Add a sudoku example

Change-Id: I08a0c053a195dd55e6ff796b89a19ee160eb152d
Reviewed-by: Erik Verbruggen <erik.verbruggen@qt.io>

10 files changed, 674 insertions, 0 deletions

diff --git a/examples/scxml/scxml.pro b/examples/scxml/scxml.pro
index 081304f..8da9db6 100644
--- a/examples/scxml/scxml.pro
+++ b/examples/scxml/scxml.pro
@@ -7,6 +7,7 @@ qtHaveModule(widgets) {
     SUBDIRS +=  mediaplayer-widgets-dynamic
     SUBDIRS +=  calculator-widgets
     SUBDIRS +=  pinball
+    SUBDIRS +=  sudoku
 }
 
 qtHaveModule(qml) {
diff --git a/examples/scxml/sudoku/data/nearly-solved-sudoku.data b/examples/scxml/sudoku/data/nearly-solved-sudoku.data
new file mode 100644
index 0000000..0e5c31f
--- /dev/null
+++ b/examples/scxml/sudoku/data/nearly-solved-sudoku.data
@@ -0,0 +1,9 @@
+0, 3, 5, 2, 6, 9, 7, 8, 1
+6, 8, 2, 5, 7, 1, 4, 9, 3
+1, 9, 7, 8, 3, 4, 5, 6, 2
+8, 2, 6, 1, 9, 5, 3, 4, 7
+3, 7, 4, 6, 8, 2, 9, 1, 5
+9, 5, 1, 7, 4, 3, 6, 2, 8
+5, 1, 9, 3, 2, 6, 8, 7, 4
+2, 4, 8, 9, 5, 7, 1, 3, 6
+7, 6, 3, 4, 1, 8, 2, 5, 9
diff --git a/examples/scxml/sudoku/data/sudoku.data b/examples/scxml/sudoku/data/sudoku.data
new file mode 100644
index 0000000..342fdf0
--- /dev/null
+++ b/examples/scxml/sudoku/data/sudoku.data
@@ -0,0 +1,9 @@
+0, 0, 0, 2, 6, 0, 7, 0, 1
+6, 8, 0, 0, 7, 0, 0, 9, 0
+1, 9, 0, 0, 0, 4, 5, 0, 0
+8, 2, 0, 1, 0, 0, 0, 4, 0
+0, 0, 4, 6, 0, 2, 9, 0, 0
+0, 5, 0, 0, 0, 3, 0, 2, 8
+0, 0, 9, 3, 0, 0, 0, 7, 4
+0, 4, 0, 0, 5, 0, 0, 3, 6
+7, 0, 3, 0, 1, 8, 0, 0, 0
diff --git a/examples/scxml/sudoku/main.cpp b/examples/scxml/sudoku/main.cpp
new file mode 100644
index 0000000..0af8d72
--- /dev/null
+++ b/examples/scxml/sudoku/main.cpp
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtScxml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "sudoku.h"
+#include "mainwindow.h"
+
+#include <QApplication>
+
+int main(int argc, char **argv)
+{
+    QApplication app(argc, argv);
+
+    Sudoku machine;
+    MainWindow mainWindow(&machine);
+
+    machine.start();
+    mainWindow.show();
+    return app.exec();
+}
diff --git a/examples/scxml/sudoku/mainwindow.cpp b/examples/scxml/sudoku/mainwindow.cpp
new file mode 100644
index 0000000..574b5ca
--- /dev/null
+++ b/examples/scxml/sudoku/mainwindow.cpp
@@ -0,0 +1,237 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtScxml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "mainwindow.h"
+
+#include <QStringListModel>
+#include <QScxmlStateMachine>
+#include <QComboBox>
+#include <QToolButton>
+#include <QLabel>
+#include <QGridLayout>
+#include <QFile>
+#include <QDir>
+#include <QTextStream>
+
+static int Size = 9;
+
+QT_USE_NAMESPACE
+
+static QVariantList emptyRow()
+{
+    QVariantList row;
+    for (int i = 0; i < Size; i++)
+        row.append(QVariant(0));
+    return row;
+}
+
+static QVariantMap readSudoku(const QString &fileName)
+{
+    QFile input(fileName);
+    input.open(QIODevice::ReadOnly | QIODevice::Text);
+    QTextStream str(&input);
+    const QString data = str.readAll();
+
+    QVariantList initRowsVariant;
+    const QStringList rows = data.split(QLatin1Char('\n'));
+    for (int i = 0; i < Size; i++) {
+        if (i < rows.count()) {
+            QVariantList initRowVariant;
+            const QStringList row = rows.at(i).split(QLatin1Char(','));
+            for (int j = 0; j < Size; j++) {
+                const int val = j < row.count()
+                        ? row.at(j).toInt() % (Size + 1) : 0;
+                initRowVariant.append(val);
+            }
+            initRowsVariant.append(QVariant(initRowVariant));
+        } else {
+            initRowsVariant.append(QVariant(emptyRow()));
+        }
+    }
+
+    QVariantMap dataVariant;
+    dataVariant.insert(QStringLiteral("initState"), initRowsVariant);
+
+    return dataVariant;
+}
+
+MainWindow::MainWindow(QScxmlStateMachine *machine, QWidget *parent) :
+    QWidget(parent),
+    m_machine(machine)
