refactor

gui/lib/src/widget/snackbar/snackbar_area.dart

@@ -0,0 +1,53 @@
+import 'package:fluent_ui/fluent_ui.dart';
+import 'package:reboot_launcher/src/widget/sections.dart';
+
+class SnackBarArea extends StatefulWidget {
+  const SnackBarArea({super.key});
+
+  @override
+  State<SnackBarArea> createState() => SnackBarAreaState();
+}
+
+class SnackBarAreaState extends State<SnackBarArea> {
+  final List<Widget> _children = [];
+
+  void insertChild(Widget child) {
+    setState(() {
+      _children.add(child);
+    });
+  }
+
+  bool removeChild(Widget child) {
+    var result = false;
+    setState(() {
+      result = _children.remove(child);
+    });
+    return result;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return StreamBuilder(
+      stream: pagesController.stream,
+      builder: (context, _) => Padding(
+        padding: EdgeInsets.only(
+          bottom: hasPageButton ? 72.0 : 16.0,
+        ),
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.end,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: _snackbars,
+        ),
+      ),
+    );
+  }
+
+  List<Widget> get _snackbars => _children
+      .map((child) => _buildSnackbar(child))
+      .toList(growable: false);
+
+  Widget _buildSnackbar(Widget child) => Padding(
+    padding: const EdgeInsets.only(top: 12.0),
+    child: child,
+  );
+}