feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

mobile/lib/shared/widgets/anchored_popover_menu.dart

@@ -0,0 +1,272 @@
+import 'dart:math' as math;
+import 'dart:ui' show SemanticsRole;
+
+import 'package:flutter/material.dart';
+
+import '../theme/theme.dart';
+
+const _popoverEnterDuration = Duration(milliseconds: 150);
+const _popoverExitDuration = Duration(milliseconds: 110);
+const _popoverStartScale = 0.96;
+
+/// Elevation shared by anchored menus and composer popover surfaces.
+const appPopoverElevation = 8.0;
+
+/// Returns the translucent surface color shared by app popovers.
+Color appPopoverColor(BuildContext context) =>
+    context.colors.surface.withValues(alpha: 0.98);
+
+/// Returns the shadow color shared by app popovers.
+Color appPopoverShadowColor(BuildContext context) =>
+    context.colors.shadow.withValues(alpha: 0.18);
+
+/// Returns the 20px shape and composer-matching hairline shared by popovers.
+RoundedRectangleBorder appPopoverShape(BuildContext context) =>
+    RoundedRectangleBorder(
+      borderRadius: BorderRadius.circular(Radii.popover),
+      side: BorderSide(color: Colors.black.withValues(alpha: 0.04), width: 1),
+    );
+
+/// The horizontal edge a popover aligns to on its triggering control.
+enum AnchoredPopoverAlignment {
+  /// Aligns the popover's leading edge with the trigger's leading edge.
+  start,
+
+  /// Centers the popover horizontally on the trigger.
+  center,
+
+  /// Aligns the popover's trailing edge with the trigger's trailing edge.
+  end,
+}
+
+/// Shows an anchored, cross-platform popup menu with the Activity controls'
+/// sizing, motion, and safe-area placement.
+Future<T?> showAnchoredPopover<T>({
+  required BuildContext context,
+  required List<PopupMenuEntry<T>> items,
+  required double width,
+  required AnchoredPopoverAlignment alignment,
+  Color? color,
+  ShapeBorder? shape,
+  double elevation = appPopoverElevation,
+  Color? shadowColor,
+  Offset offset = Offset.zero,
+  EdgeInsetsGeometry menuPadding = EdgeInsets.zero,
+  Clip clipBehavior = Clip.antiAlias,
+  Key? surfaceKey,
+}) {
+  final navigator = Navigator.of(context);
+  final overlay = navigator.overlay;
+  final triggerRenderObject = context.findRenderObject();
+  final overlayRenderObject = overlay?.context.findRenderObject();
+  if (triggerRenderObject is! RenderBox || overlayRenderObject is! RenderBox) {
+    return Future<T?>.value();
+  }
+
+  final triggerRect = MatrixUtils.transformRect(
+    triggerRenderObject.getTransformTo(overlayRenderObject),
+    Offset.zero & triggerRenderObject.size,
+  );
+  final overlayRect = Offset.zero & overlayRenderObject.size;
+  final mediaQuery = MediaQuery.of(context);
+
+  return navigator.push<T>(
+    _AnchoredPopoverRoute<T>(
+      position: RelativeRect.fromRect(triggerRect, overlayRect),
+      items: items,
+      width: width,
+      alignment: alignment,
+      offset: offset,
+      color: color ?? appPopoverColor(context),
+      shape: shape ?? appPopoverShape(context),
+      elevation: elevation,
+      shadowColor: shadowColor ?? appPopoverShadowColor(context),
+      menuPadding: menuPadding,
+      clipBehavior: clipBehavior,
+      surfaceKey: surfaceKey,
+      screenPadding: EdgeInsets.fromLTRB(
+        math.max(Grid.xxs, mediaQuery.padding.left),
+        math.max(Grid.xxs, mediaQuery.padding.top),
+        math.max(Grid.xxs, mediaQuery.padding.right),
+        math.max(Grid.xxs, mediaQuery.padding.bottom),
+      ),
+      reducedMotion: mediaQuery.disableAnimations,
+      barrierLabel: MaterialLocalizations.of(context).modalBarrierDismissLabel,
+    ),
+  );
+}
+
+class _AnchoredPopoverRoute<T> extends PopupRoute<T> {
+  final RelativeRect position;
+  final List<PopupMenuEntry<T>> items;
+  final double width;
+  final AnchoredPopoverAlignment alignment;
+  final Offset offset;
+  final Color color;
+  final ShapeBorder shape;
+  final double elevation;
+  final Color shadowColor;
+  final EdgeInsetsGeometry menuPadding;
+  final Clip clipBehavior;
+  final Key? surfaceKey;
+  final EdgeInsets screenPadding;
+  final bool reducedMotion;
+  final String _barrierLabel;
+
+  _AnchoredPopoverRoute({
+    required this.position,
+    required this.items,
+    required this.width,
+    required this.alignment,
+    required this.offset,
+    required this.color,
+    required this.shape,
+    required this.elevation,
+    required this.shadowColor,
+    required this.menuPadding,
+    required this.clipBehavior,
+    required this.surfaceKey,
