From 2836a2be1be91cd17fd1e525d47e0ec60d153657 Mon Sep 17 00:00:00 2001
From: Denis Dzyubenko <denis.dzyubenko@nokia.com>
Date: Mon, 18 May 2009 17:10:43 +0200
Subject: Moved gestures info to an extra in QGraphicsItemPrivate not to
 increase the size of the latter when gestures are not used

---
 src/gui/graphicsview/qgraphicsitem.cpp | 33 ++++++++++++++++++++-------------
 src/gui/graphicsview/qgraphicsitem_p.h | 30 ++++++++++++++++++++++++++++--
 2 files changed, 48 insertions(+), 15 deletions(-)

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index ae33674..fb95875 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -1055,6 +1055,7 @@ QGraphicsItem::~QGraphicsItem()
     clearFocus();
 
     d_ptr->removeExtraItemCache();
+    d_ptr->removeExtraGestures();
     QList<QGraphicsItem *> oldChildren = d_ptr->children;
     qDeleteAll(oldChildren);
     Q_ASSERT(d_ptr->children.isEmpty());
@@ -5880,7 +5881,7 @@ int QGraphicsItem::grabGesture(const QString &gesture)
 void QGraphicsItemPrivate::grabGesture(int id)
 {
     Q_Q(QGraphicsItem);
-    gestures << id;
+    extraGestures()->gestures << id;
     if (scene)
         scene->d_func()->grabGesture(q, id);
 }
@@ -5888,10 +5889,11 @@ void QGraphicsItemPrivate::grabGesture(int id)
 bool QGraphicsItemPrivate::releaseGesture(int id)
 {
     Q_Q(QGraphicsItem);
-    if (gestures.contains(id)) {
+    QGestureExtraData *extra = maybeExtraGestures();
+    if (extra && extra->gestures.contains(id)) {
         if (scene)
             scene->d_func()->releaseGesture(q, id);
-        gestures.remove(id);
+        extra->gestures.remove(id);
         return true;
     }
     return false;
@@ -5929,12 +5931,14 @@ void QGraphicsItem::setGestureEnabled(int gestureId, bool enable)
 
 bool QGraphicsItemPrivate::hasGesture(const QString &name) const
 {
-    QGestureManager *gm = QGestureManager::instance();
-    QSet<int>::const_iterator it = gestures.begin(),
-                               e = gestures.end();
-    for (; it != e; ++it) {
-        if (gm->gestureNameFromId(*it) == name)
-            return true;
+    if (QGestureExtraData *extra = maybeExtraGestures()) {
+        QGestureManager *gm = QGestureManager::instance();
+        QSet<int>::const_iterator it = extra->gestures.begin(),
+                                   e = extra->gestures.end();
+        for (; it != e; ++it) {
+            if (gm->gestureNameFromId(*it) == name)
+                return true;
+        }
     }
     return false;
 }
@@ -5964,16 +5968,19 @@ QVariant QGraphicsItem::itemChange(GraphicsItemChange change, const QVariant &va
 {
     Q_UNUSED(change);
     if (change == QGraphicsItem::ItemSceneChange) {
-        if (!qVariantValue<QGraphicsScene*>(value)) {
+        QGestureExtraData *extra = d_ptr->maybeExtraGestures();
+        if (!qVariantValue<QGraphicsScene*>(value) && extra) {
             // the item has been removed from a scene, unsubscribe gestures.
             Q_ASSERT(d_ptr->scene);
-            foreach(int id, d_ptr->gestures)
+            foreach(int id, extra->gestures)
                 d_ptr->scene->d_func()->releaseGesture(this, id);
         }
     } else if (change == QGraphicsItem::ItemSceneHasChanged) {
-        if (QGraphicsScene *scene = qVariantValue<QGraphicsScene*>(value)) {
+        QGraphicsScene *scene = qVariantValue<QGraphicsScene*>(value);
+        QGestureExtraData *extra = d_ptr->maybeExtraGestures();
+        if (scene && extra) {
             // item has been added to the scene
-            foreach(int id, d_ptr->gestures)
+            foreach(int id, extra->gestures)
                 scene->d_func()->grabGesture(this, id);
         }
     }
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 091a461..7642b98 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -90,6 +90,12 @@ public:
     void purge();
 };
 
+class QGestureExtraData
+{
+public:
+    QSet<int> gestures;
+};
+
 class Q_AUTOTEST_EXPORT QGraphicsItemPrivate
 {
     Q_DECLARE_PUBLIC(QGraphicsItem)
@@ -102,7 +108,8 @@ public:
         ExtraMaxDeviceCoordCacheSize,
         ExtraBoundingRegionGranularity,
         ExtraOpacity,
-        ExtraEffectiveOpacity
+        ExtraEffectiveOpacity,
+        ExtraGestures
     };
 
     enum AncestorFlag {
@@ -303,8 +310,27 @@ public:
     int siblingIndex;
     int index;
     int depth;
-    QSet<int> gestures;
 
+    inline QGestureExtraData* extraGestures() const
+    {
+        QGestureExtraData *c = (QGestureExtraData *)qVariantValue<void *>(extra(ExtraGestures));
+        if (!c) {
+            QGraphicsItemPrivate *that = const_cast<QGraphicsItemPrivate *>(this);
+            c = new QGestureExtraData;
+            that->setExtra(ExtraGestures, qVariantFromValue<void *>(c));
+        }
+        return c;
+    }
+    QGestureExtraData* maybeExtraGestures() const
+    {
+        return (QGestureExtraData *)qVariantValue<void *>(extra(ExtraGestures));
+    }
+    inline void removeExtraGestures()
+    {
+        QGestureExtraData *c = (QGestureExtraData *)qVariantValue<void *>(extra(ExtraGestures));
+        delete c;
+        unsetExtra(ExtraGestures);
+    }
     bool hasGesture(const QString &gesture) const;
     void grabGesture(int id);
     bool releaseGesture(int id);
-- 
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