flutter: Reuse more code, move code into View_mixin

src/flutter/dart/lib/DockWidget_flutter.dart

@@ -21,13 +21,8 @@ class DockWidget_flutter extends KDDockWidgetBindings.DockWidget_flutter
       {int options = 0, int layoutSaverOptions = 0})
       : super(uniqueName,
             options: options, layoutSaverOptions: layoutSaverOptions) {
-    m_color = Colors.pink;
+    initMixin(this, color: Colors.pink, debugName: "DockWidget");
     m_fillsParent = true;
-    kddwView = this;
-    final ffi.Pointer<ffi.Void> ptr = thisCpp.cast<ffi.Void>();
-    widgetKey = GlobalObjectKey(ptr.address);
-    flutterWidget = PositionedWidget(this, key: widgetKey);
-    debugName = "DockWidget";
     print("DockWidget_flutter CTOR");
   }
 }

src/flutter/dart/lib/Group_flutter.dart

@@ -19,12 +19,8 @@ class Group_flutter extends KDDockWidgetBindings.Group_flutter with View_mixin {
   Group_flutter(
       KDDockWidgetBindings.Group? group, KDDockWidgetBindings.View? parent)
       : super(group, parent: parent) {
-    m_color = Colors.greenAccent;
-    kddwView = this;
-    final ffi.Pointer<ffi.Void> ptr = thisCpp.cast<ffi.Void>();
-    widgetKey = GlobalObjectKey(ptr.address);
-    flutterWidget = PositionedWidget(this, key: widgetKey);
-    debugName = "group";
+    initMixin(this, color: Colors.greenAccent, debugName: "Group");
+
     print("Group_flutter CTOR");
   }
 }

src/flutter/dart/lib/View_flutter.dart

@@ -20,23 +20,11 @@ class View_flutter extends KDDockWidgetBindings.View_flutter with View_mixin {
       KDDockWidgetBindings.View? parent,
       {int windowFlags = 0})
       : super(controller, type, parent, windowFlags: windowFlags) {
-    initMixin();
+    initMixin(this);
   }
 
   View_flutter.fromCppPointer(var cppPointer, [var needsAutoDelete = false])
       : super.fromCppPointer(cppPointer, needsAutoDelete) {
-    initMixin();
-  }
-
-  void initMixin() {
-    // The key is the C++ KDDockWidget pointer, which is stable and unique
-    final ffi.Pointer<ffi.Void> ptr = thisCpp.cast<ffi.Void>();
-    widgetKey = GlobalObjectKey(ptr.address);
-    kddwView = this;
-    flutterWidget = createFlutterWidget();
-  }
-
-  Widget createFlutterWidget() {
-    return PositionedWidget(this, key: widgetKey);
+    initMixin(this);
   }
 }

src/flutter/dart/lib/View_mixin.dart

@@ -9,14 +9,11 @@
   Contact KDAB at <info@kdab.com> for commercial licensing options.
 */
 
+import 'dart:ffi' as ffi;
 import 'package:KDDockWidgets/PositionedWidget.dart';
 import 'package:KDDockWidgetsBindings/Bindings.dart' as KDDockWidgetBindings;
-import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
-import 'Group_flutter.dart';
-import 'View_flutter.dart';
-
 class View_mixin {
   late final Widget flutterWidget;
   late final GlobalObjectKey<PositionedWidgetState> widgetKey;
@@ -35,6 +32,18 @@ class View_mixin {
 
   var childWidgets = <Widget>[];
 
+  void initMixin(var kddwView, {var color = Colors.red, var debugName = ""}) {
+    this.kddwView = kddwView;
+    m_color = color;
+    this.debugName = debugName;
+
+    // The key is the C++ View pointer, which is stable and unique
+    final ffi.Pointer<ffi.Void> ptr = kddwView.thisCpp.cast<ffi.Void>();
+    widgetKey = GlobalObjectKey(ptr.address);
+
+    flutterWidget = createFlutterWidget();
+  }
+
   setSize_2(int width, int height) {
     // print(
     //     "View_mixin::setSize called ${width}x${height} ; old=${m_width}x${height}");
@@ -128,4 +137,8 @@ class View_mixin {
       }
     }
   }
+
+  Widget createFlutterWidget() {
+    return PositionedWidget(this, key: widgetKey);
+  }
 }