#79 fix Allow custom the double tap process for MoveWindow. (#80)

* #79 fix Allow custom the double tap process for MoveWindow.

* Fixed to work when no child specified

Co-authored-by: Bits Dojo <bitsdojo@gmail.com>

Author: wcb33

bitsdojo_window/lib/src/widgets/window_caption.dart

@@ -3,27 +3,30 @@ import '../app_window.dart';
 import 'package:flutter/foundation.dart' show kIsWeb;
 
 class _MoveWindow extends StatelessWidget {
-  _MoveWindow({Key? key, this.child}) : super(key: key);
+  _MoveWindow({Key? key, this.child, this.onDoubleTap}) : super(key: key);
   final Widget? child;
+  final VoidCallback? onDoubleTap;
   @override
   Widget build(BuildContext context) {
     return GestureDetector(
         behavior: HitTestBehavior.translucent,
         onPanStart: (details) {
           appWindow.startDragging();
         },
-        onDoubleTap: () => appWindow.maximizeOrRestore(),
+        onDoubleTap: this.onDoubleTap ?? () => appWindow.maximizeOrRestore(),
         child: this.child ?? Container());
   }
 }
 
 class MoveWindow extends StatelessWidget {
   final Widget? child;
-  MoveWindow({Key? key, this.child}) : super(key: key);
+  final VoidCallback? onDoubleTap;
+  MoveWindow({Key? key, this.child, this.onDoubleTap}) : super(key: key);
   @override
   Widget build(BuildContext context) {
-    if (child == null) return _MoveWindow();
+    if (child == null) return _MoveWindow(onDoubleTap: this.onDoubleTap);
     return _MoveWindow(
+      onDoubleTap: this.onDoubleTap,
       child: Column(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [Expanded(child: this.child!)]),