Fixed touch event delivery in QGraphicsView.

When a touch event with a second touch pressed is delivered inside
graphicsview, we should combine it with the closest touch point even if the
item under the second touch is not direct ancestor or child of the first
touches' target item.

So adding a second touch inside the item's bounding rect will send a
TouchUpdate event to the item instead or starting a new touch event sequence.

Task-number: QT-3795
Reviewed-by: Bradley T. Hughes

2 files changed, 61 insertions, 7 deletions

diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index a98ce6f..a02f3ac 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -5740,16 +5740,11 @@ void QGraphicsScenePrivate::touchEventHandler(QTouchEvent *sceneTouchEvent)
             }
 
             if (sceneTouchEvent->deviceType() == QTouchEvent::TouchScreen) {
-                // on touch-screens, combine this touch point with the closest one we find if it
-                // is a a direct descendent or ancestor (
+                // on touch-screens, combine this touch point with the closest one we find
                 int closestTouchPointId = findClosestTouchPointId(touchPoint.scenePos());
                 QGraphicsItem *closestItem = itemForTouchPointId.value(closestTouchPointId);
-                if (!item
-                    || (closestItem
-                        && (item->isAncestorOf(closestItem)
-                            || closestItem->isAncestorOf(item)))) {
+                if (!item || (closestItem && cachedItemsUnderMouse.contains(closestItem)))
                     item = closestItem;
-                }
             }
             if (!item)
                 continue;
diff --git a/tests/auto/qtouchevent/tst_qtouchevent.cpp b/tests/auto/qtouchevent/tst_qtouchevent.cpp
index bb80fde..4219ef4 100644
--- a/tests/auto/qtouchevent/tst_qtouchevent.cpp
+++ b/tests/auto/qtouchevent/tst_qtouchevent.cpp
@@ -109,6 +109,7 @@ class tst_QTouchEventGraphicsItem : public QGraphicsItem
 public:
     QList<QTouchEvent::TouchPoint> touchBeginPoints, touchUpdatePoints, touchEndPoints;
     bool seenTouchBegin, seenTouchUpdate, seenTouchEnd;
+    int touchBeginCounter, touchUpdateCounter, touchEndCounter;
     bool acceptTouchBegin, acceptTouchUpdate, acceptTouchEnd;
     bool deleteInTouchBegin, deleteInTouchUpdate, deleteInTouchEnd;
     tst_QTouchEventGraphicsItem **weakpointer;
@@ -131,6 +132,7 @@ public:
         touchUpdatePoints.clear();
         touchEndPoints.clear();
         seenTouchBegin = seenTouchUpdate = seenTouchEnd = false;
+        touchBeginCounter = touchUpdateCounter = touchEndCounter = 0;
         acceptTouchBegin = acceptTouchUpdate = acceptTouchEnd = true;
         deleteInTouchBegin = deleteInTouchUpdate = deleteInTouchEnd = false;
     }
@@ -146,6 +148,7 @@ public:
             if (seenTouchUpdate) qWarning("TouchBegin: TouchUpdate cannot happen before TouchBegin");
             if (seenTouchEnd) qWarning("TouchBegin: TouchEnd cannot happen before TouchBegin");
             seenTouchBegin = !seenTouchBegin && !seenTouchUpdate && !seenTouchEnd;
+            ++touchBeginCounter;
             touchBeginPoints = static_cast<QTouchEvent *>(event)->touchPoints();
             event->setAccepted(acceptTouchBegin);
             if (deleteInTouchBegin)
@@ -155,6 +158,7 @@ public:
             if (!seenTouchBegin) qWarning("TouchUpdate: have not seen TouchBegin");
             if (seenTouchEnd) qWarning("TouchUpdate: TouchEnd cannot happen before TouchUpdate");
             seenTouchUpdate = seenTouchBegin && !seenTouchEnd;
+            ++touchUpdateCounter;
             touchUpdatePoints = static_cast<QTouchEvent *>(event)->touchPoints();
             event->setAccepted(acceptTouchUpdate);
             if (deleteInTouchUpdate)
@@ -164,6 +168,7 @@ public:
             if (!seenTouchBegin) qWarning("TouchEnd: have not seen TouchBegin");
             if (seenTouchEnd) qWarning("TouchEnd: already seen a TouchEnd");
             seenTouchEnd = seenTouchBegin && !seenTouchEnd;
+            ++touchEndCounter;
             touchEndPoints = static_cast<QTouchEvent *>(event)->touchPoints();
             event->setAccepted(acceptTouchEnd);
             if (deleteInTouchEnd)
@@ -194,6 +199,7 @@ private slots:
     void deleteInEventHandler();
     void deleteInRawEventTranslation();
     void crashInQGraphicsSceneAfterNotHandlingTouchBegin();
+    void touchBeginWithGraphicsWidget();
 };
 
 void tst_QTouchEvent::touchDisabledByDefault()
@@ -1334,6 +1340,59 @@ void tst_QTouchEvent::crashInQGraphicsSceneAfterNotHandlingTouchBegin()
     QTest::touchEvent(view.viewport()).release(0, view.mapFromScene(QPoint(10, 10)));
 }
 
+void tst_QTouchEvent::touchBeginWithGraphicsWidget()
+{
+    QGraphicsScene scene;
+    QGraphicsView view(&scene);
+    tst_QTouchEventGraphicsItem *root;
+    root = new tst_QTouchEventGraphicsItem;
+    root->setAcceptTouchEvents(true);
+    scene.addItem(root);
+
+    QGraphicsWidget *glassWidget = new QGraphicsWidget;
+    glassWidget->setMinimumSize(100, 100);
+    scene.addItem(glassWidget);
+
+    view.resize(200, 200);
+    view.show();
+    QTest::qWaitForWindowShown(&view);
+    view.fitInView(scene.sceneRect());
+
+    QTest::touchEvent()
+            .press(0, view.mapFromScene(root->mapToScene(3,3)), view.viewport());
+    QTest::touchEvent()
+            .stationary(0)
+            .press(1, view.mapFromScene(root->mapToScene(6,6)), view.viewport());
+    QTest::touchEvent()
+            .release(0, view.mapFromScene(root->mapToScene(3,3)), view.viewport())
+            .release(1, view.mapFromScene(root->mapToScene(6,6)), view.viewport());
+
+    QCOMPARE(root->touchBeginCounter, 1);
+    QCOMPARE(root->touchUpdateCounter, 1);
+    QCOMPARE(root->touchEndCounter, 1);
+    QCOMPARE(root->touchUpdatePoints.size(), 2);
+
+    root->reset();
+    glassWidget->setWindowFlags(Qt::Window); // make the glassWidget a panel
+
+    QTest::touchEvent()
+            .press(0, view.mapFromScene(root->mapToScene(3,3)), view.viewport());
+    QTest::touchEvent()
+            .stationary(0)
+            .press(1, view.mapFromScene(root->mapToScene(6,6)), view.viewport());
+    QTest::touchEvent()
+            .release(0, view.mapFromScene(root->mapToScene(3,3)), view.viewport())
+            .release(1, view.mapFromScene(root->mapToScene(6,6)), view.viewport());
+
+    QCOMPARE(root->touchBeginCounter, 0);
+    QCOMPARE(root->touchUpdateCounter, 0);
+    QCOMPARE(root->touchEndCounter, 0);
+
+
+    delete root;
+    delete glassWidget;
+}
+
 QTEST_MAIN(tst_QTouchEvent)
 
 #include "tst_qtouchevent.moc"