QmlDesigner: Add Duplicate to 3d Context Menu

Duplicate action is added to the context menu of the Edit3DWidget.

Task-number: QDS-8063
Change-Id: Id1347d28cd819a81e145bb0319e85d19a734090f
Reviewed-by: Samuel Ghinet <samuel.ghinet@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>

src/plugins/qmldesigner/components/edit3d/edit3dwidget.cpp

@@ -183,6 +183,10 @@ void Edit3DWidget::createContextMenu()
 
     m_contextMenu->addSeparator();
 
+    m_duplicateAction = m_contextMenu->addAction(tr("Duplicate"), [&] {
+        QmlDesignerPlugin::instance()->currentDesignDocument()->duplicateSelected();
+    });
+
     m_copyAction = m_contextMenu->addAction(tr("Copy"), [&] {
         QmlDesignerPlugin::instance()->currentDesignDocument()->copySelected();
     });
@@ -374,6 +378,7 @@ void Edit3DWidget::showContextMenu(const QPoint &pos, const ModelNode &modelNode
 
     m_editComponentAction->setEnabled(isSingleComponent);
     m_editMaterialAction->setEnabled(isModel);
+    m_duplicateAction->setEnabled(isNotRoot);
     m_copyAction->setEnabled(isNotRoot);
     m_pasteAction->setEnabled(isPasteAvailable());
     m_deleteAction->setEnabled(isNotRoot);

src/plugins/qmldesigner/components/edit3d/edit3dwidget.h

@@ -64,6 +64,7 @@ private:
     QPointer<QMenu> m_contextMenu;
     QPointer<QAction> m_editComponentAction;
     QPointer<QAction> m_editMaterialAction;
+    QPointer<QAction> m_duplicateAction;
     QPointer<QAction> m_copyAction;
     QPointer<QAction> m_pasteAction;
     QPointer<QAction> m_deleteAction;

src/plugins/qmldesigner/components/integration/designdocument.cpp

@@ -579,6 +579,18 @@ void DesignDocument::cutSelected()
     deleteSelected();
 }
 
+void DesignDocument::duplicateSelected()
+{
+    DesignDocumentView view{m_externalDependencies};
+    currentModel()->attachView(&view);
+    const QList<ModelNode> selectedNodes = view.selectedModelNodes();
+    currentModel()->detachView(&view);
+
+    rewriterView()->executeInTransaction("DesignDocument::duplicateSelected", [this, selectedNodes]() {
+        moveNodesToPosition(selectedNodes, {});
+    });
+}
+
 void DesignDocument::paste()
 {
     pasteToPosition({});

src/plugins/qmldesigner/components/integration/designdocument.h

@@ -98,6 +98,7 @@ public:
     void deleteSelected();
     void copySelected();
     void cutSelected();
+    void duplicateSelected();
     void paste();
     void pasteToPosition(const std::optional<QVector3D> &position);
     void selectAll();