+    required this.screenPadding,
+    required this.reducedMotion,
+    required String barrierLabel,
+  }) : _barrierLabel = barrierLabel;
+
+  @override
+  Color? get barrierColor => null;
+
+  @override
+  bool get barrierDismissible => true;
+
+  @override
+  String? get barrierLabel => _barrierLabel;
+
+  @override
+  Duration get transitionDuration =>
+      reducedMotion ? Duration.zero : _popoverEnterDuration;
+
+  @override
+  Duration get reverseTransitionDuration =>
+      reducedMotion ? Duration.zero : _popoverExitDuration;
+
+  @override
+  Widget buildPage(
+    BuildContext context,
+    Animation<double> animation,
+    Animation<double> secondaryAnimation,
+  ) {
+    final curvedAnimation = animation.drive(
+      CurveTween(curve: Curves.easeOutCubic),
+    );
+    final scaleAnimation = Tween<double>(
+      begin: _popoverStartScale,
+      end: 1,
+    ).animate(curvedAnimation);
+    final transformOrigin = switch (alignment) {
+      AnchoredPopoverAlignment.start => Alignment.topLeft,
+      AnchoredPopoverAlignment.center => Alignment.topCenter,
+      AnchoredPopoverAlignment.end => Alignment.topRight,
+    };
+
+    return CustomSingleChildLayout(
+      delegate: _AnchoredPopoverLayoutDelegate(
+        position: position,
+        alignment: alignment,
+        offset: offset,
+        screenPadding: screenPadding,
+      ),
+      child: FadeTransition(
+        key: const ValueKey('activity-popover-fade'),
+        opacity: curvedAnimation,
+        child: ScaleTransition(
+          key: const ValueKey('activity-popover-scale'),
+          scale: scaleAnimation,
+          alignment: transformOrigin,
+          child: Material(
+            key: surfaceKey,
+            type: MaterialType.card,
+            color: color,
+            surfaceTintColor: Colors.transparent,
+            elevation: elevation,
+            shadowColor: shadowColor,
+            shape: shape,
+            clipBehavior: clipBehavior,
+            child: SizedBox(
+              width: width,
+              child: Semantics(
+                role: SemanticsRole.menu,
+                scopesRoute: true,
+                namesRoute: true,
+                explicitChildNodes: true,
+                child: SingleChildScrollView(
+                  padding: menuPadding,
+                  child: ListBody(children: items),
+                ),
+              ),
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _AnchoredPopoverLayoutDelegate extends SingleChildLayoutDelegate {
+  final RelativeRect position;
+  final AnchoredPopoverAlignment alignment;
+  final Offset offset;
+  final EdgeInsets screenPadding;
+
+  const _AnchoredPopoverLayoutDelegate({
+    required this.position,
+    required this.alignment,
+    required this.offset,
+    required this.screenPadding,
+  });
+
+  @override
+  BoxConstraints getConstraintsForChild(BoxConstraints constraints) {
+    return BoxConstraints.loose(
+      Size(
+        constraints.maxWidth - screenPadding.horizontal,
+        constraints.maxHeight - screenPadding.vertical,
+      ),
+    );
+  }
+
+  @override
+  Offset getPositionForChild(Size size, Size childSize) {
+    final anchorBottom = size.height - position.bottom;
+    final desiredX = switch (alignment) {
+      AnchoredPopoverAlignment.start => position.left + offset.dx,
+      AnchoredPopoverAlignment.center =>
+        position.left +
+            (size.width - position.left - position.right - childSize.width) /
+                2 +
+            offset.dx,
+      AnchoredPopoverAlignment.end =>
+        size.width - position.right - childSize.width + offset.dx,
+    };
+    final minX = screenPadding.left;
+    final maxX = size.width - screenPadding.right - childSize.width;
+    final x = desiredX.clamp(minX, maxX).toDouble();
+
+    final belowY = anchorBottom + offset.dy;
+    final aboveY = position.top - childSize.height - offset.dy;
+    final maxY = size.height - screenPadding.bottom - childSize.height;
+    final desiredY =
+        belowY + childSize.height <= size.height - screenPadding.bottom
+        ? belowY
+        : aboveY;
+    final y = desiredY.clamp(screenPadding.top, maxY).toDouble();
+
+    return Offset(x, y);
+  }
+
+  @override
+  bool shouldRelayout(_AnchoredPopoverLayoutDelegate oldDelegate) {
+    return position != oldDelegate.position ||
+        alignment != oldDelegate.alignment ||
+        offset != oldDelegate.offset ||
+        screenPadding != oldDelegate.screenPadding;
+  }
+}