+{
+    const QVector<QToolButton *> initVector(Size, nullptr);
+    m_buttons = QVector<QVector<QToolButton *> >(Size, initVector);
+
+    QGridLayout *layout = new QGridLayout(this);
+
+    for (int i = 0; i < Size; i++) {
+        for (int j = 0; j < Size; j++) {
+            QToolButton *button = new QToolButton(this);
+            button->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+            layout->addWidget(button, i + i / 3, j + j / 3);
+            m_buttons[i][j] = button;
+            connect(button, &QToolButton::clicked, [this, i, j] () {
+                QVariantMap data;
+                data.insert(QStringLiteral("x"), i);
+                data.insert(QStringLiteral("y"), j);
+                m_machine->submitEvent("tap", data);
+            });
+        }
+    }
+
+    for (int i = 0; i < 3; i++) {
+        for (int j = 0; j < 2; j++) {
+            QFrame *hFrame = new QFrame(this);
+            hFrame->setFrameShape(QFrame::HLine);
+            layout->addWidget(hFrame, 4 * j + 3, 4 * i, 1, 3);
+
+            QFrame *vFrame = new QFrame(this);
+            vFrame->setFrameShape(QFrame::VLine);
+            layout->addWidget(vFrame, 4 * i, 4 * j + 3, 3, 1);
+        }
+    }
+
+    m_startButton = new QToolButton(this);
+    m_startButton->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    m_startButton->setText(tr("Start"));
+    layout->addWidget(m_startButton, Size + 3, 0, 1, 3);
+
+    connect(m_startButton, &QAbstractButton::clicked,
+            [this] {
+        if (m_machine->isActive("playing"))
+            m_machine->submitEvent("stop");
+        else
+            m_machine->submitEvent("start");
+    });
+
+    m_label = new QLabel(tr("unsolved"));
+    m_label->setAlignment(Qt::AlignCenter);
+    layout->addWidget(m_label, Size + 3, 4, 1, 3);
+
+    m_undoButton = new QToolButton(this);
+    m_undoButton->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
+    m_undoButton->setText(tr("Undo"));
+    layout->addWidget(m_undoButton, Size + 3, 8, 1, 3);
+
+    connect(m_undoButton, &QAbstractButton::clicked,
+            [this] {
+        m_machine->submitEvent("undo");
+    });
+
+    m_chooser = new QComboBox(this);
+    layout->addWidget(m_chooser, Size + 4, 0, 1, 11);
+
+    QDir dataDir(QLatin1String(":/data"));
+    QFileInfoList sudokuFiles = dataDir.entryInfoList(QStringList() << "*.data");
+    foreach (const QFileInfo &sudokuFile, sudokuFiles)
+        m_chooser->addItem(sudokuFile.completeBaseName(), sudokuFile.absoluteFilePath());
+
+    connect(m_chooser, static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+            [this] (int index) {
+        const QString sudokuFile = m_chooser->itemData(index).toString();
+        const QVariantMap initValues = readSudoku(sudokuFile);
+        m_machine->submitEvent("setup", initValues);
+    });
+
+    const QVariantMap initValues = readSudoku(m_chooser->itemData(0).toString());
+    m_machine->setInitialValues(initValues);
+
+    m_machine->connectToState("playing", [this] (bool playing) {
+        if (playing) {
+            m_startButton->setText(tr("Stop"));
+            m_undoButton->setEnabled(true);
+            m_chooser->setEnabled(false);
+        } else {
+            m_startButton->setText(tr("Start"));
+            m_undoButton->setEnabled(false);
+            m_chooser->setEnabled(true);
+        }
+    });
+
+    m_machine->connectToState("solved", [this] (bool solved) {
+        if (solved)
+            m_label->setText(tr("SOLVED !!!"));
+        else
+            m_label->setText(tr("unsolved"));
+    });
+
+    m_machine->connectToEvent("updateGUI", [this] (const QScxmlEvent &event) {
+        const QVariant data = event.data();
+
+        const QVariantList currentRows = data.toMap().value("currentState").toList();
+        for (int i = 0; i < currentRows.count(); i++) {
