Do not stop delivering to handlers if all points are accepted

Some Pointer Handlers can perform the desired interaction using only
passive grabs.  When such a handler is used to modify behavior of
another event-handling Item or Handler which needs to take the
exclusive grab, this allows them to cooperate: both can see the
updates, and neither prevents delivery of events to both.

Change-Id: I312cc301c52fcdf805245bbe0ac60fd28f92c01f
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

5 files changed, 212 insertions, 16 deletions

diff --git a/src/quick/items/qquickwindow.cpp b/src/quick/items/qquickwindow.cpp
index 2d0f1218bf..8582dd8d2c 100644
--- a/src/quick/items/qquickwindow.cpp
+++ b/src/quick/items/qquickwindow.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQuick module of the Qt Toolkit.
@@ -2422,8 +2422,6 @@ void QQuickWindowPrivate::deliverUpdatedTouchPoints(QQuickPointerTouchEvent *eve
                 done = true;
             event->localize(receiver);
             handler->handlePointerEvent(event);
-            if (event->allPointsAccepted())
-                done = true;
         }
         if (done)
             break;
@@ -2524,8 +2522,6 @@ void QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
     }
     if (handlersOnly)
         return;
-    if (pointerEvent->allPointsAccepted() && !pointerEvent->isReleaseEvent())
-        return;
 
     // If all points are released and the item is not the grabber, it doesn't get the event.
     // But if at least one point is still pressed, we might be in a potential gesture-takeover scenario.
@@ -2537,8 +2533,6 @@ void QQuickWindowPrivate::deliverMatchingPointsToItem(QQuickItem *item, QQuickPo
     auto event = pointerEvent->asPointerMouseEvent();
     if (event && item->acceptedMouseButtons() & event->button()) {
             auto point = event->point(0);
-            if (point->isAccepted())
-                return;
             // The only reason to already have a mouse grabber here is
             // synthetic events - flickable sends one when setPressDelay is used.
             auto oldMouseGrabber = q->mouseGrabberItem();
diff --git a/tests/auto/quick/pointerhandlers/qquickdraghandler/data/simpleTapAndDragHandlers.qml b/tests/auto/quick/pointerhandlers/qquickdraghandler/data/simpleTapAndDragHandlers.qml
new file mode 100644
index 0000000000..adb8332213
--- /dev/null
+++ b/tests/auto/quick/pointerhandlers/qquickdraghandler/data/simpleTapAndDragHandlers.qml
@@ -0,0 +1,112 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the manual tests of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:GPL-EXCEPT$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.8
+import Qt.labs.handlers 1.0
+
+Rectangle {
+    id: root
+    width: 900
+    height: 850
+    objectName: "root"
+    color: "#222222"
+
+    Row {
+        objectName: "row"
+        anchors.fill: parent
+        spacing: 10
+        Rectangle {
+            width: 50
+            height: 50
+            color: "aqua"
+            objectName: "dragAndTap"
+            DragHandler {
+                objectName: "drag"
+            }
+            TapHandler {
+                objectName: "tap"
+                gesturePolicy: TapHandler.DragThreshold
+            }
+        }
+        Rectangle {
+            width: 50
+            height: 50
+            color: "aqua"
+            objectName: "tapAndDrag"
+            TapHandler {
+                objectName: "tap"
+                gesturePolicy: TapHandler.DragThreshold
+            }
+            DragHandler {
+                objectName: "drag"
+            }
+        }
+
+        Rectangle {
+            color: "aqua"
+            width: 50
+            height: 50
+            objectName: "dragAndTapNotSiblings"
+            DragHandler {
+                objectName: "drag"
+            }
+            Rectangle {
+                color: "blue"
+                width: 30
+                height: 30
+                anchors.centerIn: parent
+                TapHandler {
+                    objectName: "tap"
+                    gesturePolicy: TapHandler.DragThreshold
+                }
+            }
+        }
+        Rectangle {
+            color: "aqua"
+            width: 50
+            height: 50
+            objectName: "tapAndDragNotSiblings"
+            TapHandler {
+                objectName: "tap"
+                gesturePolicy: TapHandler.DragThreshold
+            }
+            Rectangle {
+                color: "blue"
+                x: 10
+                y: 10
+                width: 30
+                height: 30
+                DragHandler {
+                    objectName: "drag"
+                }
+            }
+        }
+
+
+    }
+}
diff --git a/tests/auto/quick/pointerhandlers/qquickdraghandler/qquickdraghandler.pro b/tests/auto/quick/pointerhandlers/qquickdraghandler/qquickdraghandler.pro
index b50fe5ca6f..42c4e46c4f 100644
--- a/tests/auto/quick/pointerhandlers/qquickdraghandler/qquickdraghandler.pro
+++ b/tests/auto/quick/pointerhandlers/qquickdraghandler/qquickdraghandler.pro
@@ -12,4 +12,10 @@ include (../../shared/util.pri)
 
