3 files changed, 64 insertions, 16 deletions

diff --git a/src/gui/effects/qgraphicseffect.cpp b/src/gui/effects/qgraphicseffect.cpp
index f24d424..3b94a5d 100644
--- a/src/gui/effects/qgraphicseffect.cpp
+++ b/src/gui/effects/qgraphicseffect.cpp
@@ -212,7 +212,23 @@ const QStyleOption *QGraphicsEffectSource::styleOption() const
 */
 void QGraphicsEffectSource::draw(QPainter *painter)
 {
-    d_func()->draw(painter);
+    Q_D(const QGraphicsEffectSource);
+
+    QPixmap pm;
+    if (QPixmapCache::find(d->m_cacheKey, &pm)) {
+        QTransform restoreTransform;
+        if (d->m_cachedSystem == Qt::DeviceCoordinates) {
+            restoreTransform = painter->worldTransform();
+            painter->setWorldTransform(QTransform());
+        }
+
+        painter->drawPixmap(d->m_cachedOffset, pm);
+
+        if (d->m_cachedSystem == Qt::DeviceCoordinates)
+            painter->setWorldTransform(restoreTransform);
+    } else {
+        d_func()->draw(painter);
+    }
 }
 
 /*!
@@ -287,6 +303,13 @@ QPixmap QGraphicsEffectSource::pixmap(Qt::CoordinateSystem system, QPoint *offse
     return pm;
 }
 
+void QGraphicsEffectSourcePrivate::invalidateCache(bool effectRectChanged) const
+{
+    if (effectRectChanged && m_cachedMode != QGraphicsEffectSource::ExpandToEffectRectPadMode)
+        return;
+    QPixmapCache::remove(m_cacheKey);
+}
+
 /*!
     Constructs a new QGraphicsEffect instance having the
     specified \a parent.
@@ -426,7 +449,7 @@ void QGraphicsEffect::updateBoundingRect()
     Q_D(QGraphicsEffect);
     if (d->source) {
         d->source->d_func()->effectBoundingRectChanged();
-        d->source->d_func()->invalidateCache();
+        d->source->d_func()->invalidateCache(true);
     }
 }
 
@@ -614,6 +637,26 @@ void QGraphicsColorizeEffect::draw(QPainter *painter, QGraphicsEffectSource *sou
 */
 
 /*!
+    \enum QGraphicsBlurEffect::BlurHint
+    \since 4.6
+
+    This enum describes the possible hints that can be used to control how
+    blur effects are applied. The hints might not have an effect in all the
+    paint engines.
+
+    \value QualityHint Indicates that rendering quality is the most important factor,
+    at the potential cost of lower performance.
+
+    \value PerformanceHint Indicates that rendering performance is the most important factor,
+    at the potential cost of lower quality.
+
+    \value AnimationHint Indicates that the blur radius is going to be animated, hinting
+    that the implementation can keep a cache of blurred verisons of the source pixmap.
+    Do not use this hint if the source item is going to be dynamically changing.
+*/
+
+
+/*!
     Constructs a new QGraphicsBlurEffect instance.
     The \a parent parameter is passed to QGraphicsEffect's constructor.
 */
@@ -621,7 +664,7 @@ QGraphicsBlurEffect::QGraphicsBlurEffect(QObject *parent)
     : QGraphicsEffect(*new QGraphicsBlurEffectPrivate, parent)
 {
     Q_D(QGraphicsBlurEffect);
-    d->filter->setBlurHint(Qt::PerformanceHint);
+    d->filter->setBlurHint(QGraphicsBlurEffect::PerformanceHint);
 }
 
 /*!
@@ -668,20 +711,19 @@ void QGraphicsBlurEffect::setBlurRadius(qreal radius)
     \property QGraphicsBlurEffect::blurHint
     \brief the blur hint of the effect.
 
