Painting artifacts in QGraphicsView.

Problem appears in the chip demo when clicking an item while scrolling the
view using the mouse wheel. The problem was that we didn't translate the
the item's old painted view rect.

There was also a problem when enabling the DontAdjustForAntialiasing flag,
causing an item to not redraw its edges. We have to adjust the rectangle
by (-1, -1, 1, 1) since QRect() and QRectF() behaves differently.

Auto-test (made by Andreas) included.

Reviewed-by: Andreas

1 files changed, 63 insertions, 0 deletions

diff --git a/tests/auto/qgraphicsview/tst_qgraphicsview.cpp b/tests/auto/qgraphicsview/tst_qgraphicsview.cpp
index 5167682..06b4a78 100644
--- a/tests/auto/qgraphicsview/tst_qgraphicsview.cpp
+++ b/tests/auto/qgraphicsview/tst_qgraphicsview.cpp
@@ -188,6 +188,8 @@ private slots:
     void embeddedViews();
     void scrollAfterResize_data();
     void scrollAfterResize();
+    void moveItemWhileScrolling_data();
+    void moveItemWhileScrolling();
     void centerOnDirtyItem();
     void mouseTracking();
     void mouseTracking2();
@@ -3045,6 +3047,67 @@ void tst_QGraphicsView::scrollAfterResize()
     QCOMPARE(view.viewportTransform(), x3);
 }
 
+void tst_QGraphicsView::moveItemWhileScrolling_data()
+{
+    QTest::addColumn<bool>("adjustForAntialiasing");
+
+    QTest::newRow("no adjust") << false;
+    QTest::newRow("adjust") << true;
+}
+
+void tst_QGraphicsView::moveItemWhileScrolling()
+{
+    QFETCH(bool, adjustForAntialiasing);
+
+    class MoveItemScrollView : public QGraphicsView
+    {
+    public:
+        MoveItemScrollView()
+        {
+            setScene(new QGraphicsScene(0, 0, 1000, 1000));
+            rect = scene()->addRect(0, 0, 10, 10);
+            rect->setPos(50, 50);
+        }
+        QRegion lastPaintedRegion;
+        QGraphicsItem *rect;
+    protected:
+        void paintEvent(QPaintEvent *event)
+        {
+            lastPaintedRegion = event->region();
+            QGraphicsView::paintEvent(event);
+        }
+    };
+
+    MoveItemScrollView view;
+    view.setFrameStyle(0);
+    view.setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    view.setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    view.setResizeAnchor(QGraphicsView::NoAnchor);
+    view.setTransformationAnchor(QGraphicsView::NoAnchor);
+    if (!adjustForAntialiasing)
+        view.setOptimizationFlag(QGraphicsView::DontAdjustForAntialiasing);
+    view.show();
+    view.resize(200, 200);
+#ifdef Q_WS_X11
+    qt_x11_wait_for_window_manager(&view);
+#endif
+    QTest::qWait(100);
+
+    view.lastPaintedRegion = QRegion();
+    view.horizontalScrollBar()->setValue(view.horizontalScrollBar()->value() + 10);
+    view.rect->moveBy(0, 10);
+    QTest::qWait(100);
+
+    QRegion expectedRegion;
+    expectedRegion += QRect(0, 0, 200, 200);
+    expectedRegion -= QRect(0, 0, 190, 200);
+    int a = adjustForAntialiasing ? 2 : 1;
+    expectedRegion += QRect(40, 50, 10, 10).adjusted(-a, -a, a, a);
+    expectedRegion += QRect(40, 60, 10, 10).adjusted(-a, -a, a, a);
+
+    QCOMPARE(view.lastPaintedRegion, expectedRegion);
+}
+
 void tst_QGraphicsView::centerOnDirtyItem()
 {
     QGraphicsView view;