MouseArea: react to touch ungrab

If an event handler (such as DragHandler) takes the exclusive grab
of a touchpoint that MouseArea had already grabbed as a synth-mouse,
it should react in the same way as if its grab of the actual mouse was
stolen: release the pressed state, etc.

Fixes: QTBUG-77624
Change-Id: I51f4fb253f7d0377be421c23e617942507616e72
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
(cherry picked from commit 23df1603f514407d245a2740f32f589318ef654e)

4 files changed, 234 insertions, 0 deletions

diff --git a/tests/auto/quick/pointerhandlers/mousearea_interop/data/dragTakeOverFromSibling.qml b/tests/auto/quick/pointerhandlers/mousearea_interop/data/dragTakeOverFromSibling.qml
new file mode 100644
index 0000000000..48b1dc86f0
--- /dev/null
+++ b/tests/auto/quick/pointerhandlers/mousearea_interop/data/dragTakeOverFromSibling.qml
@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the test suite 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 2.12
+
+Item {
+    width: 640
+    height: 480
+
+    Rectangle {
+        width: 200
+        height: 200
+        color: mouseArea.pressed ? "red" : "blue"
+        opacity: 0.6
+
+        MouseArea {
+            id: mouseArea
+            anchors.fill: parent
+        }
+    }
+    Rectangle {
+        y: 100
+        z: -1
+        width: 200
+        height: 200
+        color: dragHandler.active ? "orange" : "green"
+        opacity: 0.6
+
+        DragHandler {
+            id: dragHandler
+        }
+    }
+}
diff --git a/tests/auto/quick/pointerhandlers/mousearea_interop/mousearea_interop.pro b/tests/auto/quick/pointerhandlers/mousearea_interop/mousearea_interop.pro
new file mode 100644
index 0000000000..0bf0ec86a9
--- /dev/null
+++ b/tests/auto/quick/pointerhandlers/mousearea_interop/mousearea_interop.pro
@@ -0,0 +1,15 @@
+CONFIG += testcase
+
+TARGET = tst_mousearea_interop
+QT += core-private gui-private qml-private quick-private  testlib
+
+macos:CONFIG -= app_bundle
+
+SOURCES  += tst_mousearea_interop.cpp
+
+include (../../../shared/util.pri)
+include (../../shared/util.pri)
+
+TESTDATA = data/*
+
+OTHER_FILES += data/dragTakeOverFromSibling.qml
diff --git a/tests/auto/quick/pointerhandlers/mousearea_interop/tst_mousearea_interop.cpp b/tests/auto/quick/pointerhandlers/mousearea_interop/tst_mousearea_interop.cpp
new file mode 100644
index 0000000000..03cff92f46
--- /dev/null
+++ b/tests/auto/quick/pointerhandlers/mousearea_interop/tst_mousearea_interop.cpp
@@ -0,0 +1,160 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQml module 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtTest/QtTest>
+
+#include <QtQml/qqmlengine.h>
+#include <QtQml/qqmlproperty.h>
+#include <QtQuick/private/qquickdraghandler_p.h>
+#include <QtQuick/private/qquickmousearea_p.h>
+#include <QtQuick/qquickitem.h>
+#include <QtQuick/qquickview.h>
+
+#include "../../../shared/util.h"
+#include "../../shared/viewtestutil.h"
+
+Q_LOGGING_CATEGORY(lcPointerTests, "qt.quick.pointer.tests")
+
+class tst_MouseAreaInterop : public QQmlDataTest
+{
+    Q_OBJECT
+public:
+    tst_MouseAreaInterop()
+      : touchDevice(QTest::createTouchDevice())
+      , touchPointerDevice(QQuickPointerDevice::touchDevice(touchDevice))
+    {}
+
+private slots:
+    void dragHandlerInSiblingStealingGrabFromMouseAreaViaMouse();
+    void dragHandlerInSiblingStealingGrabFromMouseAreaViaTouch();
+
+private:
+    void createView(QScopedPointer<QQuickView> &window, const char *fileName);
+    QTouchDevice *touchDevice;
+    QQuickPointerDevice *touchPointerDevice;
+};
+
+void tst_MouseAreaInterop::createView(QScopedPointer<QQuickView> &window, const char *fileName)
+{
+    window.reset(new QQuickView);
+    window->setSource(testFileUrl(fileName));
+    QTRY_COMPARE(window->status(), QQuickView::Ready);
+    QQuickViewTestUtil::centerOnScreen(window.data());
+    QQuickViewTestUtil::moveMouseAway(window.data());
+
+    window->show();
+    QVERIFY(QTest::qWaitForWindowActive(window.data()));
+    QVERIFY(window->rootObject() != nullptr);
+}
+
