mod: show all the staffs on intro panel

lib/common/widgets/self_sized_horizontal_list.dart

@@ -0,0 +1,67 @@
+import 'package:flutter/material.dart';
+
+/// https://stackoverflow.com/a/76605401
+
+class SelfSizedHorizontalList extends StatefulWidget {
+  final Widget Function(int) childBuilder;
+  final int itemCount;
+  final double gapSize;
+  final EdgeInsetsGeometry? padding;
+  const SelfSizedHorizontalList({
+    super.key,
+    required this.childBuilder,
+    required this.itemCount,
+    this.gapSize = 5,
+    this.padding,
+  });
+
+  @override
+  State<SelfSizedHorizontalList> createState() =>
+      _SelfSizedHorizontalListState();
+}
+
+class _SelfSizedHorizontalListState extends State<SelfSizedHorizontalList> {
+  final infoKey = GlobalKey();
+
+  double? prevHeight;
+  double? get height {
+    if (prevHeight != null) return prevHeight;
+    prevHeight = infoKey.globalPaintBounds?.height;
+    return prevHeight;
+  }
+
+  bool get isInit => height == null;
+
+  @override
+  Widget build(BuildContext context) {
+    if (height == null) {
+      WidgetsBinding.instance.addPostFrameCallback((v) => setState(() {}));
+    }
+    if (widget.itemCount == 0) return const SizedBox();
+    if (isInit) return Container(key: infoKey, child: widget.childBuilder(0));
+
+    return SizedBox(
+      height: height,
+      child: ListView.separated(
+        padding: widget.padding,
+        scrollDirection: Axis.horizontal,
+        itemCount: widget.itemCount,
+        itemBuilder: (c, i) => widget.childBuilder.call(i),
+        separatorBuilder: (c, i) => SizedBox(width: widget.gapSize),
+      ),
+    );
+  }
+}
+
+extension GlobalKeyExtension on GlobalKey {
+  Rect? get globalPaintBounds {
+    final renderObject = currentContext?.findRenderObject();
+    final translation = renderObject?.getTransformTo(null).getTranslation();
+    if (translation != null && renderObject?.paintBounds != null) {
+      final offset = Offset(translation.x, translation.y);
+      return renderObject!.paintBounds.shift(offset);
+    } else {
+      return null;
+    }
+  }
+}