 TESTDATA = data/*
 
-# OTHER_FILES += data/foo.qml
+OTHER_FILES += data/DragAnywhereSlider.qml \
+    data/FlashAnimation.qml \
+    data/Slider.qml \
+    data/draggables.qml \
+    data/grabberstate.qml \
+    data/multipleSliders.qml \
+    data/reparenting.qml \
diff --git a/tests/auto/quick/pointerhandlers/qquickdraghandler/tst_qquickdraghandler.cpp b/tests/auto/quick/pointerhandlers/qquickdraghandler/tst_qquickdraghandler.cpp
index 8dc035949e..f827b82205 100644
--- a/tests/auto/quick/pointerhandlers/qquickdraghandler/tst_qquickdraghandler.cpp
+++ b/tests/auto/quick/pointerhandlers/qquickdraghandler/tst_qquickdraghandler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -58,9 +58,12 @@ private slots:
     void touchDragMulti();
     void touchDragMultiSliders_data();
     void touchDragMultiSliders();
+    void touchPassiveGrabbers_data();
+    void touchPassiveGrabbers();
 
 private:
     void createView(QScopedPointer<QQuickView> &window, const char *fileName);
+    QSet<QQuickPointerHandler *> passiveGrabbers(QQuickWindow *window, int pointId = 0);
     QTouchDevice *touchDevice;
 };
 
@@ -77,6 +80,24 @@ void tst_DragHandler::createView(QScopedPointer<QQuickView> &window, const char
     QVERIFY(window->rootObject() != 0);
 }
 
+QSet<QQuickPointerHandler*> tst_DragHandler::passiveGrabbers(QQuickWindow *window, int pointId /*= 0*/)
+{
+    QSet<QQuickPointerHandler*> result;
+    QQuickWindowPrivate *winp = QQuickWindowPrivate::get(window);
+    if (QQuickPointerDevice* device = QQuickPointerDevice::touchDevice(touchDevice)) {
+        QQuickPointerEvent *pointerEvent = winp->pointerEventInstance(device);
+        for (int i = 0; i < pointerEvent->pointCount(); ++i) {
+            QQuickEventPoint *eventPoint = pointerEvent->point(i);
+            QVector<QPointer <QQuickPointerHandler> > passives = eventPoint->passiveGrabbers();
+            if (!pointId || eventPoint->pointId() == pointId) {
+                for (auto it = passives.constBegin(); it != passives.constEnd(); ++it)
+                    result << it->data();
+            }
+        }
+    }
+    return result;
+}
+
 void tst_DragHandler::initTestCase()
 {
     // This test assumes that we don't get synthesized mouse events from QGuiApplication
@@ -398,6 +419,68 @@ void tst_DragHandler::touchDragMultiSliders()
     touch.commit();
 }
 
