qt 6.5.1 original

tests/auto/widgets/effects/qgraphicseffect/BLACKLIST

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+[draw]
+wayland

tests/auto/widgets/effects/qgraphicseffect/CMakeLists.txt

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+# Copyright (C) 2022 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_qgraphicseffect Test:
+#####################################################################
+
+qt_internal_add_test(tst_qgraphicseffect
+    SOURCES
+        tst_qgraphicseffect.cpp
+    LIBRARIES
+        Qt::CorePrivate
+        Qt::Gui
+        Qt::GuiPrivate
+        Qt::Widgets
+        Qt::WidgetsPrivate
+)

tests/auto/widgets/effects/qgraphicseffect/tst_qgraphicseffect.cpp

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+// Copyright (C) 2016 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0
+
+
+#include <QtTest/QtTestWidgets>
+#include <QtWidgets/qgraphicseffect.h>
+#include <QtWidgets/qgraphicsview.h>
+#include <QtWidgets/qgraphicsscene.h>
+#include <QtWidgets/qgraphicsitem.h>
+#include <QtWidgets/qgraphicswidget.h>
+#include <QtWidgets/qstyleoption.h>
+
+#include <private/qgraphicseffect_p.h>
+
+class tst_QGraphicsEffect : public QObject
+{
+    Q_OBJECT
+public slots:
+    void initTestCase();
+
+private slots:
+    void setEnabled();
+    void source();
+    void boundingRectFor();
+    void boundingRect();
+    void boundingRect2();
+    void draw();
+    void opacity();
+    void grayscale();
+    void colorize();
+    void drawPixmapItem();
+    void deviceCoordinateTranslateCaching();
+    void inheritOpacity();
+    void dropShadowClipping();
+    void childrenVisibilityShouldInvalidateCache();
+    void prepareGeometryChangeInvalidateCache();
+    void itemHasNoContents();
+};
+
+void tst_QGraphicsEffect::initTestCase()
+{}
+
+class CustomItem : public QGraphicsRectItem
+{
+public:
+    CustomItem(qreal x, qreal y, qreal width, qreal height, QGraphicsItem *parent = nullptr)
+        : QGraphicsRectItem(x, y, width, height, parent), numRepaints(0),
+          m_painter(nullptr), m_styleOption(nullptr)
+    {}
+
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
+    {
+        m_painter = painter;
+        m_styleOption = option;
+        ++numRepaints;
+        QGraphicsRectItem::paint(painter, option, widget);
+    }
+
+    void reset()
+    {
+        numRepaints = 0;
+        m_painter = nullptr;
+        m_styleOption = nullptr;
+    }
+
+    int numRepaints;
+    QPainter *m_painter;
+    const QStyleOption *m_styleOption;
+};
+
+class CustomEffect : public QGraphicsEffect
+{
+public:
+    CustomEffect()
+        : QGraphicsEffect(), numRepaints(0), m_margin(10),
+          doNothingInDraw(false), m_painter(nullptr), m_styleOption(nullptr),
+          m_source(nullptr), m_opacity(1.0)
+    {}
+
+    QRectF boundingRectFor(const QRectF &rect) const override
+    { return rect.adjusted(-m_margin, -m_margin, m_margin, m_margin); }
+
+    void reset()
+    {
+        numRepaints = 0;
+        m_sourceChangedFlags = QGraphicsEffect::ChangeFlags();
+        m_painter = nullptr;
+        m_styleOption = nullptr;
+        m_source = nullptr;
+        m_opacity = 1.0;
+    }
+
+    void setMargin(int margin)
+    {
+        m_margin = margin;
+        updateBoundingRect();
+    }
+
+    int margin() const
+    { return m_margin; }
+
+    void draw(QPainter *painter) override
+    {
+        ++numRepaints;
+        if (doNothingInDraw)
+            return;
+        m_source = source();
+        m_painter = painter;
+        m_styleOption = source()->styleOption();
+        m_opacity = painter->opacity();
+        drawSource(painter);
+    }
+
+    void sourceChanged(QGraphicsEffect::ChangeFlags flags) override
+    { m_sourceChangedFlags |= flags; }
+
+    int numRepaints;
+    int m_margin;
+    QGraphicsEffect::ChangeFlags m_sourceChangedFlags;
+    bool doNothingInDraw;
+    QPainter *m_painter;
+    const QStyleOption *m_styleOption;
+    QGraphicsEffectSource *m_source;
+    qreal m_opacity;
+};
+
+void tst_QGraphicsEffect::setEnabled()
+{
+    CustomEffect effect;
+    QVERIFY(effect.isEnabled());
+
+    effect.setEnabled(false);
+    QVERIFY(!effect.isEnabled());
+}
+
+void tst_QGraphicsEffect::source()
+{
+    QPointer<CustomEffect> effect = new CustomEffect;
+    QVERIFY(!effect->source());
+    QVERIFY(!effect->m_sourceChangedFlags);
+
+    // Install effect on QGraphicsItem.
