QmlDesigner: The items of the form editor should not accept buttons

The mouse buttons are handled by the tools.

Change-Id: Ie47818e7acfe32db69d9258175580c7cdb05ed5e
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

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

@@ -60,6 +60,7 @@ FormEditorItem::FormEditorItem(const QmlItemNode &qmlItemNode, FormEditorScene*
 
 void FormEditorItem::setup()
 {
+    setAcceptedMouseButtons(Qt::NoButton);
     if (qmlItemNode().hasInstanceParent()) {
         setParentItem(scene()->itemForQmlItemNode(qmlItemNode().instanceParent().toQmlItemNode()));
         setOpacity(qmlItemNode().instanceValue("opacity").toDouble());

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

@@ -36,6 +36,7 @@ LayerItem::LayerItem(FormEditorScene* scene)
     scene->addItem(this);
     setZValue(1);
     setFlag(QGraphicsItem::ItemIsMovable, false);
+    setAcceptedMouseButtons(Qt::NoButton);
 }
 
 LayerItem::~LayerItem()

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

@@ -35,6 +35,7 @@ ResizeHandleItem::ResizeHandleItem(QGraphicsItem *parent, const ResizeController
 {
     setFlag(QGraphicsItem::ItemIsMovable, true);
     setFlag(QGraphicsItem::ItemIgnoresTransformations, true);
+    setAcceptedMouseButtons(Qt::NoButton);
 }
 
 ResizeHandleItem::~ResizeHandleItem()