Fixed crash on deleting an item while resize tool is being hovered

Task-number: BAUHAUS-425
Reviewed-by: marco

src/plugins/qmldesigner/components/formeditor/resizecontroller.cpp

@@ -221,7 +221,7 @@ void ResizeController::updatePosition()
 
 FormEditorItem* ResizeController::formEditorItem() const
 {
-    return m_data->formEditorItem;
+    return m_data->formEditorItem.data();
 }
 
 QWeakPointer<ResizeControllerData> ResizeController::weakPointer() const

src/plugins/qmldesigner/components/formeditor/resizecontroller.h

@@ -51,7 +51,7 @@ public:
 
 
     QWeakPointer<LayerItem> layerItem;
-    FormEditorItem *formEditorItem;
+    QWeakPointer<FormEditorItem> formEditorItem;
     ResizeHandleItem *topLeftItem;
     ResizeHandleItem *topRightItem;
     ResizeHandleItem *bottomLeftItem;

src/plugins/qmldesigner/components/formeditor/resizetool.cpp

@@ -62,7 +62,7 @@ void ResizeTool::mousePressEvent(const QList<QGraphicsItem*> &itemList,
         return;
 
     ResizeHandleItem *resizeHandle = ResizeHandleItem::fromGraphicsItem(itemList.first());
-    if (resizeHandle) {
+    if (resizeHandle && resizeHandle->resizeController().isValid()) {
         m_resizeManipulator.setHandle(resizeHandle);
         m_resizeManipulator.begin(event->scenePos());
         m_resizeIndicator.hide();
@@ -92,7 +92,7 @@ void ResizeTool::hoverMoveEvent(const QList<QGraphicsItem*> &itemList,
     if (itemList.isEmpty())
         return;
     ResizeHandleItem* resizeHandle = ResizeHandleItem::fromGraphicsItem(itemList.first());
-    if (resizeHandle) {
+    if (resizeHandle && resizeHandle->resizeController().isValid()) {
         m_resizeManipulator.setHandle(resizeHandle);
     } else {
         view()->changeToSelectionTool();