QQuickWindow: obey AA_SynthesizeMouseForUnhandledTouchEvents

Until now, AA_SynthesizeMouseForUnhandledTouchEvents has only affected
behavior of QGuiApplicationPrivate::processTouchEvent, but had no
effect in Qt Quick.  QQuickWindow also accepts the touch event
just to make sure that QGuiApplication will not synthesize mouse
from touch, because it would be redundant: QQuickWindow does that
for itself.

Now we make it have an effect in Qt Quick too: skip mouse synthesis
if it is set to false.  This provides a way to simplify the
event delivery.  If you set it false, then you cannot manipulate old
mouse-only items like MouseArea and Flickable on a touchscreen.
(You can of course use event handlers for that.)

[ChangeLog][QtQuick][QQuickWindow] You can now disable touch->mouse
event synthesis in QtQuick by calling
qGuiApp.setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, false);
This will simplify and speed up event delivery, and it will also prevent
any and all interaction with mouse-only items like MouseArea and
Flickable on a touchscreen.

Task-number: QTBUG-52748
Change-Id: I71f1731b5abaeabd9dbce1112cd23bc97d24c12a
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>

5 files changed, 92 insertions, 63 deletions

diff --git a/tests/auto/quick/pointerhandlers/flickableinterop/tst_flickableinterop.cpp b/tests/auto/quick/pointerhandlers/flickableinterop/tst_flickableinterop.cpp
index 2d8b16cadd..e544eedf05 100644
--- a/tests/auto/quick/pointerhandlers/flickableinterop/tst_flickableinterop.cpp
+++ b/tests/auto/quick/pointerhandlers/flickableinterop/tst_flickableinterop.cpp
@@ -57,8 +57,6 @@ public:
     {}
 
 private slots:
-    void initTestCase();
-
     void touchTapButton_data();
     void touchTapButton();
     void touchDragFlickableBehindButton_data();
@@ -96,14 +94,6 @@ void tst_FlickableInterop::createView(QScopedPointer<QQuickView> &window, const
     QVERIFY(window->rootObject() != nullptr);
 }
 
-void tst_FlickableInterop::initTestCase()
-{
-    // This test assumes that we don't get synthesized mouse events from QGuiApplication
-    qApp->setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, false);
-
-    QQmlDataTest::initTestCase();
-}
-
 void tst_FlickableInterop::touchTapButton_data()
 {
     QTest::addColumn<QString>("buttonName");
diff --git a/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp b/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
index 0158d864c4..2a9ec272fa 100644
--- a/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
+++ b/tests/auto/quick/pointerhandlers/qquickpointerhandler/tst_qquickpointerhandler.cpp
@@ -223,6 +223,7 @@ public:
 private slots:
     void initTestCase();
 
+    void touchEventDelivery_data();
     void touchEventDelivery();
     void mouseEventDelivery();
     void touchReleaseOutside_data();
@@ -274,16 +275,23 @@ void tst_PointerHandlers::createView(QScopedPointer<QQuickView> &window, const c
 
 void tst_PointerHandlers::initTestCase()
 {
-    // This test assumes that we don't get synthesized mouse events from QGuiApplication
-    qApp->setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, false);
-
     QQmlDataTest::initTestCase();
     qmlRegisterType<EventItem>("Qt.test", 1, 0, "EventItem");
     qmlRegisterType<EventHandler>("Qt.test", 1, 0, "EventHandler");
 }
 
+void tst_PointerHandlers::touchEventDelivery_data()
+{
+    QTest::addColumn<bool>("synthMouse"); // AA_SynthesizeMouseForUnhandledTouchEvents
+    QTest::newRow("no synth") << false;
+    QTest::newRow("synth") << true;
+}
+
 void tst_PointerHandlers::touchEventDelivery()
 {
+    QFETCH(bool, synthMouse);
+    qApp->setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, synthMouse);
+
     QScopedPointer<QQuickView> windowPtr;
     createView(windowPtr, "singleitem.qml");
     QQuickView * window = windowPtr.data();
@@ -295,19 +303,20 @@ void tst_PointerHandlers::touchEventDelivery()
     QPoint p1 = QPoint(20, 20);
     QTest::touchEvent(window, touchDevice).press(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QTRY_COMPARE(eventItem1->eventList.size(), 3);
+    QTRY_COMPARE(eventItem1->eventList.size(), synthMouse ? 3 : 2);
     QCOMPARE_EVENT(0, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointPressed, NoGrab);
     QCOMPARE_EVENT(1, Event::TouchDestination, QEvent::TouchBegin, Qt::TouchPointPressed, NoGrab);
-    QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, NoGrab);
+    if (synthMouse)
+        QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, NoGrab);
     p1 += QPoint(10, 0);
     QTest::touchEvent(window, touchDevice).move(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 4);
-    QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, NoGrab);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 4 : 3);
+    QCOMPARE_EVENT(eventItem1->eventList.size() - 1, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, NoGrab);
     QTest::touchEvent(window, touchDevice).release(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 5);
-    QCOMPARE_EVENT(4, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, NoGrab);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 5 : 4);
+    QCOMPARE_EVENT(eventItem1->eventList.size() - 1, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, NoGrab);
     eventItem1->eventList.clear();
 
