add dragable window

babylonia_terminal_launcher/lib/app.dart

@@ -110,7 +110,9 @@ class _MenuState extends State<Menu> {
 
     return ChangeNotifierProvider(
       create: (context) => Game(),
-      child: Scaffold(
+      child: Stack(
+        children: [
+          Scaffold(
             drawer: Drawer(
               child: ListView(
                 children: items,
@@ -166,6 +168,17 @@ class _MenuState extends State<Menu> {
             ),
             body: Screens.getCurrent(_selectedIndex),
           ),
+          Padding(
+            padding: const EdgeInsets.only(right: 115.0, left: 60.0),
+            child: GestureDetector(
+              onPanStart: (_) => window.drag(),
+              child: const SizedBox(
+                height: 60,
+              ),
+            ),
+          ),
+        ],
+      ),
     );
   }
 }