build method

@override Widget build(BuildContext context)

Describes the part of the user interface represented by this widget.

The framework calls this method when this widget is inserted into the tree in a given BuildContext and when the dependencies of this widget change (e.g., an InheritedWidget referenced by this widget changes). This method can potentially be called in every frame and should not have any side effects beyond building a widget.

The framework replaces the subtree below this widget with the widget returned by this method, either by updating the existing subtree or by removing the subtree and inflating a new subtree, depending on whether the widget returned by this method can update the root of the existing subtree, as determined by calling Widget.canUpdate.

Typically implementations return a newly created constellation of widgets that are configured with information from this widget's constructor and from the given BuildContext.

The given BuildContext contains information about the location in the tree at which this widget is being built. For example, the context provides the set of inherited widgets for this location in the tree. A given widget might be built with multiple different BuildContext arguments over time if the widget is moved around the tree or if the widget is inserted into the tree in multiple places at once.

The implementation of this method must only depend on:

• the fields of the widget, which themselves must not change over time, and
• any ambient state obtained from the context using BuildContext.dependOnInheritedWidgetOfExactType.

If a widget's build method is to depend on anything else, use a StatefulWidget instead.

See also:

• StatelessWidget, which contains the discussion on performance considerations.

Implementation

@override
Widget build(BuildContext context) {
  // Resolve settings: start with base defaults, apply theme partial override
  // (only non-null fields), then let explicit widget settings win entirely.
  final themeData = GlassThemeData.of(context);
  const baseSettings = LiquidGlassSettings();
  final themeOverride = themeData.settingsFor(context);
  final withTheme = themeOverride?.applyTo(baseSettings) ?? baseSettings;
  final effectiveSettings = settings ?? withTheme;
  final effectiveQuality =
      quality ?? themeData.qualityFor(context) ?? GlassQuality.standard;

  // ---- MINIMAL FAST-PATH --------------------------------------------------
  // GlassQuality.minimal skips LiquidGlassLayer entirely.
  //
  // IMPORTANT: The layer has no shape — it wraps the full bounds including
  // any padding around pill/circle children. Painting a BackdropFilter +
  // tinted Container here bleeds into that padding area, creating the dark
  // rectangle visible above/around the individual glass shapes.
  //
  // The correct approach matches how LiquidGlassLayer works in the normal
  // path: the layer is a TRANSPARENT compositng context. Glass tinting and
  // blur come entirely from the child AdaptiveGlass widgets, each of which
  // renders as _FrostedFallback with correct shape-aware clipping.
  //
  // In minimal mode there are no blend groups, so the layer is a true
  // pass-through — just InheritedLiquidGlass so descendants can read
  // settings and quality.
  // -------------------------------------------------------------------------
  if (effectiveQuality == GlassQuality.minimal) {
    return InheritedLiquidGlass(
      settings: effectiveSettings,
      quality: effectiveQuality,
      isBlurProvidedByAncestor: false,
      child: child,
    );
  }

  // Detect if we should use the full Impeller-native rendering pipeline
  final bool useFullRenderer =
      _canUseImpeller && effectiveQuality == GlassQuality.premium;

  // On Skia/Web, we want to provide a single BackdropFilter for the whole layer
  // to avoid each child doing its own expensive blur.
  Widget content = child;

  return PremiumGlassTracker(
    child: LiquidGlassLayer(
      settings: effectiveSettings,
      child: InheritedLiquidGlass(
        settings: effectiveSettings,
        quality: effectiveQuality,
        isBlurProvidedByAncestor:
            false, // Root never provides the blur; containers do.
        child: useFullRenderer
            ? LiquidGlassBlendGroup(
                blend: blendAmount,
                child: content,
              )
            : content,
      ),
    ),
  );
}