     // Accept touch
@@ -343,33 +352,42 @@ void tst_PointerHandlers::touchEventDelivery()
     p1 = QPoint(20, 20);
     QTest::touchEvent(window, touchDevice).press(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 3);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 3 : 2);
     QCOMPARE_EVENT(0, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointPressed, NoGrab);
     QCOMPARE_EVENT(1, Event::TouchDestination, QEvent::TouchBegin, Qt::TouchPointPressed, NoGrab);
-    QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, QQuickEventPoint::GrabExclusive);
-    QCOMPARE(window->mouseGrabberItem(), eventItem1);
+    if (synthMouse)
+        QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, QQuickEventPoint::GrabExclusive);
+    QCOMPARE(window->mouseGrabberItem(), synthMouse ? eventItem1 : nullptr);
 
     QPointF localPos = eventItem1->mapFromScene(p1);
     QPointF scenePos = p1; // item is at 0,0
     QCOMPARE(eventItem1->eventList.at(1).posWrtItem, localPos);
     QCOMPARE(eventItem1->eventList.at(1).posWrtScene, scenePos);
-    QCOMPARE(eventItem1->eventList.at(2).posWrtItem, localPos);
-    QCOMPARE(eventItem1->eventList.at(2).posWrtScene, scenePos);
+    if (synthMouse) {
+        QCOMPARE(eventItem1->eventList.at(2).posWrtItem, localPos);
+        QCOMPARE(eventItem1->eventList.at(2).posWrtScene, scenePos);
+    }
 
     p1 += QPoint(10, 0);
     QTest::touchEvent(window, touchDevice).move(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 6);
-    QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, NoGrab);
-    QCOMPARE_EVENT(4, Event::TouchDestination, QEvent::TouchUpdate, Qt::TouchPointMoved, NoGrab);
-    QCOMPARE_EVENT(5, Event::MouseDestination, QEvent::MouseMove, Qt::TouchPointMoved, QQuickEventPoint::GrabExclusive);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 6 : 3);
+    if (synthMouse) {
+        QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointMoved, NoGrab);
+        QCOMPARE_EVENT(4, Event::TouchDestination, QEvent::TouchUpdate, Qt::TouchPointMoved, NoGrab);
+        QCOMPARE_EVENT(5, Event::MouseDestination, QEvent::MouseMove, Qt::TouchPointMoved, QQuickEventPoint::GrabExclusive);
+    }
     QTest::touchEvent(window, touchDevice).release(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 10);
-    QCOMPARE_EVENT(6, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, NoGrab);
-    QCOMPARE_EVENT(7, Event::TouchDestination, QEvent::TouchEnd, Qt::TouchPointReleased, NoGrab);
-    QCOMPARE_EVENT(8, Event::MouseDestination, QEvent::MouseButtonRelease, Qt::TouchPointReleased, NoGrab);
-    QCOMPARE_EVENT(9, Event::MouseDestination, QEvent::UngrabMouse, Qt::TouchPointReleased, QQuickEventPoint::UngrabExclusive);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 10 : 4);
+    if (synthMouse) {
+        QCOMPARE_EVENT(6, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, NoGrab);
+        QCOMPARE_EVENT(7, Event::TouchDestination, QEvent::TouchEnd, Qt::TouchPointReleased, NoGrab);
+        QCOMPARE_EVENT(8, Event::MouseDestination, QEvent::MouseButtonRelease, Qt::TouchPointReleased, NoGrab);
+        QCOMPARE_EVENT(9, Event::MouseDestination, QEvent::UngrabMouse, Qt::TouchPointReleased, QQuickEventPoint::UngrabExclusive);
+    } else {
+        QCOMPARE_EVENT(3, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointReleased, NoGrab);
+    }
     eventItem1->eventList.clear();
 