+    QGraphicsItem *item = new QGraphicsRectItem(0, 0, 10, 10);
+    item->setGraphicsEffect(effect);
+    QVERIFY(effect->source());
+    QCOMPARE(effect->source()->graphicsItem(), (const QGraphicsItem*)item);
+    QVERIFY(effect->m_sourceChangedFlags & QGraphicsEffect::SourceAttached);
+    effect->reset();
+
+    // Make sure disabling/enabling the effect doesn't change the source.
+    effect->setEnabled(false);
+    QVERIFY(effect->source());
+    QCOMPARE(effect->source()->graphicsItem(), (const QGraphicsItem*)item);
+    QVERIFY(!effect->m_sourceChangedFlags);
+    effect->reset();
+
+    effect->setEnabled(true);
+    QVERIFY(effect->source());
+    QCOMPARE(effect->source()->graphicsItem(), (const QGraphicsItem*)item);
+    QVERIFY(!effect->m_sourceChangedFlags);
+    effect->reset();
+
+    // Uninstall effect on QGraphicsItem.
+    effect->reset();
+    item->setGraphicsEffect(0);
+    QVERIFY(!effect);
+    effect = new CustomEffect;
+
+    // The item takes ownership and should delete the effect when destroyed.
+    item->setGraphicsEffect(effect);
+    QPointer<QGraphicsEffectSource> source = effect->source();
+    QVERIFY(source);
+    QCOMPARE(source->graphicsItem(), (const QGraphicsItem*)item);
+    delete item;
+    QVERIFY(!effect);
+    QVERIFY(!source);
+}
+
+void tst_QGraphicsEffect::boundingRectFor()
+{
+    CustomEffect effect;
+    int margin = effect.margin();
+    const QRectF source(0, 0, 100, 100);
+    QCOMPARE(effect.boundingRectFor(source), source.adjusted(-margin, -margin, margin, margin));
+
+    effect.setMargin(margin = 20);
+    QCOMPARE(effect.boundingRectFor(source), source.adjusted(-margin, -margin, margin, margin));
+}
+
+void tst_QGraphicsEffect::boundingRect()
+{
+    // No source; empty bounding rect.
+    CustomEffect *effect = new CustomEffect;
+    QCOMPARE(effect->boundingRect(), QRectF());
+
+    // Install effect on QGraphicsItem.
+    QRectF itemRect(0, 0, 100, 100);
+    QGraphicsRectItem *item = new QGraphicsRectItem;
+    item->setPen(QPen(Qt::black, 0));
+    item->setRect(itemRect);
+    item->setGraphicsEffect(effect);
+    int margin = effect->margin();
+    QCOMPARE(effect->boundingRect(), itemRect.adjusted(-margin, -margin, margin, margin));
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(itemRect));
+
+    // Make sure disabling/enabling the effect doesn't change the bounding rect.
+    effect->setEnabled(false);
+    QCOMPARE(effect->boundingRect(), itemRect.adjusted(-margin, -margin, margin, margin));
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(itemRect));
+    effect->setEnabled(true);
+    QCOMPARE(effect->boundingRect(), itemRect.adjusted(-margin, -margin, margin, margin));
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(itemRect));
+
+    // Change effect margins.
