Module shadow 

Layered drop-shadow helper for elevated surfaces.

Composes two [Shadow]s underneath a rounded rect:

• outer — the wide soft halo (typically theme.shape.shadow_*).
• inner — the sharp short-blur rim that gives the surface a clearly “lifted” edge instead of a vague glow (typically the matching theme.shape.shadow_inner_*).

The inner token’s geometry (offset_y, blur, color.rgb) is used verbatim. Only color.a is modulated: the painted alpha is density × inner.color.a(), with density ∈ [0.0, 1.0] provided by the per-component shadow_density field. This keeps every visual knob in the theme while letting individual surfaces dial intensity.

Common density presets:

• 1.0 — tooltips (full inner-rim alpha, punchy “lift”).
• ~0.5 — cards, popovers, menus (moderate).
• 0.0 — disable inner rim entirely (single-layer outer only).

Attached side

Popovers, menus and combo-box dropdowns sit attached to the widget that opened them. On the side that touches the trigger, drawing a halo would visually cut the surface off from its anchor. Pass an AttachedSide to suppress shadow on that side.

// Typical usage inside a custom widget's paint() method:
use teksilo_widgets::shadow::{paint_layered_shadow, DENSITY_SURFACE};
paint_layered_shadow(
    canvas, bounds, radius,
    &ctx.theme.shape.shadow_sm,
    &ctx.theme.shape.shadow_inner_sm,
    DENSITY_SURFACE,
    None,
);

Enums

AttachedSide

Which geometric edge of the surface is attached to its trigger and should have shadow drawing suppressed on that side. Geometric (Top / Bottom / Left / Right), not RTL-aware — callers working in Leading/Trailing terms must resolve to a geometric side using the active layout direction before calling.

Constants

DENSITY_DIALOG

Inner-rim alpha multiplier for snackbars and dialogs — subtle lift.

DENSITY_SURFACE

Inner-rim alpha multiplier for cards, popovers, and menus — moderate lift.

DENSITY_TOOLTIP

Inner-rim alpha multiplier for tooltips — full intensity for maximum lift.

Functions

paint_layered_shadow

Paint a two-layer drop shadow behind a rounded rect.