selection lens is the remaining glass surface; it is an optics-over-content effect bound to the morph motion, so its typed parameters live with the motion model (TabSelectionMorph) rather than here.