+    effect->setMargin(margin = 20);
+    QCOMPARE(effect->boundingRect(), itemRect.adjusted(-margin, -margin, margin, margin));
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(itemRect));
+
+    // Uninstall effect on QGraphicsItem.
+    QPointer<CustomEffect> ptr = effect;
+    item->setGraphicsEffect(0);
+    QVERIFY(!ptr);
+
+    delete item;
+}
+
+void tst_QGraphicsEffect::boundingRect2()
+{
+    CustomEffect *effect = new CustomEffect;
+    QGraphicsRectItem *root = new QGraphicsRectItem;
+    root->setPen(QPen(Qt::black, 0));
+    root->setGraphicsEffect(effect);
+
+    QGraphicsRectItem *child = new QGraphicsRectItem;
+    QRectF childRect(0, 0, 100, 100);
+    child->setPen(QPen(Qt::black, 0));
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape);
+    child->setRect(childRect);
+    child->setParentItem(root);
+
+    QGraphicsRectItem *grandChild = new QGraphicsRectItem;
+    QRectF grandChildRect(0, 0, 200, 200);
+    grandChild->setPen(QPen(Qt::black, 0));
+    grandChild->setRect(grandChildRect);
+    grandChild->setParentItem(child);
+
+    // Make sure the effect's bounding rect is clipped to the child's bounding rect.
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect));
+
+    // Disable ItemClipsChildrenToShape; effect's bounding rect is no longer clipped.
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape, false);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect | grandChildRect));
+
+    // Add root item to a scene, do the same tests as above. Results should be the same.
+    QGraphicsScene scene;
+    scene.addItem(root);
+
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect));
+
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape, false);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect | grandChildRect));
+
+    // Now add the scene to a view, results should be the same.
+    QGraphicsView view(&scene);
+
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect));
+
+    child->setFlag(QGraphicsItem::ItemClipsChildrenToShape, false);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect | grandChildRect));
+
+    CustomEffect *childEffect = new CustomEffect;
+    child->setGraphicsEffect(childEffect);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childEffect->boundingRectFor(childRect | grandChildRect)));
+
+    child->setGraphicsEffect(0);
+    QCOMPARE(effect->boundingRect(), effect->boundingRectFor(childRect | grandChildRect));
+}
+
+void tst_QGraphicsEffect::draw()
+{
+    QGraphicsScene scene;
+    CustomItem *item = new CustomItem(0, 0, 100, 100);
+    scene.addItem(item);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(item->numRepaints > 0);
+    QCoreApplication::processEvents(); // Process all queued paint events
+    item->reset();
+
+    // Make sure installing the effect triggers a repaint.
+    CustomEffect *effect = new CustomEffect;
+    item->setGraphicsEffect(effect);
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QTRY_COMPARE(item->numRepaints, 1);
+
+    // Make sure QPainter* and QStyleOptionGraphicsItem* stays persistent
+    // during QGraphicsEffect::draw/QGraphicsItem::paint.
+    QVERIFY(effect->m_painter);
+    QCOMPARE(effect->m_painter, item->m_painter);
+    QCOMPARE(effect->m_styleOption, item->m_styleOption);
+    // Make sure QGraphicsEffect::source is persistent.
+    QCOMPARE(effect->m_source, effect->source());
+    effect->reset();
+    item->reset();
+
+    // Make sure updating the source triggers a repaint.
+    item->update();
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QTRY_COMPARE(item->numRepaints, 1);
+    QVERIFY(effect->m_sourceChangedFlags & QGraphicsEffect::SourceInvalidated);
+    effect->reset();
+    item->reset();
+
+    // Make sure changing the effect's bounding rect triggers a repaint.
+    effect->setMargin(20);
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QTRY_COMPARE(item->numRepaints, 1);
+    effect->reset();
+    item->reset();
+
+    // Make sure change the item's bounding rect triggers a repaint.