     // wait to avoid getting a double click event
@@ -382,18 +400,19 @@ void tst_PointerHandlers::touchEventDelivery()
     p1 = QPoint(20, 20);
     QTest::touchEvent(window, touchDevice).press(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 3);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 3 : 2);
     QCOMPARE_EVENT(0, Event::HandlerDestination, QEvent::Pointer, Qt::TouchPointPressed, NoGrab);
     QCOMPARE_EVENT(1, Event::TouchDestination, QEvent::TouchBegin, Qt::TouchPointPressed, NoGrab);
-    QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, NoGrab);
+    if (synthMouse)
+        QCOMPARE_EVENT(2, Event::MouseDestination, QEvent::MouseButtonPress, Qt::TouchPointPressed, NoGrab);
     QCOMPARE(pointerEvent->point(0)->exclusiveGrabber(), nullptr);
     p1 += QPoint(10, 0);
     QTest::touchEvent(window, touchDevice).move(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 4);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 4 : 3);
     QTest::touchEvent(window, touchDevice).release(0, p1, window);
     QQuickTouchUtils::flush(window);
-    QCOMPARE(eventItem1->eventList.size(), 5);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 5 : 4);
     eventItem1->eventList.clear();
 
     // wait to avoid getting a double click event
diff --git a/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp b/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
index e0f1207ebe..578ae56cca 100644
--- a/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
+++ b/tests/auto/quick/qquickwindow/tst_qquickwindow.cpp
@@ -1234,8 +1234,8 @@ void tst_qquickwindow::synthMouseFromTouch()
     QTest::touchEvent(window.data(), touchDevice).move(0, p2, window.data());
     QTest::touchEvent(window.data(), touchDevice).release(0, p2, window.data());
 
-    QCOMPARE(item->m_touchEvents.count(), 3);
-    QCOMPARE(item->m_mouseEvents.count(), acceptTouch ? 0 : 3);
+    QCOMPARE(item->m_touchEvents.count(), !synthMouse && !acceptTouch ? 1 : 3);
+    QCOMPARE(item->m_mouseEvents.count(), (acceptTouch || !synthMouse) ? 0 : 3);
     QCOMPARE(window->m_mouseEvents.count(), 0);
     for (const QMouseEvent &ev : item->m_mouseEvents)
         QCOMPARE(ev.source(), Qt::MouseEventSynthesizedByQt);
diff --git a/tests/auto/quick/touchmouse/tst_touchmouse.cpp b/tests/auto/quick/touchmouse/tst_touchmouse.cpp
index 2fc56c2ad8..052d81b6de 100644
--- a/tests/auto/quick/touchmouse/tst_touchmouse.cpp
+++ b/tests/auto/quick/touchmouse/tst_touchmouse.cpp
@@ -176,6 +176,7 @@ public:
 private slots:
     void initTestCase();
 
+    void simpleTouchEvent_data();
     void simpleTouchEvent();
     void testEventFilter();
     void mouse();
@@ -226,15 +227,22 @@ QQuickView *tst_TouchMouse::createView()
 
 void tst_TouchMouse::initTestCase()
 {
-    // This test assumes that we don't get synthesized mouse events from QGuiApplication
-    qApp->setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, false);
-
     QQmlDataTest::initTestCase();
     qmlRegisterType<EventItem>("Qt.test", 1, 0, "EventItem");
 }
 
+void tst_TouchMouse::simpleTouchEvent_data()
+{
+    QTest::addColumn<bool>("synthMouse"); // AA_SynthesizeMouseForUnhandledTouchEvents
+    QTest::newRow("no synth") << false;
+    QTest::newRow("synth") << true;
+}
+
 void tst_TouchMouse::simpleTouchEvent()
 {
+    QFETCH(bool, synthMouse);
+    qApp->setAttribute(Qt::AA_SynthesizeMouseForUnhandledTouchEvents, synthMouse);
+
     QScopedPointer<QQuickView> window(createView());
     window->setSource(testFileUrl("singleitem.qml"));
     window->show();
@@ -251,16 +259,16 @@ void tst_TouchMouse::simpleTouchEvent()
     QTest::touchEvent(window.data(), device).press(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
     // Get a touch and then mouse event offered
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     QCOMPARE(eventItem1->eventList.at(0).type, QEvent::TouchBegin);
     p1 += QPoint(10, 0);
     QTest::touchEvent(window.data(), device).move(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
     // Not accepted, no updates
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     QTest::touchEvent(window.data(), device).release(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     eventItem1->eventList.clear();
 
     // Accept touch
@@ -288,10 +296,11 @@ void tst_TouchMouse::simpleTouchEvent()
     p1 = QPoint(20, 20);
     QTest::touchEvent(window.data(), device).press(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     QCOMPARE(eventItem1->eventList.at(0).type, QEvent::TouchBegin);
-    QCOMPARE(eventItem1->eventList.at(1).type, QEvent::MouseButtonPress);
-    QCOMPARE(window->mouseGrabberItem(), eventItem1);
+    if (synthMouse)
+        QCOMPARE(eventItem1->eventList.at(1).type, QEvent::MouseButtonPress);
+    QCOMPARE(window->mouseGrabberItem(), synthMouse ? eventItem1 : nullptr);
 