+void tst_MouseAreaInterop::dragHandlerInSiblingStealingGrabFromMouseAreaViaMouse()
+{
+    const int dragThreshold = QGuiApplication::styleHints()->startDragDistance();
+    QScopedPointer<QQuickView> windowPtr;
+    createView(windowPtr, "dragTakeOverFromSibling.qml");
+    QQuickView * window = windowPtr.data();
+    auto pointerEvent = QQuickWindowPrivate::get(window)->pointerEventInstance(QQuickPointerDevice::genericMouseDevice());
+
+    QPointer<QQuickPointerHandler> handler = window->rootObject()->findChild<QQuickPointerHandler*>();
+    QVERIFY(handler);
+    QQuickMouseArea *ma = window->rootObject()->findChild<QQuickMouseArea*>();
+    QVERIFY(ma);
+
+    QPoint p1(150, 150);
+    QTest::mousePress(window, Qt::LeftButton, Qt::NoModifier, p1);
+    QCOMPARE(window->mouseGrabberItem(), ma);
+    QCOMPARE(ma->pressed(), true);
+
+    // Start dragging
+    // DragHandler keeps monitoring, due to its passive grab,
+    // and eventually steals the exclusive grab from MA
+    int dragStoleGrab = 0;
+    for (int i = 0; i < 4; ++i) {
+        p1 += QPoint(dragThreshold / 2, 0);
+        QTest::mouseMove(window, p1);
+        if (!dragStoleGrab && pointerEvent->point(0)->exclusiveGrabber() == handler)
+            dragStoleGrab = i;
+    }
+    if (dragStoleGrab)
+        qCDebug(lcPointerTests, "DragHandler stole the grab after %d events", dragStoleGrab);
+    QVERIFY(dragStoleGrab > 1);
+    QCOMPARE(handler->active(), true);
+    QCOMPARE(ma->pressed(), false);
+
+    QTest::mouseRelease(window, Qt::LeftButton, Qt::NoModifier, p1);
+    QCOMPARE(handler->active(), false);
+}
+
+void tst_MouseAreaInterop::dragHandlerInSiblingStealingGrabFromMouseAreaViaTouch() // QTBUG-77624
+{
+    const int dragThreshold = QGuiApplication::styleHints()->startDragDistance();
+    QScopedPointer<QQuickView> windowPtr;
+    createView(windowPtr, "dragTakeOverFromSibling.qml");
+    QQuickView * window = windowPtr.data();
+    auto pointerEvent = QQuickWindowPrivate::get(window)->pointerEventInstance(touchPointerDevice);
+
+    QPointer<QQuickPointerHandler> handler = window->rootObject()->findChild<QQuickPointerHandler*>();
+    QVERIFY(handler);
+    QQuickMouseArea *ma = window->rootObject()->findChild<QQuickMouseArea*>();
+    QVERIFY(ma);
+
+    QPoint p1(150, 150);
+    QTest::QTouchEventSequence touch = QTest::touchEvent(window, touchDevice);
+
+    touch.press(1, p1).commit();
+    QQuickTouchUtils::flush(window);
+    QTRY_VERIFY(pointerEvent->point(0)->passiveGrabbers().contains(handler));
+    QCOMPARE(pointerEvent->point(0)->grabberItem(), ma);
+    QCOMPARE(window->mouseGrabberItem(), ma);
+    QCOMPARE(ma->pressed(), true);
+
+    // Start dragging
+    // DragHandler keeps monitoring, due to its passive grab,
+    // and eventually steals the exclusive grab from MA
+    int dragStoleGrab = 0;
+    for (int i = 0; i < 4; ++i) {
+        p1 += QPoint(dragThreshold / 2, 0);
+        touch.move(1, p1).commit();
+        QQuickTouchUtils::flush(window);
+        if (!dragStoleGrab && pointerEvent->point(0)->exclusiveGrabber() == handler)
+            dragStoleGrab = i;
+    }
+    if (dragStoleGrab)
+        qCDebug(lcPointerTests, "DragHandler stole the grab after %d events", dragStoleGrab);
+    QVERIFY(dragStoleGrab > 1);
+    QCOMPARE(handler->active(), true);
+    QCOMPARE(ma->pressed(), false);
+
+    touch.release(1, p1).commit();
+    QQuickTouchUtils::flush(window);
+    QCOMPARE(handler->active(), false);
+}
+
+QTEST_MAIN(tst_MouseAreaInterop)
+
+#include "tst_mousearea_interop.moc"
diff --git a/tests/auto/quick/pointerhandlers/pointerhandlers.pro b/tests/auto/quick/pointerhandlers/pointerhandlers.pro
index 950d6835eb..ce616430e8 100644
--- a/tests/auto/quick/pointerhandlers/pointerhandlers.pro
+++ b/tests/auto/quick/pointerhandlers/pointerhandlers.pro
@@ -3,6 +3,7 @@ TEMPLATE = subdirs
 qtConfig(private_tests) {
     SUBDIRS += \
         flickableinterop \
+        mousearea_interop \
         multipointtoucharea_interop \
         qquickdraghandler \
         qquickhoverhandler \