QmlDesigner: Fix issues with Components and Repeaters

- Fixed state preview rendering by deparenting nodes under
  component wraps.
- Ensure state preview image is always clipped to root item.
  The state preview bounding box broke when Repeater was direct
  child of root and had delegate with rotation.
- Allow dragging items under Repeater to create implicit component.
- Allow dragging Components under Repeater.
- Do not ask for target property when Component is dragged under
  any node.
- Update nodeSource properly when reparenting implicit component
  or removing last child of a Component item.
- Fixed scene update when last child of a repeater is deleted/moved.

Fixes: QDS-5197
Change-Id: Iaaf1745e25db3522ffc1dba7fd1b051da29f5aec
Reviewed-by: Samuel Ghinet <samuel.ghinet@qt.io>
Reviewed-by: Mahmoud Badri <mahmoud.badri@qt.io>
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/nodeinstanceserver.cpp

@@ -397,8 +397,19 @@ void NodeInstanceServer::reparentInstances(const QVector<ReparentContainer> &con
         if (hasInstanceForId(container.instanceId())) {
             ServerNodeInstance instance = instanceForId(container.instanceId());
             if (instance.isValid()) {
-                instance.reparent(instanceForId(container.oldParentInstanceId()), container.oldParentProperty(),
-                                  instanceForId(container.newParentInstanceId()), container.newParentProperty());
+                ServerNodeInstance newParent = instanceForId(container.newParentInstanceId());
+                PropertyName newParentProperty = container.newParentProperty();
+                if (!isInformationServer()) {
+                    // Children of the component wraps are left out of the node tree to avoid
+                    // incorrectly rendering them
+                    if (newParent.isComponentWrap()) {
+                        newParent = {};
+                        newParentProperty.clear();
+                    }
+                }
+                instance.reparent(instanceForId(container.oldParentInstanceId()),
+                                  container.oldParentProperty(),
+                                  newParent, newParentProperty);
             }
         }
     }

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.cpp

@@ -415,6 +415,16 @@ bool ObjectNodeInstance::isLockedInEditor() const
     return m_isLockedInEditor;
 }
 
+bool ObjectNodeInstance::isComponentWrap() const
+{
+    return m_isComponentWrap;
+}
+
+void ObjectNodeInstance::setComponentWrap(bool wrap)
+{
+    m_isComponentWrap = wrap;
+}
+
 void ObjectNodeInstance::setModifiedFlag(bool b)
 {
     m_isModified = b;
@@ -732,6 +742,10 @@ QObject *ObjectNodeInstance::createComponentWrap(const QString &nodeSource, cons
     QQmlComponent *component = new QQmlComponent(context->engine());
 
     QByteArray data(nodeSource.toUtf8());
+    if (data.isEmpty()) {
+        // Add a fake root element as an empty component is not valid and crashes in some cases
+        data.append("QtObject{}");
+    }
     data.prepend(importCode);
     component->setData(data, context->baseUrl().resolved(QUrl("createComponent.qml")));
     QObject *object = component;

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/objectnodeinstance.h

@@ -202,6 +202,9 @@ public:
     virtual void setLockedInEditor(bool b);
     bool isLockedInEditor() const;
 
+    bool isComponentWrap() const;
+    void setComponentWrap(bool wrap);
+
     void setModifiedFlag(bool b);
 
 protected:
@@ -234,6 +237,7 @@ private:
     bool m_isModified = false;
     bool m_isLockedInEditor = false;
     bool m_isHiddenInEditor = false;
+    bool m_isComponentWrap = false;
     static QHash<EnumerationName, QVariant> m_enumationValueHash;
 };
 

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5nodeinstanceserver.cpp

@@ -199,11 +199,24 @@ void Qt5NodeInstanceServer::markRepeaterParentDirty(qint32 id) const
     if (!hasInstanceForId(id))
         return;
 
-    // If a Repeater instance was moved/removed, the old parent must be marked dirty to rerender it
     ServerNodeInstance instance = instanceForId(id);
-    if (instance.isValid() && instance.isSubclassOf("QQuickRepeater") && instance.hasParent()) {
-        ServerNodeInstance parentInstance = instance.parent();
+    if (!instance.isValid())
+        return;
+
+    ServerNodeInstance parentInstance = instance.parent();
+    if (!parentInstance.isValid())
+        return;
+
+    // If a Repeater instance was moved/removed, the old parent must be marked dirty to rerender it
+    const QByteArray type("QQuickRepeater");
+    if (ServerNodeInstance::isSubclassOf(instance.internalObject(), type))
         DesignerSupport::addDirty(parentInstance.rootQuickItem(), QQuickDesignerSupport::Content);
+
+    // Repeater's parent must also be dirtied when a child of a repeater was moved/removed.
+    if (ServerNodeInstance::isSubclassOf(parentInstance.internalObject(), type)) {
+        ServerNodeInstance parentsParent = parentInstance.parent();
+        if (parentsParent.isValid())
+            DesignerSupport::addDirty(parentsParent.rootQuickItem(), QQuickDesignerSupport::Content);
     }
 }
 

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/qt5previewnodeinstanceserver.cpp

@@ -101,6 +101,10 @@ void Qt5PreviewNodeInstanceServer::changeState(const ChangeStateCommand &/*comma
 
 QImage Qt5PreviewNodeInstanceServer::renderPreviewImage()
 {
+    // Ensure the state preview image is always clipped properly to root item dimensions
+    if (auto rootItem = qobject_cast<QQuickItem *>(rootNodeInstance().internalObject()))
+        rootItem->setClip(true);
+
     rootNodeInstance().updateDirtyNodeRecursive();
 
     QRectF boundingRect = rootNodeInstance().boundingRect();

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/quickitemnodeinstance.cpp

@@ -769,6 +769,9 @@ void QuickItemNodeInstance::reparent(const ObjectNodeInstance::Pointer &oldParen
 
     ObjectNodeInstance::reparent(oldParentInstance, oldParentProperty, newParentInstance, newParentProperty);
 
+    if (!newParentInstance)
+        quickItem()->setParentItem(nullptr);
+
     if (instanceIsValidLayoutable(newParentInstance, newParentProperty)) {
         setInLayoutable(true);
         setMovable(false);

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/servernodeinstance.cpp

@@ -150,6 +150,11 @@ bool ServerNodeInstance::holdsGraphical() const
     return m_nodeInstance->isQuickItem();
 }
 
+bool ServerNodeInstance::isComponentWrap() const
+{
+    return m_nodeInstance->isComponentWrap();
+}
+
 void ServerNodeInstance::updateDirtyNodeRecursive()
 {
     m_nodeInstance->updateAllDirtyNodesRecursive();
@@ -280,6 +285,8 @@ ServerNodeInstance ServerNodeInstance::create(NodeInstanceServer *nodeInstanceSe
 
     instance.internalInstance()->setInstanceId(instanceContainer.instanceId());
 
+    instance.internalInstance()->setComponentWrap(componentWrap == WrapAsComponent);
+
     instance.internalInstance()->initialize(instance.m_nodeInstance, instanceContainer.metaFlags());
 
     // Handle hidden state to initialize pickable state

share/qtcreator/qml/qmlpuppet/qml2puppet/instances/servernodeinstance.h

@@ -178,6 +178,8 @@ public:
     void updateDirtyNodeRecursive();
     bool holdsGraphical() const;
 
+    bool isComponentWrap() const;
+
 private: // functions
     ServerNodeInstance(const QSharedPointer<Internal::ObjectNodeInstance> &abstractInstance);