     QPoint localPos = eventItem1->mapFromScene(p1).toPoint();
     QPoint globalPos = window->mapToGlobal(p1);
@@ -299,21 +308,31 @@ void tst_TouchMouse::simpleTouchEvent()
     QCOMPARE(eventItem1->eventList.at(0).points.at(0).pos().toPoint(), localPos);
     QCOMPARE(eventItem1->eventList.at(0).points.at(0).scenePos().toPoint(), scenePos);
     QCOMPARE(eventItem1->eventList.at(0).points.at(0).screenPos().toPoint(), globalPos);
-    QCOMPARE(eventItem1->eventList.at(1).mousePos, localPos);
-    QCOMPARE(eventItem1->eventList.at(1).mousePosGlobal, globalPos);
+    if (synthMouse) {
+        QCOMPARE(eventItem1->eventList.at(1).mousePos, localPos);
+        QCOMPARE(eventItem1->eventList.at(1).mousePosGlobal, globalPos);
+    }
 
     p1 += QPoint(10, 0);
     QTest::touchEvent(window.data(), device).move(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 4);
-    QCOMPARE(eventItem1->eventList.at(2).type, QEvent::TouchUpdate);
-    QCOMPARE(eventItem1->eventList.at(3).type, QEvent::MouseMove);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 4 : 1);
+    if (synthMouse) {
+        QCOMPARE(eventItem1->eventList.at(2).type, QEvent::TouchUpdate);
+        QCOMPARE(eventItem1->eventList.at(3).type, QEvent::MouseMove);
+    }
+    // else, if there was no synth-mouse and we didn't accept the touch,
+    // TouchUpdate was not sent to eventItem1 either.
     QTest::touchEvent(window.data(), device).release(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 7);
-    QCOMPARE(eventItem1->eventList.at(4).type, QEvent::TouchEnd);
-    QCOMPARE(eventItem1->eventList.at(5).type, QEvent::MouseButtonRelease);
-    QCOMPARE(eventItem1->eventList.at(6).type, QEvent::UngrabMouse);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 7 : 1);
+    if (synthMouse) {
+        QCOMPARE(eventItem1->eventList.at(4).type, QEvent::TouchEnd);
+        QCOMPARE(eventItem1->eventList.at(5).type, QEvent::MouseButtonRelease);
+        QCOMPARE(eventItem1->eventList.at(6).type, QEvent::UngrabMouse);
+    }
+    // else, if there was no synth-mouse and we didn't accept the touch,
+    // TouchEnd was not sent to eventItem1 either.
     eventItem1->eventList.clear();
 
     // wait to avoid getting a double click event
@@ -326,16 +345,17 @@ void tst_TouchMouse::simpleTouchEvent()
     p1 = QPoint(20, 20);
     QTest::touchEvent(window.data(), device).press(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     QCOMPARE(eventItem1->eventList.at(0).type, QEvent::TouchBegin);
-    QCOMPARE(eventItem1->eventList.at(1).type, QEvent::MouseButtonPress);
+    if (synthMouse)
+        QCOMPARE(eventItem1->eventList.at(1).type, QEvent::MouseButtonPress);
     p1 += QPoint(10, 0);
     QTest::touchEvent(window.data(), device).move(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     QTest::touchEvent(window.data(), device).release(0, p1, window.data());
     QQuickTouchUtils::flush(window.data());
-    QCOMPARE(eventItem1->eventList.size(), 2);
+    QCOMPARE(eventItem1->eventList.size(), synthMouse ? 2 : 1);
     eventItem1->eventList.clear();
 
     // wait to avoid getting a double click event
diff --git a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
index af358925fe..e523274d0a 100644
--- a/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
+++ b/tests/auto/quickwidgets/qquickwidget/tst_qquickwidget.cpp
@@ -614,8 +614,8 @@ void tst_qquickwidget::synthMouseFromTouch()
     QTest::touchEvent(&window, device).move(0, p2, &window);
     QTest::touchEvent(&window, device).release(0, p2, &window);
 
-    QCOMPARE(item->m_touchEvents.count(), 3);
-    QCOMPARE(item->m_mouseEvents.count(), acceptTouch ? 0 : 3);
+    QCOMPARE(item->m_touchEvents.count(), !synthMouse && !acceptTouch ? 1 : 3);
+    QCOMPARE(item->m_mouseEvents.count(), (acceptTouch || !synthMouse) ? 0 : 3);
     QCOMPARE(childView->m_mouseEvents.count(), 0);
     for (const QMouseEvent &ev : item->m_mouseEvents)
         QCOMPARE(ev.source(), Qt::MouseEventSynthesizedByQt);