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    16 ** GNU Lesser General Public License Usage

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    40 ****************************************************************************/

    41 

    42 #include <QtCore>

    43 #include <stdio.h>

    44 

    45 //! [0]

    46 class Factorial : public QObject

    47 {

    48     Q_OBJECT

    49     Q_PROPERTY(int x READ x WRITE setX)

    50     Q_PROPERTY(int fac READ fac WRITE setFac)

    51 public:

    52     Factorial(QObject *parent = 0)

    53         : QObject(parent), m_x(-1), m_fac(1)

    54     {

    55     }

    56 

    57     int x() const

    58     {

    59         return m_x;

    60     }

    61 

    62     void setX(int x)

    63     {

    64         if (x == m_x)

    65             return;

    66         m_x = x;

    67         emit xChanged(x);

    68     }

    69 

    70     int fac() const

    71     {

    72         return m_fac;

    73     }

    74 

    75     void setFac(int fac)

    76     {

    77         m_fac = fac;

    78     }

    79 

    80 Q_SIGNALS:

    81     void xChanged(int value);

    82     

    83 private:

    84     int m_x;

    85     int m_fac;

    86 };

    87 //! [0]

    88 

    89 //! [1]

    90 class FactorialLoopTransition : public QSignalTransition

    91 {

    92 public:

    93     FactorialLoopTransition(Factorial *fact)

    94         : QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact)

    95     {}

    96 

    97     virtual bool eventTest(QEvent *e)

    98     {

    99         if (!QSignalTransition::eventTest(e))

   100             return false;

   101         QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);

   102         return se->arguments().at(0).toInt() > 1;

   103     }

   104 

   105     virtual void onTransition(QEvent *e)

   106     {

   107         QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);

   108         int x = se->arguments().at(0).toInt();

   109         int fac = m_fact->property("fac").toInt();

   110         m_fact->setProperty("fac",  x * fac);

   111         m_fact->setProperty("x",  x - 1);

   112     }

   113 

   114 private:

   115     Factorial *m_fact;

   116 };

   117 //! [1]

   118 

   119 //! [2]

   120 class FactorialDoneTransition : public QSignalTransition

   121 {

   122 public:

   123     FactorialDoneTransition(Factorial *fact)

   124         : QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact)

   125     {}

   126 

   127     virtual bool eventTest(QEvent *e)

   128     {

   129         if (!QSignalTransition::eventTest(e))

   130             return false;

   131         QStateMachine::SignalEvent *se = static_cast<QStateMachine::SignalEvent*>(e);

   132         return se->arguments().at(0).toInt() <= 1;

   133     }

   134 

   135     virtual void onTransition(QEvent *)

   136     {

   137         fprintf(stdout, "%d\n", m_fact->property("fac").toInt());

   138     }

   139 

   140 private:

   141     Factorial *m_fact;

   142 };

   143 //! [2]

   144 

   145 //! [3]

   146 int main(int argc, char **argv)

   147 {

   148     QCoreApplication app(argc, argv);

   149     Factorial factorial;

   150     QStateMachine machine;

   151 //! [3]

   152 

   153 //! [4]

   154     QState *compute = new QState(&machine);

   155     compute->assignProperty(&factorial, "fac", 1);

   156     compute->assignProperty(&factorial, "x", 6);

   157     compute->addTransition(new FactorialLoopTransition(&factorial));

   158 //! [4]

   159 

   160 //! [5]

   161     QFinalState *done = new QFinalState(&machine);

   162     FactorialDoneTransition *doneTransition = new FactorialDoneTransition(&factorial);

   163     doneTransition->setTargetState(done);

   164     compute->addTransition(doneTransition);

   165 //! [5]

   166 

   167 //! [6]

   168     machine.setInitialState(compute);

   169     QObject::connect(&machine, SIGNAL(finished()), &app, SLOT(quit()));

   170     machine.start();

   171 

   172     return app.exec();

   173 }

   174 //! [6]

   175 

   176 #include "main.moc"