Merge branch '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.6-integration

* '4.6' of scm.dev.nokia.troll.no:qt/oslo-staging-2:
  Prevents a useless repaint with QGraphicsItem cache mode.

2 files changed, 75 insertions, 1 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index f110a5c..1b707b0 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -1883,7 +1883,8 @@ void QGraphicsItem::setCacheMode(CacheMode mode, const QSize &logicalCacheSize)
     d_ptr->cacheMode = mode;
     bool noVisualChange = (mode == NoCache && lastMode == NoCache)
                           || (mode == NoCache && lastMode == DeviceCoordinateCache)
-                          || (mode == DeviceCoordinateCache && lastMode == NoCache);
+                          || (mode == DeviceCoordinateCache && lastMode == NoCache)
+                          || (mode == DeviceCoordinateCache && lastMode == DeviceCoordinateCache);
     if (mode == NoCache) {
         d_ptr->removeExtraItemCache();
     } else {
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 75fb337..2b507cb 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -384,6 +384,7 @@ private slots:
     void tabChangesFocus();
     void tabChangesFocus_data();
     void cacheMode();
+    void cacheMode2();
     void updateCachedItemAfterMove();
     void deviceTransform_data();
     void deviceTransform();
@@ -6926,6 +6927,78 @@ void tst_QGraphicsItem::cacheMode()
     QCOMPARE(testerChild2->repaints, 6);
 }
 
+void tst_QGraphicsItem::cacheMode2()
+{
+    QGraphicsScene scene(0, 0, 100, 100);
+    QGraphicsView view(&scene);
+    view.resize(150, 150);
+    view.show();
+    QApplication::setActiveWindow(&view);
+    QTest::qWaitForWindowShown(&view);
+
+    // Increase the probability of window activation
+    // not causing another repaint of test items.
+    QTest::qWait(50);
+
+    EventTester *tester = new EventTester;
+    scene.addItem(tester);
+    QTest::qWait(10);
+    QTRY_COMPARE(tester->repaints, 1);
+
+    // Switching from NoCache to NoCache (no repaint)
+    tester->setCacheMode(QGraphicsItem::NoCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 1);
+
+    // Switching from NoCache to DeviceCoordinateCache (no repaint)
+    tester->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 1);
+
+    // Switching from DeviceCoordinateCache to DeviceCoordinateCache (no repaint)
+    tester->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 1);
+
+    // Switching from DeviceCoordinateCache to NoCache (no repaint)
+    tester->setCacheMode(QGraphicsItem::NoCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 1);
+
+    // Switching from NoCache to ItemCoordinateCache (repaint)
+    tester->setCacheMode(QGraphicsItem::ItemCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 2);
+
+    // Switching from ItemCoordinateCache to ItemCoordinateCache (no repaint)
+    tester->setCacheMode(QGraphicsItem::ItemCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 2);
+
+    // Switching from ItemCoordinateCache to ItemCoordinateCache with different size (repaint)
+    tester->setCacheMode(QGraphicsItem::ItemCoordinateCache, QSize(100, 100));
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 3);
+
+    // Switching from ItemCoordinateCache to NoCache (repaint)
+    tester->setCacheMode(QGraphicsItem::NoCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 4);
+
+    // Switching from DeviceCoordinateCache to ItemCoordinateCache (repaint)
+    tester->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 4);
+    tester->setCacheMode(QGraphicsItem::ItemCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 5);
+
+    // Switching from ItemCoordinateCache to DeviceCoordinateCache (repaint)
+    tester->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
+    QTest::qWait(50);
+    QTRY_COMPARE(tester->repaints, 6);
+}
+
 void tst_QGraphicsItem::updateCachedItemAfterMove()
 {
     // A simple item that uses ItemCoordinateCache