+    item->setRect(0, 0, 50, 50);
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QTRY_COMPARE(item->numRepaints, 1);
+    QVERIFY(effect->m_sourceChangedFlags & QGraphicsEffect::SourceBoundingRectChanged);
+    effect->reset();
+    item->reset();
+
+    // Make sure the effect is the one to issue a repaint of the item.
+    effect->doNothingInDraw = true;
+    item->update();
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QCOMPARE(item->numRepaints, 0);
+    effect->doNothingInDraw = false;
+    effect->reset();
+    item->reset();
+
+    // Make sure we update the source when disabling/enabling the effect.
+    effect->setEnabled(false);
+    QTRY_COMPARE(item->numRepaints, 1);
+    QCOMPARE(effect->numRepaints, 0);
+    effect->reset();
+    item->reset();
+
+    effect->setEnabled(true);
+    QTRY_COMPARE(effect->numRepaints, 1);
+    QTRY_COMPARE(item->numRepaints, 1);
+    effect->reset();
+    item->reset();
+
+    // Effect is already enabled; nothing should happen.
+    effect->setEnabled(true);
+    QTest::qWait(50);
+    QCOMPARE(effect->numRepaints, 0);
+    QCOMPARE(item->numRepaints, 0);
+
+    // Make sure uninstalling an effect triggers a repaint.
+    QPointer<CustomEffect> ptr = effect;
+    item->setGraphicsEffect(0);
+    QVERIFY(!ptr);
+    QTRY_COMPARE(item->numRepaints, 1);
+}
+
+void tst_QGraphicsEffect::opacity()
+{
+    // Make sure the painter's opacity is correct in QGraphicsEffect::draw.
+    QGraphicsScene scene;
+    CustomItem *item = new CustomItem(0, 0, 100, 100);
+    item->setOpacity(0.5);
+    CustomEffect *effect = new CustomEffect;
+    item->setGraphicsEffect(effect);
+    scene.addItem(item);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(effect->numRepaints > 0);
+    QCOMPARE(effect->m_opacity, qreal(0.5));
+}
+
+void tst_QGraphicsEffect::grayscale()
+{
+    if (QGuiApplication::primaryScreen()->depth() < 24)
+        QSKIP("Test only works on 32 bit displays");
+
+    QGraphicsScene scene(0, 0, 100, 100);
+
+    QGraphicsRectItem *item = scene.addRect(0, 0, 50, 50);
+    item->setPen(Qt::NoPen);
+    item->setBrush(QColor(122, 193, 66)); // Qt light green
+
+    QGraphicsColorizeEffect *effect = new QGraphicsColorizeEffect;
+    effect->setColor(Qt::black);
+    item->setGraphicsEffect(effect);
+
+    QPainter painter;
+    QImage image(100, 100, QImage::Format_ARGB32_Premultiplied);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(148, 148, 148));
+
+    effect->setStrength(0.5);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(135, 171, 107));
+
+    effect->setStrength(0.0);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(122, 193, 66));
+}
+
+void tst_QGraphicsEffect::colorize()
+{
+    if (QGuiApplication::primaryScreen()->depth() < 24)
+        QSKIP("Test only works on 32 bit displays");
+
+    QGraphicsScene scene(0, 0, 100, 100);
+
+    QGraphicsRectItem *item = scene.addRect(0, 0, 50, 50);
+    item->setPen(Qt::NoPen);
+    item->setBrush(QColor(122, 193, 66)); // Qt light green
+
+    QGraphicsColorizeEffect *effect = new QGraphicsColorizeEffect;
+    effect->setColor(QColor(102, 153, 51)); // Qt dark green
+    item->setGraphicsEffect(effect);
+
+    QPainter painter;
+    QImage image(100, 100, QImage::Format_ARGB32_Premultiplied);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(191, 212, 169));
+
