Make sure the BSP is updated when a graphics effect changes bounding rect.

In the case of applying an effect to a QGraphicsItem, we have to notify
the scene's BSP that the item's bounding rect has changed. We do this
by calling prepareGeometryChange().

In the case of QWidget, it's sub-optimal that we update its parent, but
there's no other way to solve it at the moment.

4 files changed, 16 insertions, 2 deletions

diff --git a/src/gui/effects/qgraphicseffect.cpp b/src/gui/effects/qgraphicseffect.cpp
index 2be6a49..6624cfb 100644
--- a/src/gui/effects/qgraphicseffect.cpp
+++ b/src/gui/effects/qgraphicseffect.cpp
@@ -335,7 +335,7 @@ void QGraphicsEffect::setEnabled(bool enable)
 
     d->isEnabled = enable;
     if (d->source)
-        d->source->update();
+        d->source->d_func()->effectBoundingRectChanged();
     emit enabledChanged(enable);
 }
 
@@ -390,7 +390,7 @@ void QGraphicsEffect::updateBoundingRect()
 {
     Q_D(QGraphicsEffect);
     if (d->source)
-        d->source->update();
+        d->source->d_func()->effectBoundingRectChanged();
 }
 
 /*!
diff --git a/src/gui/effects/qgraphicseffect_p.h b/src/gui/effects/qgraphicseffect_p.h
index bfabfc0..24b605f 100644
--- a/src/gui/effects/qgraphicseffect_p.h
+++ b/src/gui/effects/qgraphicseffect_p.h
@@ -76,6 +76,7 @@ public:
     virtual void update() = 0;
     virtual bool isPixmap() const = 0;
     virtual QPixmap pixmap(Qt::CoordinateSystem system, QPoint *offset = 0) const = 0;
+    virtual void effectBoundingRectChanged() = 0;
     friend class QGraphicsScenePrivate;
     friend class QGraphicsItem;
     friend class QGraphicsItemPrivate;
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index 1090620..49361cf 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -572,6 +572,9 @@ public:
     inline void update()
     { item->update(); }
 
+    inline void effectBoundingRectChanged()
+    { item->prepareGeometryChange(); }
+
     inline bool isPixmap() const
     {
         return (item->type() == QGraphicsPixmapItem::Type);
diff --git a/src/gui/kernel/qwidget_p.h b/src/gui/kernel/qwidget_p.h
index ff0c453..f69c3a7 100644
--- a/src/gui/kernel/qwidget_p.h
+++ b/src/gui/kernel/qwidget_p.h
@@ -727,6 +727,16 @@ public:
     inline bool isPixmap() const
     { return false; }
 
+    inline void effectBoundingRectChanged()
+    {
+        // ### This function should take a rect parameter; then we can avoid
+        // updating too much on the parent widget.
+        if (QWidget *parent = m_widget->parentWidget())
+            parent->update();
+        else
+            m_widget->update();
+    }
+
     inline const QStyleOption *styleOption() const
     { return 0; }