Merge branch '4.7' of scm.dev.nokia.troll.no:qt/oslo-staging-2 into 4.7

3 files changed, 135 insertions, 19 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index fc44a44..60cd020 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -2125,7 +2125,7 @@ void QGraphicsItem::setToolTip(const QString &toolTip)
 
     \snippet doc/src/snippets/code/src_gui_graphicsview_qgraphicsitem.cpp 2
 
-    If no cursor has been set, the parent's cursor is used.
+    If no cursor has been set, the cursor of the item beneath is used.
 
     \sa setCursor(), hasCursor(), unsetCursor(), QWidget::cursor,
     QApplication::overrideCursor()
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index e58b93c..a0015dc 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -4362,6 +4362,50 @@ static void _q_paintIntoCache(QPixmap *pix, QGraphicsItem *item, const QRegion &
     }
 }
 
+// Copied from qpaintengine_vg.cpp
+// Returns true for 90, 180, and 270 degree rotations.
+static inline bool transformIsSimple(const QTransform& transform)
+{
+    QTransform::TransformationType type = transform.type();
+    if (type == QTransform::TxNone || type == QTransform::TxTranslate) {
+        return true;
+    } else if (type == QTransform::TxScale) {
+        // Check for 0 and 180 degree rotations.
+        // (0 might happen after 4 rotations of 90 degrees).
+        qreal m11 = transform.m11();
+        qreal m12 = transform.m12();
+        qreal m21 = transform.m21();
+        qreal m22 = transform.m22();
+        if (m12 == 0.0f && m21 == 0.0f) {
+            if (m11 == 1.0f && m22 == 1.0f)
+                return true; // 0 degrees
+            else if (m11 == -1.0f && m22 == -1.0f)
+                return true; // 180 degrees.
+            if(m11 == 1.0f && m22 == -1.0f)
+                return true; // 0 degrees inverted y.
+            else if(m11 == -1.0f && m22 == 1.0f)
+                return true; // 180 degrees inverted y.
+        }
+    } else if (type == QTransform::TxRotate) {
+        // Check for 90, and 270 degree rotations.
+        qreal m11 = transform.m11();
+        qreal m12 = transform.m12();
+        qreal m21 = transform.m21();
+        qreal m22 = transform.m22();
+        if (m11 == 0.0f && m22 == 0.0f) {
+            if (m12 == 1.0f && m21 == -1.0f)
+                return true; // 90 degrees.
+            else if (m12 == -1.0f && m21 == 1.0f)
+                return true; // 270 degrees.
+            else if (m12 == -1.0f && m21 == -1.0f)
+                return true; // 90 degrees inverted y.
+            else if (m12 == 1.0f && m21 == 1.0f)
+                return true; // 270 degrees inverted y.
+        }
+    }
+    return false;
+}
+
 /*!
     \internal
 
@@ -4530,32 +4574,28 @@ void QGraphicsScenePrivate::drawItemHelper(QGraphicsItem *item, QPainter *painte
         if (invertable)
             diff *= painter->worldTransform();
         deviceData->lastTransform = painter->worldTransform();
-        if (!invertable
-            || diff.type() > QTransform::TxTranslate
-            || painter->worldTransform().type() > QTransform::TxScale) {
+        bool allowPartialCacheExposure = false;
+        bool simpleTransform = invertable && diff.type() <= QTransform::TxTranslate
+                               && transformIsSimple(painter->worldTransform());
+        if (!simpleTransform) {
             pixModified = true;
             itemCache->allExposed = true;
             itemCache->exposed.clear();
+            deviceData->cacheIndent = QPoint();
             pix = QPixmap();
+        } else {
+            allowPartialCacheExposure = deviceData->cacheIndent != QPoint();
         }
 
