feat: import Chinese-localized Buzz source snapshot

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

mobile/lib/features/channels/compose_bar/dock.dart

@@ -0,0 +1,144 @@
+part of '../compose_bar.dart';
+
+class _ComposerDockFrame extends StatelessWidget {
+  final double widthFactor;
+  final Widget child;
+
+  const _ComposerDockFrame({required this.widthFactor, required this.child});
+
+  @override
+  Widget build(BuildContext context) {
+    final backdropHeight = mobileTabFooterBackdropHeight(context);
+    return Stack(
+      clipBehavior: Clip.none,
+      children: [
+        Positioned(
+          key: const ValueKey('composer-footer-gradient'),
+          left: 0,
+          right: 0,
+          bottom: 0,
+          height: backdropHeight,
+          child: IgnorePointer(
+            child: MobileTabFooterBackdrop(height: backdropHeight),
+          ),
+        ),
+        Padding(
+          padding: EdgeInsets.only(
+            left: Grid.twelve,
+            right: Grid.twelve,
+            bottom: MediaQuery.viewPaddingOf(context).bottom + Grid.xxs,
+          ),
+          child: Align(
+            alignment: Alignment.bottomCenter,
+            child: FractionallySizedBox(
+              key: const ValueKey('composer-width-transition'),
+              widthFactor: widthFactor,
+              child: child,
+            ),
+          ),
+        ),
+      ],
+    );
+  }
+}
+
+class _ComposerOverlayPortal extends StatelessWidget {
+  final OverlayPortalController controller;
+  final ValueListenable<_AttachmentSurface> attachmentSurface;
+  final bool reducedMotion;
+  final Widget Function(_AttachmentSurface surface) buildOverlayPanel;
+  final VoidCallback onDismissAttachmentSurface;
+  final Widget child;
+
+  const _ComposerOverlayPortal({
+    required this.controller,
+    required this.attachmentSurface,
+    required this.reducedMotion,
+    required this.buildOverlayPanel,
+    required this.onDismissAttachmentSurface,
+    required this.child,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    return OverlayPortal.overlayChildLayoutBuilder(
+      controller: controller,
+      overlayChildBuilder: (context, layoutInfo) {
+        final composerOrigin = MatrixUtils.transformPoint(
+          layoutInfo.childPaintTransform,
+          Offset.zero,
+        );
+        return ValueListenableBuilder<_AttachmentSurface>(
+          valueListenable: attachmentSurface,
+          builder: (context, surface, _) {
+            final surfaceDuration = reducedMotion
+                ? Duration.zero
+                : Duration(
+                    milliseconds:
+                        surface == _AttachmentSurface.camera ||
+                            surface == _AttachmentSurface.photos
+                        ? 320
+                        : 250,
+                  );
+            final expandedSurfaceCoversComposer =
+                surface == _AttachmentSurface.camera ||
+                surface == _AttachmentSurface.photos;
+            final surfaceLeft = expandedSurfaceCoversComposer
+                ? Grid.twelve
+                : composerOrigin.dx;
+            final surfaceWidth = expandedSurfaceCoversComposer
+                ? layoutInfo.overlaySize.width - (Grid.twelve * 2)
+                : layoutInfo.childSize.width;
+            final overlayAnchorY =
+                composerOrigin.dy +
+                (expandedSurfaceCoversComposer
+                    ? layoutInfo.childSize.height + Grid.twelve
+                    : 0);
+            return Stack(
+              children: [
+                if (surface != _AttachmentSurface.closed)
+                  Positioned(
+                    left: 0,
+                    top: 0,
+                    right: 0,
+                    height: composerOrigin.dy,
+                    child: ExcludeSemantics(
+                      child: GestureDetector(
+                        key: const ValueKey('attachment-dismiss-barrier'),
+                        behavior: HitTestBehavior.opaque,
+                        onTap: onDismissAttachmentSurface,
+                      ),
+                    ),
+                  ),
+                AnimatedPositioned(
+                  duration: surfaceDuration,
+                  curve:
+                      surface == _AttachmentSurface.camera ||
+                          surface == _AttachmentSurface.photos
+                      ? const Cubic(0.34, 1.25, 0.64, 1)
+                      : const Cubic(0.22, 1, 0.36, 1),
+                  left: surfaceLeft,
+                  bottom: layoutInfo.overlaySize.height - overlayAnchorY,
+                  width: surfaceWidth,
+                  child: ClipRect(
+                    child: Padding(
+                      padding: const EdgeInsets.only(bottom: Grid.xxs),
+                      child: surface == _AttachmentSurface.closed
+                          ? _SuggestionPanelMotion(
+                              duration: surfaceDuration,
+                              alignment: Alignment.bottomLeft,
+                              child: buildOverlayPanel(surface),
+                            )
+                          : buildOverlayPanel(surface),
+                    ),
+                  ),
+                ),
+              ],
+            );
+          },
+        );
+      },
+      child: child,
+    );
+  }
+}