Override virtual method in private class instead of downcasting

Move QGraphicsView specific code into reimplementation of now virtual
(and const) canStartScrollingAt.

Remove unhelpful comment.

Change-Id: Ib4799e48ac4f85748c77c52d29511a0490303676
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

2 files changed, 21 insertions, 0 deletions

diff --git a/src/widgets/graphicsview/qgraphicsview.cpp b/src/widgets/graphicsview/qgraphicsview.cpp
index 338d553108..37141c4166 100644
--- a/src/widgets/graphicsview/qgraphicsview.cpp
+++ b/src/widgets/graphicsview/qgraphicsview.cpp
@@ -615,6 +615,26 @@ void QGraphicsViewPrivate::updateScroll()
 
 /*!
     \internal
+
+    * don't start scrolling when a drag mode has been set
+    * don't start scrolling on a movable item
+*/
+bool QGraphicsViewPrivate::canStartScrollingAt(const QPoint &startPos) const
+{
+    Q_Q(const QGraphicsView);
+    if (q->dragMode() != QGraphicsView::NoDrag)
+        return false;
+
+    const QGraphicsItem *childItem = q->itemAt(startPos);
+
+    if (childItem && (childItem->flags() & QGraphicsItem::ItemIsMovable))
+        return false;
+
+    return QAbstractScrollAreaPrivate::canStartScrollingAt(startPos);
+}
+
+/*!
+    \internal
 */
 void QGraphicsViewPrivate::replayLastMouseEvent()
 {
diff --git a/src/widgets/graphicsview/qgraphicsview_p.h b/src/widgets/graphicsview/qgraphicsview_p.h
index e877e6e887..b58505b057 100644
--- a/src/widgets/graphicsview/qgraphicsview_p.h
+++ b/src/widgets/graphicsview/qgraphicsview_p.h
@@ -117,6 +117,7 @@ public:
     QTransform matrix;
     qint64 scrollX, scrollY;
     void updateScroll();
+    bool canStartScrollingAt(const QPoint &startPos) const override;
 
     qreal leftIndent;
     qreal topIndent;