+void tst_DragHandler::touchPassiveGrabbers_data()
+{
+    QTest::addColumn<QString>("itemName");
+    QTest::addColumn<QStringList>("expectedPassiveGrabberNames");
+
+    QTest::newRow("Drag And Tap") << "dragAndTap" << QStringList({"drag", "tap"});
+    QTest::newRow("Tap And Drag") << "tapAndDrag" << QStringList({"tap", "drag"});
+    QTest::newRow("Drag And Tap (not siblings)") << "dragAndTapNotSiblings" << QStringList({"drag", "tap"});
+    QTest::newRow("Tap And Drag (not siblings)") << "tapAndDragNotSiblings" << QStringList({"tap", "drag"});
+}
+
+void tst_DragHandler::touchPassiveGrabbers()
+{
+    QFETCH(QString, itemName);
+    QFETCH(QStringList, expectedPassiveGrabberNames);
+
+    QScopedPointer<QQuickView> windowPtr;
+    createView(windowPtr, "simpleTapAndDragHandlers.qml");
+    QQuickView * window = windowPtr.data();
+
+    QQuickItem *row2 = window->rootObject()->findChild<QQuickItem*>(itemName);
+    QSet<QQuickPointerHandler *> expectedPassiveGrabbers;
+    for (QString objectName : expectedPassiveGrabberNames)
+        expectedPassiveGrabbers << row2->findChild<QQuickPointerHandler*>(objectName);
+
+    QPointF p1 = row2->mapToScene(row2->clipRect().center());
+    QTest::QTouchEventSequence touch = QTest::touchEvent(window, touchDevice);
+    touch.press(1, p1.toPoint()).commit();
+    QQuickTouchUtils::flush(window);
+
+    QCOMPARE(passiveGrabbers(window), expectedPassiveGrabbers);
+
+    QQuickDragHandler *dragHandler = nullptr;
+    for (QQuickPointerHandler *handler: expectedPassiveGrabbers) {
+        QCOMPARE(static_cast<QQuickSinglePointHandler *>(handler)->point().scenePressPosition(), p1);
+        QQuickDragHandler *dh = qmlobject_cast<QQuickDragHandler *>(handler);
+        if (dh)
+            dragHandler = dh;
+    }
+    QVERIFY(dragHandler);
+    QPointF initialPos = dragHandler->target()->position();
+
+    p1 += QPointF(50, 50);
+    touch.move(1, p1.toPoint()).commit();
+    QQuickTouchUtils::flush(window);
+    QTRY_VERIFY(dragHandler->active());
+
+    p1 += QPointF(50, 50);
+    touch.move(1, p1.toPoint()).commit();
+    QQuickTouchUtils::flush(window);
+    QPointF movementDelta = dragHandler->target()->position() - initialPos;
+    qCDebug(lcPointerTests) << "DragHandler moved the target by" << movementDelta;
+    QVERIFY(movementDelta.x() >= 100);
+    QVERIFY(movementDelta.y() >= 100);
+
+    QTest::qWait(500);
+
+    touch.release(1, p1.toPoint());
+    touch.commit();
+    QQuickTouchUtils::flush(window);
+}
+
 QTEST_MAIN(tst_DragHandler)
 
 #include "tst_qquickdraghandler.moc"
diff --git a/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp b/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
index cc39dd54f7..d38ae3190e 100644
--- a/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
+++ b/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
@@ -1,6 +1,6 @@
 /****************************************************************************
 **
-** Copyright (C) 2017 The Qt Company Ltd.
+** Copyright (C) 2018 The Qt Company Ltd.
 ** Contact: https://www.qt.io/licensing/
 **
 ** This file is part of the QtQml module of the Qt Toolkit.
@@ -504,17 +504,18 @@ void tst_PointerHandlers::mouseEventDelivery()
     eventItem1->grabPointer = true;
     p1 = QPoint(20, 20);
     QTest::mousePress(window, Qt::LeftButton, Qt::NoModifier, p1);
-    QTRY_COMPARE(eventItem1->eventList.size(), 2);
+    QTRY_COMPARE(eventItem1->eventList.size(), 3);
     QCOMPARE_EVENT(0, Event::HandlerDestination, QEvent::None, Qt::TouchPointPressed, QQuickEventPoint::GrabExclusive);
     QCOMPARE_EVENT(1, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointPressed, QQuickEventPoint::GrabExclusive);
+    QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, 0);
     p1 += QPoint(10, 0);
     QTest::mouseMove(window, p1);
-    QCOMPARE(eventItem1->eventList.size(), 3);
-    QCOMPARE_EVENT(2, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, QQuickEventPoint::GrabExclusive);
+    QCOMPARE(eventItem1->eventList.size(), 4);
+    QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, QQuickEventPoint::GrabExclusive);
     QTest::mouseRelease(window, Qt::LeftButton, Qt::NoModifier, p1);
-    QCOMPARE(eventItem1->eventList.size(), 5);
-    QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, QQuickEventPoint::GrabExclusive);
-    QCOMPARE_EVENT(4, Event::HandlerDestination, QEvent::None, Qt::TouchPointReleased, QQuickEventPoint::UngrabExclusive);
+    QCOMPARE(eventItem1->eventList.size(), 6);
+    QCOMPARE_EVENT(4, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, QQuickEventPoint::GrabExclusive);
+    QCOMPARE_EVENT(5, Event::HandlerDestination, QEvent::None, Qt::TouchPointReleased, QQuickEventPoint::UngrabExclusive);
     eventItem1->eventList.clear();
 }