qt5base-lts/examples/widgets/statemachine/factorial/main.cpp

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/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the QtCore module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** 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 Digia Plc and its Subsidiary(-ies) 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 <QtCore>
#include <stdio.h>
//! [0]
class Factorial : public QObject
{
Q_OBJECT
Q_PROPERTY(int x READ x WRITE setX)
Q_PROPERTY(int fac READ fac WRITE setFac)
public:
Factorial(QObject *parent = 0)
: QObject(parent), m_x(-1), m_fac(1)
{
}
int x() const
{
return m_x;
}
void setX(int x)
{
if (x == m_x)
return;
m_x = x;
emit xChanged(x);
}
int fac() const
{
return m_fac;
}
void setFac(int fac)
{
m_fac = fac;
}
Q_SIGNALS:
void xChanged(int value);
private:
int m_x;
int m_fac;
};
//! [0]
//! [1]
class FactorialLoopTransition : public QSignalTransition
{
public:
FactorialLoopTransition(Factorial *fact)
: QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact)
{}
virtual bool eventTest(QEvent *e)
{
if (!QSignalTransition::eventTest(e))
return false;
QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);
return se->arguments().at(0).toInt() > 1;
}
virtual void onTransition(QEvent *e)
{
QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);
int x = se->arguments().at(0).toInt();
int fac = m_fact->property("fac").toInt();
m_fact->setProperty("fac", x * fac);
m_fact->setProperty("x", x - 1);
}
private:
Factorial *m_fact;
};
//! [1]
//! [2]
class FactorialDoneTransition : public QSignalTransition
{
public:
FactorialDoneTransition(Factorial *fact)
: QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact)
{}
virtual bool eventTest(QEvent *e)
{
if (!QSignalTransition::eventTest(e))
return false;
QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);
return se->arguments().at(0).toInt() <= 1;
}
virtual void onTransition(QEvent *)
{
fprintf(stdout, "%d\n", m_fact->property("fac").toInt());
}
private:
Factorial *m_fact;
};
//! [2]
//! [3]
int main(int argc, char **argv)
{
QCoreApplication app(argc, argv);
Factorial factorial;
QStateMachine machine;
//! [3]
//! [4]
QState *compute = new QState(&machine);
compute->assignProperty(&factorial, "fac", 1);
compute->assignProperty(&factorial, "x", 6);
compute->addTransition(new FactorialLoopTransition(&factorial));
//! [4]
//! [5]
QFinalState *done = new QFinalState(&machine);
FactorialDoneTransition *doneTransition = new FactorialDoneTransition(&factorial);
doneTransition->setTargetState(done);
compute->addTransition(doneTransition);
//! [5]
//! [6]
machine.setInitialState(compute);
QObject::connect(&machine, SIGNAL(finished()), &app, SLOT(quit()));
machine.start();
return app.exec();
}
//! [6]
#include "main.moc"