Support masking of QQuickItems

Adding a new property, containsMask, to QQuickItem, that can be set
to any QObject defining a
Q_INVOKABLE bool contains(const QPointF &point).
When this property is set, the mask object contains method is used in
place of the item own contains method.

[ChangeLog][QtQuick][QQuickItem] Added containsMask property.

Task-number: QTBUG-20524
Change-Id: I5b0696e2cddc6ae3e217ce149c5f44980fdb69aa
Reviewed-by: Jan Arve Sæther <jan-arve.saether@qt.io>
Reviewed-by: Shawn Rutledge <shawn.rutledge@qt.io>

3 files changed, 127 insertions, 1 deletions

diff --git a/tests/auto/quick/qquickmousearea/data/mask.qml b/tests/auto/quick/qquickmousearea/data/mask.qml
new file mode 100644
index 0000000000..23e93f0310
--- /dev/null
+++ b/tests/auto/quick/qquickmousearea/data/mask.qml
@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 Ford Motor Company
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtQuick module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** 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-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.11
+import Test 1.0
+
+Item {
+    id: root
+    property int clicked: 0
+    property int pressed: 0
+    property int released: 0
+
+    width: 200; height: 200
+
+    MouseArea {
+        id: mouseArea
+        width: 200; height: 200
+        onPressed: { root.pressed++ }
+        onClicked: { root.clicked++ }
+        onReleased: { root.released++ }
+
+        containsMask: CircleMask {
+            radius: mouseArea.width/2
+        }
+    }
+}
+
diff --git a/tests/auto/quick/qquickmousearea/qquickmousearea.pro b/tests/auto/quick/qquickmousearea/qquickmousearea.pro
index 3a4dfa946f..ee9d6dce2b 100644
--- a/tests/auto/quick/qquickmousearea/qquickmousearea.pro
+++ b/tests/auto/quick/qquickmousearea/qquickmousearea.pro
@@ -6,6 +6,8 @@ HEADERS += ../../shared/testhttpserver.h
 SOURCES += tst_qquickmousearea.cpp \
            ../../shared/testhttpserver.cpp
 
+OTHER_FILES += $$files(data/*.qml)
+
 include (../../shared/util.pri)
 include (../shared/util.pri)
 
diff --git a/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp b/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
index b9a9dabf00..4fe01787fa 100644
--- a/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
+++ b/tests/auto/quick/qquickmousearea/tst_qquickmousearea.cpp
@@ -68,13 +68,45 @@ static bool initView(QQuickView &v, const QUrl &url, bool moveMouseOut, QByteArr
     return true;
 }
 
+class CircleMask : public QObject
+{
+    Q_OBJECT
+    Q_PROPERTY(qreal radius READ radius WRITE setRadius NOTIFY radiusChanged)
+
+public:
+    virtual ~CircleMask() {}
+    qreal radius() const { return m_radius; }
+    void setRadius(qreal radius)
+    {
+        if (m_radius == radius)
+            return;
+        m_radius = radius;
+        emit radiusChanged();
+    }
+
+    Q_INVOKABLE bool contains(const QPointF &point) const
+    {
+        QPointF center(m_radius, m_radius);
+        QLineF line(center, point);
+        return line.length() <= m_radius;
+    }
+
+signals:
+    void radiusChanged();
+
+private:
+    qreal m_radius;
+};
+
 class tst_QQuickMouseArea: public QQmlDataTest
 {
     Q_OBJECT
 public:
     tst_QQuickMouseArea()
         : device(nullptr)
-    {}
+    {
+        qmlRegisterType<CircleMask>("Test", 1, 0, "CircleMask");
+    }
 
 private slots:
     void initTestCase() override;
@@ -132,6 +164,7 @@ private slots:
     void pressAndHold();
     void pressOneAndTapAnother_data();
     void pressOneAndTapAnother();
+    void mask();
 
 private:
     int startDragDistance() const {
@@ -2247,6 +2280,34 @@ void tst_QQuickMouseArea::pressOneAndTapAnother()
     }
 }
 
+void tst_QQuickMouseArea::mask()
+{
+    QQuickView window;
+    QByteArray errorMessage;
+    QVERIFY2(initView(window, testFileUrl("mask.qml"), true, &errorMessage), errorMessage.constData());
+    window.show();
+    window.requestActivate();
+    QVERIFY(QTest::qWaitForWindowExposed(&window));
+    QQuickItem *root = window.rootObject();
+    QVERIFY(root != 0);
+
+    // click inside the mask, and verify it registers
+    QTest::mousePress(&window, Qt::LeftButton, 0, QPoint(100,100));
+    QTest::mouseRelease(&window, Qt::LeftButton, 0, QPoint(100,100));
+
+    QCOMPARE(window.rootObject()->property("pressed").toInt(), 1);
+    QCOMPARE(window.rootObject()->property("released").toInt(), 1);
+    QCOMPARE(window.rootObject()->property("clicked").toInt(), 1);
+
+    // click outside the mask (but inside the MouseArea), and verify it doesn't register
+    QTest::mousePress(&window, Qt::LeftButton, 0, QPoint(10,10));
+    QTest::mouseRelease(&window, Qt::LeftButton, 0, QPoint(10,10));
+
+    QCOMPARE(window.rootObject()->property("pressed").toInt(), 1);
+    QCOMPARE(window.rootObject()->property("released").toInt(), 1);
+    QCOMPARE(window.rootObject()->property("clicked").toInt(), 1);
+}
+
 QTEST_MAIN(tst_QQuickMouseArea)
 
 #include "tst_qquickmousearea.moc"