Fix a bug when clipsChildrenToShape is set back to false.

If you set the flag itemClipsChildrenToShape to true on a parent, an
optimization was made in 4.5.0 to not add children of this parent in
the index. But when you set the flag back to false all the sub-tree
of the parent should be re-added to the index otherwise the index will
never find all children. This code is not relevant for 4.6 since
the index part of QGraphicsView has been refactored and handle this case
with itemChange in QGraphicsSceneIndex.

Reviewed-by:andreas

4 files changed, 59 insertions, 0 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index 4f77aa8..280c365 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -1262,6 +1262,9 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
         d_ptr->updateAncestorFlag(ItemClipsChildrenToShape);
     }
 
+    if (d_ptr->scene && oldFlags & ItemClipsChildrenToShape)
+        d_ptr->scene->d_func()->addToUnindexedItems(this);
+
     if ((flags & ItemClipsToShape) != (oldFlags & ItemClipsToShape))
         d_ptr->invalidateCachedClipPath();
 
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index 0fded89..5c3e9bd 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -448,6 +448,20 @@ void QGraphicsScenePrivate::addToIndex(QGraphicsItem *item)
 /*!
     \internal
 */
+void QGraphicsScenePrivate::addToUnindexedItems(QGraphicsItem *item)
+{
+    if (indexMethod == QGraphicsScene::BspTreeIndex) {
+        item->d_func()->index = -1;
+        unindexedItems << item;
+
+        for (int i = 0 ; i < item->d_ptr->children.size() ; ++i)
+            addToUnindexedItems(item->d_ptr->children.at(i));
+    }
+}
+
+/*!
+    \internal
+*/
 void QGraphicsScenePrivate::removeFromIndex(QGraphicsItem *item)
 {
     if (indexMethod == QGraphicsScene::BspTreeIndex) {
diff --git a/src/gui/graphicsview/qgraphicsscene_p.h b/src/gui/graphicsview/qgraphicsscene_p.h
index 3c72874..62bcbfb 100644
--- a/src/gui/graphicsview/qgraphicsscene_p.h
+++ b/src/gui/graphicsview/qgraphicsscene_p.h
@@ -89,6 +89,7 @@ public:
     QList<QGraphicsItem *> estimateItemsInRect(const QRectF &rect) const;
     void addToIndex(QGraphicsItem *item);
     void removeFromIndex(QGraphicsItem *item);
+    void addToUnindexedItems(QGraphicsItem *item);
     void resetIndex();
 
     QGraphicsSceneBspTree bspTree;
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 55e9b34..215334c 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -47,12 +47,14 @@
 #include <QAbstractTextDocumentLayout>
 #include <QBitmap>
 #include <QCursor>
+#include <QLabel>
 #include <QDial>
 #include <QGraphicsItem>
 #include <QGraphicsScene>
 #include <QGraphicsSceneEvent>
 #include <QGraphicsView>
 #include <QGraphicsWidget>
+#include <QGraphicsProxyWidget>
 #include <QPainter>
 #include <QScrollBar>
 #include <QVBoxLayout>
@@ -196,6 +198,7 @@ private slots:
     void itemClipsChildrenToShape();
     void itemClipsChildrenToShape2();
     void itemClipsChildrenToShape3();
+    void itemClipsChildrenToShape4();
     void itemClipsTextChildToShape();
     void itemClippingDiscovery();
     void ancestorFlags();
@@ -4724,6 +4727,44 @@ void tst_QGraphicsItem::itemClipsChildrenToShape3()
     QCOMPARE(scene.itemAt(175,175), (QGraphicsItem *)0);
 }
 
+class MyProxyWidget : public QGraphicsProxyWidget
+{
+public:
+    MyProxyWidget(QGraphicsItem *parent) : QGraphicsProxyWidget(parent)
+    {
+        painted = false;
+    }
+
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
+    {
+        QGraphicsProxyWidget::paint(painter, option, widget);
+        painted = true;
+    }
+    bool painted;
+};
+
+void tst_QGraphicsItem::itemClipsChildrenToShape4()
+{
+    QGraphicsScene scene;
+    QGraphicsView view(&scene);
+
+    QGraphicsWidget * outerWidget = new QGraphicsWidget();
+    outerWidget->setFlag(QGraphicsItem::ItemClipsChildrenToShape, true);
+    MyProxyWidget * innerWidget = new MyProxyWidget(outerWidget);
+    QLabel * label = new QLabel();
+    label->setText("Welcome back my friends to the show that never ends...");
+    innerWidget->setWidget(label);
+    view.resize(300, 300);
+    scene.addItem(outerWidget);
+    outerWidget->resize( 200, 100 );
+    scene.addEllipse( 100, 100, 100, 50 );   // <-- this is important to trigger the right codepath*
+    //now the label is shown
+    outerWidget->setFlag(QGraphicsItem::ItemClipsChildrenToShape, false );
+    QApplication::setActiveWindow(&view);
+    view.show();
+    QTRY_COMPARE(QApplication::activeWindow(), (QWidget *)&view);
+    QTRY_COMPARE(innerWidget->painted, true);
+}
 
 void tst_QGraphicsItem::itemClipsTextChildToShape()
 {