#include <QtCore>
#include <stdio.h>
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;
};
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;
};
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;
};
int main(int argc, char **argv)
{
QCoreApplication app(argc, argv);
Factorial factorial;
QStateMachine machine;
QState *compute = new QState(&machine);
compute->assignProperty(&factorial, "fac", 1);
compute->assignProperty(&factorial, "x", 6);
compute->addTransition(new FactorialLoopTransition(&factorial));
QFinalState *done = new QFinalState(&machine);
FactorialDoneTransition *doneTransition = new FactorialDoneTransition(&factorial);
doneTransition->setTargetState(done);
compute->addTransition(doneTransition);
machine.setInitialState(compute);
QObject::connect(&machine, SIGNAL(finished()), &app, SLOT(quit()));
machine.start();
return app.exec();
}
#include "main.moc"