+            const QVariantList row = currentRows.at(i).toList();
+            for (int j = 0; j < row.count(); j++) {
+                const int value = row.at(j).toInt();
+                const QString text = value ? QString::number(value) : QString();
+                m_buttons[i][j]->setText(text);
+            }
+        }
+
+        const bool active = m_machine->isActive("playing");
+
+        const QVariantList initRows = data.toMap().value("initState").toList();
+        for (int i = 0; i < initRows.count(); i++) {
+            const QVariantList row = initRows.at(i).toList();
+            for (int j = 0; j < row.count(); j++) {
+                const int value = row.at(j).toInt();
+                const bool enabled = !value && active; // enable only zeroes from initState
+                m_buttons[i][j]->setEnabled(enabled);
+            }
+        }
+    });
+
+    setLayout(layout);
+}
+
+MainWindow::~MainWindow()
+{
+}
+
diff --git a/examples/scxml/sudoku/mainwindow.h b/examples/scxml/sudoku/mainwindow.h
new file mode 100644
index 0000000..99a0f1b
--- /dev/null
+++ b/examples/scxml/sudoku/mainwindow.h
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtScxml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QWidget>
+
+QT_BEGIN_NAMESPACE
+class QToolButton;
+class QScxmlStateMachine;
+class QLabel;
+class QComboBox;
+QT_END_NAMESPACE
+
+
+class MainWindow : public QWidget
+{
+    Q_OBJECT
+
+public:
+    explicit MainWindow(QScxmlStateMachine *machine, QWidget *parent = 0);
+    ~MainWindow();
+
+private:
+    QScxmlStateMachine *m_machine;
+    QVector<QVector<QToolButton *> > m_buttons;
+    QToolButton *m_startButton;
+    QToolButton *m_undoButton;
+    QLabel *m_label;
+    QComboBox *m_chooser;
+};
+
+#endif // MAINWINDOW_H
diff --git a/examples/scxml/sudoku/sudoku.js b/examples/scxml/sudoku/sudoku.js
new file mode 100644
index 0000000..afd9691
--- /dev/null
+++ b/examples/scxml/sudoku/sudoku.js
@@ -0,0 +1,130 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtScxml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+function restart() {
+    for (var i = 0; i < initState.length; i++)
+        currentState[i] = initState[i].slice();
+    undoStack = [];
+}
+
+function isValidPosition() {
+    var x = _event.data.x;
+    var y = _event.data.y;
+    if (x < 0 || x >= initState.length)
+        return false;
+    if (y < 0 || y >= initState.length)
+        return false;
+    if (initState[x][y] !== 0)
+        return false;
+    return true;
+}
+
+function calculateCurrentState() {
+    if (isValidPosition() === false)
+        return
+    var x = _event.data.x;
+    var y = _event.data.y;
+    var currentValue = currentState[x][y];
+    if (currentValue === initState.length)
+        currentValue = 0;
+    else
+        currentValue += 1;
+    currentState[x][y] = currentValue;
+    undoStack.push([x, y]);
+}
+
+function isOK(numbers) {
+    var temp = [];
+    for (var i = 0; i < numbers.length; i++) {
+        var currentValue = numbers[i];
+        if (currentValue === 0)
+            return false;
+        if (temp.indexOf(currentValue) >= 0)
+            return false;
+        temp.push(currentValue);
+    }
+    return true;
+}
+
+function isSolved() {
+    for (var i = 0; i < currentState.length; i++) {
+        if (!isOK(currentState[i]))
+            return false;
+
+        var column = [];
+        var square = [];
+        for (var j = 0; j < currentState[i].length; j++) {
+            column.push(currentState[j][i]);
+            square.push(currentState[Math.floor(i / 3) * 3 + Math.floor(j / 3)]
+                                    [i % 3 * 3 + j % 3]);
+        }
+
+        if (!isOK(column))
+            return false;
+        if (!isOK(square))
+            return false;
+    }
+    return true;
+}
+
+function undo() {
+    if (!undoStack.length)
+        return;
+
+    var lastMove = undoStack.pop();