-        // ### This is a pretty bad way to determine when to start partial
-        // exposure for DeviceCoordinateCache but it's the least intrusive
-        // approach for now.
-#if 0
-        // Only if the device rect isn't fully contained.
-        bool allowPartialCacheExposure = !viewRect.contains(deviceRect);
-#else
-        // Only if deviceRect is 20% taller or wider than the desktop.
-        bool allowPartialCacheExposure = false;
-        if (widget) {
-            QRect desktopRect = QApplication::desktop()->availableGeometry(widget);
-            allowPartialCacheExposure = (desktopRect.width() * 1.2 < deviceRect.width()
-                                         || desktopRect.height() * 1.2 < deviceRect.height());
+        // Allow partial cache exposure if the device rect isn't fully contained and
+        // deviceRect is 20% taller or wider than the viewRect.
+        if (!allowPartialCacheExposure && !viewRect.contains(deviceRect)) {
+            allowPartialCacheExposure = (viewRect.width() * 1.2 < deviceRect.width())
+                                         || (viewRect.height() * 1.2 < deviceRect.height());
         }
-#endif
+
         QRegion scrollExposure;
-        if (deviceData->cacheIndent != QPoint() || allowPartialCacheExposure) {
+        if (allowPartialCacheExposure) {
             // Part of pixmap is drawn. Either device contains viewrect (big
             // item covers whole screen) or parts of device are outside the
             // viewport. In either case the device rect must be the intersect
diff --git a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
index 25ec040..2901dd5 100644
--- a/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
+++ b/tests/auto/qgraphicsitem/tst_qgraphicsitem.cpp
@@ -445,6 +445,7 @@ private slots:
     void textItem_shortcuts();
     void scroll();
     void stopClickFocusPropagation();
+    void deviceCoordinateCache_simpleRotations();
 
     // task specific tests below me
     void task141694_textItemEnsureVisible();
@@ -10560,6 +10561,81 @@ void tst_QGraphicsItem::stopClickFocusPropagation()
     QVERIFY(itemWithFocus->hasFocus());
 }
 
+void tst_QGraphicsItem::deviceCoordinateCache_simpleRotations()
+{
+    // Make sure we don't invalidate the cache when applying simple
+    // (90, 180, 270, 360) rotation transforms to the item.
+    QGraphicsRectItem *item = new QGraphicsRectItem(0, 0, 300, 200);
+    item->setBrush(Qt::red);
+    item->setCacheMode(QGraphicsItem::DeviceCoordinateCache);
+
+    QGraphicsScene scene;
+    scene.setSceneRect(0, 0, 300, 200);
+    scene.addItem(item);
+
+    MyGraphicsView view(&scene);
+    view.show();
+    QTest::qWaitForWindowShown(&view);
+    QTRY_VERIFY(view.repaints > 0);
+
+    QGraphicsItemCache *itemCache = QGraphicsItemPrivate::get(item)->extraItemCache();
+    Q_ASSERT(itemCache);
+    QPixmapCache::Key currentKey = itemCache->deviceData.value(view.viewport()).key;
+
+    // Trigger an update and verify that the cache is unchanged.
+    QPixmapCache::Key oldKey = currentKey;
+    view.reset();
+    view.viewport()->update();
+    QTRY_VERIFY(view.repaints > 0);
+    currentKey = itemCache->deviceData.value(view.viewport()).key;
+    QCOMPARE(currentKey, oldKey);
+
+    // Check 90, 180, 270 and 360 degree rotations.
+    for (int angle = 90; angle <= 360; angle += 90) {
+        // Rotate item and verify that the cache was invalidated.
+        oldKey = currentKey;
+        view.reset();
+        QTransform transform;
+        transform.translate(150, 100);
+        transform.rotate(angle);
+        transform.translate(-150, -100);
+        item->setTransform(transform);
+        QTRY_VERIFY(view.repaints > 0);
+        currentKey = itemCache->deviceData.value(view.viewport()).key;
+        QVERIFY(currentKey != oldKey);
+
+        // IMPORTANT PART:
+        // Trigger an update and verify that the cache is unchanged.
+        oldKey = currentKey;
+        view.reset();
+        view.viewport()->update();
+        QTRY_VERIFY(view.repaints > 0);
+        currentKey = itemCache->deviceData.value(view.viewport()).key;
+        QCOMPARE(currentKey, oldKey);
+    }
+
+    // 45 degree rotation.
+    oldKey = currentKey;
+    view.reset();
+    QTransform transform;
+    transform.translate(150, 100);
+    transform.rotate(45);
+    transform.translate(-150, -100);
+    item->setTransform(transform);
+    QTRY_VERIFY(view.repaints > 0);
+    currentKey = itemCache->deviceData.value(view.viewport()).key;
+    QVERIFY(currentKey != oldKey);
+
+    // Trigger an update and verify that the cache was invalidated.
+    // We should always invalidate the cache for non-trivial transforms.
+    oldKey = currentKey;
+    view.reset();
+    view.viewport()->update();
+    QTRY_VERIFY(view.repaints > 0);
+    currentKey = itemCache->deviceData.value(view.viewport()).key;
+    QVERIFY(currentKey != oldKey);
+}
+
 void tst_QGraphicsItem::QTBUG_5418_textItemSetDefaultColor()
 {
     struct Item : public QGraphicsTextItem