-    Use the Qt::PerformanceHint hint to say that you want a faster blur,
-    and the Qt::QualityHint hint to say that you prefer a higher quality blur.
-
-    When animating the blur radius it's recommended to use Qt::PerformanceHint.
+    Use the PerformanceHint hint to say that you want a faster blur,
+    the QualityHint hint to say that you prefer a higher quality blur,
+    or the AnimationHint when you want to animate the blur radius.
 
-    By default, the blur hint is Qt::PerformanceHint.
+    By default, the blur hint is PerformanceHint.
 */
-Qt::RenderHint QGraphicsBlurEffect::blurHint() const
+QGraphicsBlurEffect::BlurHint QGraphicsBlurEffect::blurHint() const
 {
     Q_D(const QGraphicsBlurEffect);
     return d->filter->blurHint();
 }
 
-void QGraphicsBlurEffect::setBlurHint(Qt::RenderHint hint)
+void QGraphicsBlurEffect::setBlurHint(QGraphicsBlurEffect::BlurHint hint)
 {
     Q_D(QGraphicsBlurEffect);
     if (d->filter->blurHint() == hint)
@@ -692,7 +734,7 @@ void QGraphicsBlurEffect::setBlurHint(Qt::RenderHint hint)
 }
 
 /*!
-    \fn void QGraphicsBlurEffect::blurHintChanged(Qt::RenderHint hint)
+    \fn void QGraphicsBlurEffect::blurHintChanged(Qt::BlurHint hint)
 
     This signal is emitted whenever the effect's blur hint changes.
     The \a hint parameter holds the effect's new blur hint.
diff --git a/src/gui/effects/qgraphicseffect.h b/src/gui/effects/qgraphicseffect.h
index bf18581..7335a25 100644
--- a/src/gui/effects/qgraphicseffect.h
+++ b/src/gui/effects/qgraphicseffect.h
@@ -183,22 +183,28 @@ class Q_GUI_EXPORT QGraphicsBlurEffect: public QGraphicsEffect
 {
     Q_OBJECT
     Q_PROPERTY(qreal blurRadius READ blurRadius WRITE setBlurRadius NOTIFY blurRadiusChanged)
-    Q_PROPERTY(Qt::RenderHint blurHint READ blurHint WRITE setBlurHint NOTIFY blurHintChanged)
+    Q_PROPERTY(BlurHint blurHint READ blurHint WRITE setBlurHint NOTIFY blurHintChanged)
 public:
+    enum BlurHint {
+        QualityHint,
+        PerformanceHint,
+        AnimationHint
+    };
+
     QGraphicsBlurEffect(QObject *parent = 0);
     ~QGraphicsBlurEffect();
 
     QRectF boundingRectFor(const QRectF &rect) const;
     qreal blurRadius() const;
-    Qt::RenderHint blurHint() const;
+    BlurHint blurHint() const;
 
 public Q_SLOTS:
     void setBlurRadius(qreal blurRadius);
-    void setBlurHint(Qt::RenderHint hint);
+    void setBlurHint(BlurHint hint);
 
 Q_SIGNALS:
     void blurRadiusChanged(qreal blurRadius);
-    void blurHintChanged(Qt::RenderHint hint);
+    void blurHintChanged(BlurHint hint);
 
 protected:
     void draw(QPainter *painter, QGraphicsEffectSource *source);
diff --git a/src/gui/effects/qgraphicseffect_p.h b/src/gui/effects/qgraphicseffect_p.h
index 1ed7103..0ff5794 100644
--- a/src/gui/effects/qgraphicseffect_p.h
+++ b/src/gui/effects/qgraphicseffect_p.h
@@ -85,7 +85,7 @@ public:
     virtual QPixmap pixmap(Qt::CoordinateSystem system, QPoint *offset = 0,
                            QGraphicsEffectSource::PixmapPadMode mode = QGraphicsEffectSource::ExpandToTransparentBorderPadMode) const = 0;
     virtual void effectBoundingRectChanged() = 0;
-    void invalidateCache() const { QPixmapCache::remove(m_cacheKey); }
+    void invalidateCache(bool effectRectChanged = false) const;
 
     friend class QGraphicsScenePrivate;
     friend class QGraphicsItem;