QGraphicsAnchorLayout: move some private classes to a namespace with Q

Avoids polluting the global namespace

Change-Id: Ie01831ddac5446fdbdeefffd15468b5ca22d5e7b
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: David Faure <david.faure@kdab.com>

src/widgets/graphicsview/qgraphicsanchorlayout.h

@@ -70,7 +70,6 @@ private:
     Q_DECLARE_PRIVATE(QGraphicsAnchor)
 
     friend class QGraphicsAnchorLayoutPrivate;
-    friend struct AnchorData;
 };
 
 class Q_WIDGETS_EXPORT QGraphicsAnchorLayout : public QGraphicsLayout

src/widgets/graphicsview/qgraphicsanchorlayout_p.cpp

@@ -167,7 +167,7 @@ AnchorData::~AnchorData()
     if (graphicsAnchor) {
         // Remove reference to ourself to avoid double removal in
         // QGraphicsAnchorPrivate dtor.
-        graphicsAnchor->d_func()->data = 0;
+        QGraphicsAnchorPrivate::get(graphicsAnchor)->data = nullptr;
 
         delete graphicsAnchor;
     }
@@ -215,7 +215,7 @@ void AnchorData::refreshSizeHints(const QLayoutStyleInfo *styleInfo)
     } else {
         // It is a user-created anchor, fetch size information from the associated QGraphicsAnchor
         Q_ASSERT(graphicsAnchor);
-        QGraphicsAnchorPrivate *anchorPrivate = graphicsAnchor->d_func();
+        QGraphicsAnchorPrivate *anchorPrivate = QGraphicsAnchorPrivate::get(graphicsAnchor);
 
         // Policy, min and max sizes are straightforward
         policy = anchorPrivate->sizePolicy;

src/widgets/graphicsview/qgraphicsanchorlayout_p.h

@@ -73,6 +73,7 @@ QT_BEGIN_NAMESPACE
   respectively.
 */
 
+namespace QtGraphicsAnchorLayout {
 /*!
   \internal
 
@@ -326,6 +327,9 @@ public:
     QSet<AnchorData *> positives;
     QSet<AnchorData *> negatives;
 };
+} // namespace QtGraphicsAnchorLayout
+using namespace QtGraphicsAnchorLayout;
+
 Q_DECLARE_TYPEINFO(GraphPath, Q_MOVABLE_TYPE);
 
 class QGraphicsAnchorLayoutPrivate;
@@ -346,6 +350,9 @@ public:
 
     void setSizePolicy(QSizePolicy::Policy policy);
 
+    static QGraphicsAnchorPrivate *get(QGraphicsAnchor *q)
+    { return q->d_func(); }
+
     QGraphicsAnchorLayoutPrivate *layoutPrivate;
     AnchorData *data;