+    effect->setStrength(0.5);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(156, 203, 117));
+
+    effect->setStrength(0.0);
+
+    image.fill(0);
+    painter.begin(&image);
+    painter.setRenderHint(QPainter::Antialiasing);
+    scene.render(&painter);
+    painter.end();
+
+    QCOMPARE(image.pixel(10, 10), qRgb(122, 193, 66));
+}
+
+class PixmapItemEffect : public QGraphicsEffect
+{
+public:
+    PixmapItemEffect(const QPixmap &source)
+        : QGraphicsEffect()
+        , pixmap(source)
+        , repaints(0)
+    {}
+
+    QRectF boundingRectFor(const QRectF &rect) const override
+    { return rect; }
+
+    void draw(QPainter *painter) override
+    {
+        QCOMPARE(sourcePixmap(Qt::LogicalCoordinates).handle(), pixmap.handle());
+        QVERIFY((painter->worldTransform().type() <= QTransform::TxTranslate) == (sourcePixmap(Qt::DeviceCoordinates).handle() == pixmap.handle()));
+
+        ++repaints;
+    }
+    QPixmap pixmap;
+    int repaints;
+};
+
+void tst_QGraphicsEffect::drawPixmapItem()
+{
+    QImage image(32, 32, QImage::Format_RGB32);
+    QPainter p(&image);
+    p.fillRect(0, 0, 32, 16, Qt::blue);
+    p.fillRect(0, 16, 32, 16, Qt::red);
+    p.end();
+
+    QGraphicsScene scene;
+    QGraphicsPixmapItem *item = new QGraphicsPixmapItem(QPixmap::fromImage(image));
+    scene.addItem(item);
+
+    PixmapItemEffect *effect = new PixmapItemEffect(item->pixmap());
+    item->setGraphicsEffect(effect);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(effect->repaints >= 1);
+
+    item->setTransform(QTransform().rotate(180), true);
+
+    QTRY_VERIFY(effect->repaints >= 2);
+}
+
+class DeviceEffect : public QGraphicsEffect
+{
+public:
+    QRectF boundingRectFor(const QRectF &rect) const override
+    { return rect; }
+
+    void draw(QPainter *painter) override
+    {
+        QPoint offset;
+        QPixmap pixmap = sourcePixmap(Qt::DeviceCoordinates, &offset, QGraphicsEffect::NoPad);
+
+        if (pixmap.isNull())
+            return;
+
+        painter->save();
+        painter->setWorldTransform(QTransform());
+        painter->drawPixmap(offset, pixmap);
+        painter->restore();
+    }
+};
+
+void tst_QGraphicsEffect::deviceCoordinateTranslateCaching()
+{
+    QGraphicsScene scene;
+    CustomItem *item = new CustomItem(0, 0, 10, 10);
+    scene.addItem(item);
+    scene.setSceneRect(0, 0, 50, 0);
+
+    item->setGraphicsEffect(new DeviceEffect);
+    item->setPen(Qt::NoPen);
+    item->setBrush(Qt::red);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+
+    QTRY_VERIFY(item->numRepaints >= 1);
+    int numRepaints = item->numRepaints;
+
+    item->setTransform(QTransform::fromTranslate(10, 0), true);
+
+    QTRY_COMPARE(item->numRepaints, numRepaints);
+}
+
+void tst_QGraphicsEffect::inheritOpacity()
+{
+    QGraphicsScene scene;
+    QGraphicsRectItem *rectItem = new QGraphicsRectItem(0, 0, 10, 10);
+    CustomItem *item = new CustomItem(0, 0, 10, 10, rectItem);
+
+    scene.addItem(rectItem);
+
+    item->setGraphicsEffect(new DeviceEffect);
+    item->setPen(Qt::NoPen);
+    item->setBrush(Qt::red);
+
+    rectItem->setOpacity(0.5);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+
+    QTRY_VERIFY(item->numRepaints >= 1);
+
+    int numRepaints = item->numRepaints;
+
+    rectItem->setOpacity(1);
+
+    // item should have been rerendered due to opacity changing
