QmlDesigner: Add viewportTransform() to LayerItem

Change-Id: Ia90ae0a079922b3c1cdd429ee0f6e337c59267a5
Reviewed-by: Tim Jenssen <tim.jenssen@qt.io>

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

@@ -27,6 +27,9 @@
 
 #include <formeditorscene.h>
 
+#include <utils/qtcassert.h>
+
+#include <QGraphicsView>
 
 namespace QmlDesigner {
 
@@ -54,6 +57,14 @@ QList<QGraphicsItem*> LayerItem::findAllChildItems() const
     return findAllChildItems(this);
 }
 
+QTransform LayerItem::viewportTransform() const
+{
+    QTC_ASSERT(scene(), return {});
+    QTC_ASSERT(!scene()->views().isEmpty(), return {});
+
+    return scene()->views().first()->viewportTransform();
+}
+
 QList<QGraphicsItem*> LayerItem::findAllChildItems(const QGraphicsItem *item) const
 {
     QList<QGraphicsItem*> itemList(item->childItems());

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

@@ -25,6 +25,7 @@
 #pragma once
 
 #include <QGraphicsObject>
+#include <QTransform>
 
 namespace QmlDesigner {
 
@@ -45,6 +46,8 @@ public:
 
     QList<QGraphicsItem*> findAllChildItems() const;
 
+    QTransform viewportTransform() const;
+
 protected:
     QList<QGraphicsItem*> findAllChildItems(const QGraphicsItem *item) const;
 };