+    var x = lastMove[0];
+    var y = lastMove[1];
+    var currentValue = currentState[x][y];
+    if (currentValue === 0)
+        currentValue = initState.length;
+    else
+        currentValue -= 1;
+    currentState[x][y] = currentValue;
+}
diff --git a/examples/scxml/sudoku/sudoku.pro b/examples/scxml/sudoku/sudoku.pro
new file mode 100644
index 0000000..0853a5e
--- /dev/null
+++ b/examples/scxml/sudoku/sudoku.pro
@@ -0,0 +1,19 @@
+QT += widgets scxml
+
+CONFIG += c++11
+
+STATECHARTS = sudoku.scxml
+
+SOURCES += \
+    main.cpp \
+    mainwindow.cpp
+
+HEADERS += \
+    mainwindow.h
+
+RESOURCES += \
+    sudoku.qrc
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/scxml/sudoku
+INSTALLS += target
diff --git a/examples/scxml/sudoku/sudoku.qrc b/examples/scxml/sudoku/sudoku.qrc
new file mode 100644
index 0000000..6a15532
--- /dev/null
+++ b/examples/scxml/sudoku/sudoku.qrc
@@ -0,0 +1,8 @@
+<RCC>
+    <qresource prefix="/">
+        <file>sudoku.js</file>
+        <file>data/sudoku.data</file>
+        <file>data/nearly-solved-sudoku.data</file>
+    </qresource>
+</RCC>
+
diff --git a/examples/scxml/sudoku/sudoku.scxml b/examples/scxml/sudoku/sudoku.scxml
new file mode 100644
index 0000000..ac447cc
--- /dev/null
+++ b/examples/scxml/sudoku/sudoku.scxml
@@ -0,0 +1,114 @@
+<?xml version="1.0" ?>
+<!--
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtScxml module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** 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.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     contributors may be used to endorse or promote products derived
+**     from this software without specific prior written permission.
+**
+**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+-->
+<scxml xmlns="http://www.w3.org/2005/07/scxml" version="1.0"
+       name="Sudoku" datamodel="ecmascript">
+    <datamodel>
+        <data id="initState"/>
+        <data id="currentState" expr="[[]]"/>
+        <data id="undoStack"/>
+    </datamodel>
+    <script src="sudoku.js"/>
+    <state id="game">
+        <onentry>
+            <raise event="restart"/>
+        </onentry>
+        <state id="idle">
+            <onentry>
+                <raise event="update"/>
+            </onentry>
+            <transition event="start" target="playing"/>
+            <transition event="setup" target="unsolved">
+                <assign location="initState" expr="_event.data.initState"/>
+                <raise event="restart"/>
+            </transition>
+            <state id="unsolved"/>
+            <state id="solved"/>
+        </state>
+        <state id="playing">
+            <onentry>
+                <raise event="restart"/>
+            </onentry>
+            <transition event="tap">
+                <if cond="isValidPosition()">
+                    <script>
+                        calculateCurrentState();
+                    </script>
+                    <if cond="isSolved()">
+                        <raise event="solved"/>
+                    </if>
+                    <raise event="update"/>
+                </if>
+            </transition>
+            <transition event="undo">
+                <script>
+                    undo();
+                </script>
+                <raise event="update"/>
+            </transition>
+            <transition event="stop" target="idle"/>
+            <transition event="solved" target="solved"/>
+        </state>
+        <transition event="restart">
+            <script>
+                restart();
+            </script>
+            <raise event="update"/>
+        </transition>
+        <transition event="update">
+            <send event="updateGUI">
+                <param name="currentState" expr="currentState"/>
+                <param name="initState" expr="initState"/>
+            </send>
+        </transition>
+    </state>
+</scxml>