+    QTRY_VERIFY(item->numRepaints > numRepaints);
+}
+
+void tst_QGraphicsEffect::dropShadowClipping()
+{
+    QImage img(128, 128, QImage::Format_ARGB32_Premultiplied);
+    img.fill(0xffffffff);
+
+    QGraphicsScene scene;
+    QGraphicsRectItem *item = new QGraphicsRectItem(-5, -500, 10, 1000);
+    item->setGraphicsEffect(new QGraphicsDropShadowEffect);
+    item->setPen(Qt::NoPen);
+    item->setBrush(Qt::red);
+
+    scene.addItem(item);
+
+    QPainter p(&img);
+    scene.render(&p, img.rect(), QRect(-64, -64, 128, 128));
+    p.end();
+
+    for (int y = 1; y < img.height(); ++y)
+        for (int x = 0; x < img.width(); ++x)
+            QCOMPARE(img.pixel(x, y), img.pixel(x, y-1));
+}
+
+class MyGraphicsItem : public QGraphicsWidget
+{
+public:
+    MyGraphicsItem(QGraphicsItem *parent = nullptr) :
+            QGraphicsWidget(parent), nbPaint(0)
+    {}
+    void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override
+    {
+        nbPaint++;
+        QGraphicsWidget::paint(painter, option, widget);
+    }
+    int nbPaint;
+};
+
+void tst_QGraphicsEffect::childrenVisibilityShouldInvalidateCache()
+{
+    QGraphicsScene scene;
+    MyGraphicsItem parent;
+    parent.resize(200, 200);
+    QGraphicsWidget child(&parent);
+    child.resize(200, 200);
+    child.setVisible(false);
+    scene.addItem(&parent);
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(parent.nbPaint >= 1);
+    //we set an effect on the parent
+    parent.setGraphicsEffect(new QGraphicsDropShadowEffect(&parent));
+    //flush the events
+    QApplication::processEvents();
+    //new effect applied->repaint
+    QVERIFY(parent.nbPaint >= 2);
+    child.setVisible(true);
+    //flush the events
+    QApplication::processEvents();
+    //a new child appears we need to redraw the effect.
+    QVERIFY(parent.nbPaint >= 3);
+}
+
+void tst_QGraphicsEffect::prepareGeometryChangeInvalidateCache()
+{
+    MyGraphicsItem *item = new MyGraphicsItem;
+    item->resize(200, 200);
+
+    QGraphicsScene scene;
+    scene.addItem(item);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(view.windowHandle()->isActive());
+    QTRY_VERIFY(item->nbPaint >= 1);
+
+    item->nbPaint = 0;
+    item->setGraphicsEffect(new QGraphicsDropShadowEffect);
+    QTRY_COMPARE(item->nbPaint, 1);
+
+    item->nbPaint = 0;
+    item->resize(300, 300);
+    QTRY_COMPARE(item->nbPaint, 1);
+
+    item->nbPaint = 0;
+    item->setPos(item->pos() + QPointF(10, 10));
+    QTest::qWait(50);
+    QCOMPARE(item->nbPaint, 0);
+}
+
+void tst_QGraphicsEffect::itemHasNoContents()
+{
+    QGraphicsRectItem *parent = new QGraphicsRectItem;
+    parent->setFlag(QGraphicsItem::ItemHasNoContents);
+
+    MyGraphicsItem *child = new MyGraphicsItem;
+    child->setParentItem(parent);
+    child->resize(200, 200);
+
+    QGraphicsScene scene;
+    scene.addItem(parent);
+
+    QGraphicsView view(&scene);
+    view.show();
+    QVERIFY(QTest::qWaitForWindowExposed(&view));
+    QTRY_VERIFY(child->nbPaint >= 1);
+
+    CustomEffect *effect = new CustomEffect;
+    parent->setGraphicsEffect(effect);
+    QTRY_VERIFY(effect->numRepaints >= 1);
+
+    for (int i = 0; i < 3; ++i) {
+        effect->reset();
+        effect->update();
+        QTRY_VERIFY(effect->numRepaints >= 1);
+    }
+}
+
+QTEST_MAIN(tst_QGraphicsEffect)
+#include "tst_qgraphicseffect.moc"
+