flutter: add dockregistry tests

src/flutter/dart/test/models/dockregistry_test.dart

@@ -0,0 +1,48 @@
+/*
+  This file is part of KDDockWidgets.
+
+  SPDX-FileCopyrightText: 2024 Klarälvdalens Datakonsult AB, a KDAB Group company <[email protected]>
+  Author: Sérgio Martins <[email protected]>
+
+  SPDX-License-Identifier: GPL-2.0-only OR GPL-3.0-only
+
+  Contact KDAB at <[email protected]> for commercial licensing options.
+*/
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:KDDockWidgets/KDDockWidgets.dart';
+import 'package:KDDockWidgets/private/Bindings.dart';
+
+void main() {
+  test('Dockregistry', () {
+    final dr = DockRegistry.instance;
+    expect(dr.dockItems.isEmpty, true);
+    expect(dr.floatingItems.isEmpty, true);
+
+    final dock = DockItem(uniqueName: "dw1");
+
+    expect(dr.dockItems.length, 1);
+    expect(dr.floatingItems.isEmpty, true);
+
+    final fw = FloatingItem();
+    fw.dropArea.addDockItem(dock, Location.LocationOnTop);
+    expect(dr.dockItems.length, 1);
+    expect(dr.floatingItems.isEmpty, false);
+    expect(fw.dropArea.groups.length, 1);
+    expect(dr.dockItems.length, 1);
+    expect(dr.floatingItems.length, 1);
+
+    fw.dropArea.groups.first.titlebar.onCloseClicked();
+    expect(dr.dockItems.length, 1); // dock items are persistent
+    expect(dr.floatingItems.isEmpty, true); // discarded when empty
+    expect(fw.dropArea.groups.isEmpty, true);
+
+    final dock2 = DockItem(uniqueName: "dw2");
+
+    final fw2 = FloatingItem();
+    fw2.dropArea.addDockItem(dock2, Location.LocationOnTop);
+    expect(dr.floatingItems.length, 1);
+    fw2.dropArea.removeDockItem(fw2.dropArea.groups.first.currentDockItem!);
+    expect(dr.floatingItems.isEmpty, true);
+  });
+}