diff options
| -rw-r--r-- | doc/src/examples.qdoc | 1 | ||||
| -rw-r--r-- | doc/src/examples/factorial.qdoc | 102 | ||||
| -rw-r--r-- | doc/src/images/factorial-example.png | bin | 0 -> 4032 bytes | |||
| -rw-r--r-- | examples/statemachine/factorial/main.cpp | 64 |
4 files changed, 141 insertions, 26 deletions
diff --git a/doc/src/examples.qdoc b/doc/src/examples.qdoc index 6fb903c475..660339036a 100644 --- a/doc/src/examples.qdoc +++ b/doc/src/examples.qdoc @@ -312,6 +312,7 @@ \list \o \l{statemachine/eventtransitions}{Event Transitions}\raisedaster + \o \l{statemachine/factorial}{Factorial States}\raisedaster \o \l{statemachine/pingpong}{Ping Pong States}\raisedaster \o \l{statemachine/trafficlight}{Traffic Light}\raisedaster \o \l{statemachine/twowaybutton}{Two-way Button}\raisedaster diff --git a/doc/src/examples/factorial.qdoc b/doc/src/examples/factorial.qdoc new file mode 100644 index 0000000000..2a72e0aff7 --- /dev/null +++ b/doc/src/examples/factorial.qdoc @@ -0,0 +1,102 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example statemachine/factorial + \title Factorial States Example + + The Factorial States example shows how to use \l{The State Machine + Framework} to calculate the factorial of an integer. + + The statechart for calculating the factorial looks as follows: + + \img factorial-example.png + \omit + \caption This is a caption + \endomit + + In other words, the state machine calculates the factorial of 6 and prints + the result. + + \snippet examples/statemachine/factorial/main.cpp 0 + + The Factorial class is used to hold the data of the computation, \c x and + \c fac. It also provides a signal that's emitted whenever the value of \c + x changes. + + \snippet examples/statemachine/factorial/main.cpp 1 + + The FactorialLoopTransition class implements the guard (\c x > 1) and + calculations (\c fac = \c x * \c fac; \c x = \c x - 1) of the factorial + loop. + + \snippet examples/statemachine/factorial/main.cpp 2 + + The FactorialDoneTransition class implements the guard (\c x <= 1) that + terminates the factorial computation. It also prints the final result to + standard output. + + \snippet examples/statemachine/factorial/main.cpp 3 + + The application's main() function first creates the application object, a + Factorial object and a state machine. + + \snippet examples/statemachine/factorial/main.cpp 4 + + The \c compute state is created, and the initial values of \c x and \c fac + are defined. A FactorialLoopTransition object is created and added to the + state. + + \snippet examples/statemachine/factorial/main.cpp 5 + + A final state, \c done, is created, and a FactorialDoneTransition object + is created with \c done as its target state. The transition is then added + to the \c compute state. + + \snippet examples/statemachine/factorial/main.cpp 6 + + The machine's initial state is set to be the \c compute state. We connect + the QStateMachine::finished() signal to the QCoreApplication::quit() slot, + so the application will quit when the state machine's work is + done. Finally, the state machine is started, and the application's event + loop is entered. + + */ diff --git a/doc/src/images/factorial-example.png b/doc/src/images/factorial-example.png Binary files differnew file mode 100644 index 0000000000..8fb1cc6925 --- /dev/null +++ b/doc/src/images/factorial-example.png diff --git a/examples/statemachine/factorial/main.cpp b/examples/statemachine/factorial/main.cpp index 2b6369052a..ae5928f091 100644 --- a/examples/statemachine/factorial/main.cpp +++ b/examples/statemachine/factorial/main.cpp @@ -48,6 +48,7 @@ #include <qfinalstate.h> #endif +//! [0] class Factorial : public QObject { Q_OBJECT @@ -55,10 +56,8 @@ class Factorial : public QObject Q_PROPERTY(int fac READ fac WRITE setFac) public: Factorial(QObject *parent = 0) - : QObject(parent) + : QObject(parent), m_x(-1), m_fac(1) { - m_fac = 1; - m_x = -1; } int x() const @@ -71,7 +70,7 @@ public: if (x == m_x) return; m_x = x; - emit xChanged(); + emit xChanged(x); } int fac() const @@ -85,28 +84,34 @@ public: } Q_SIGNALS: - void xChanged(); + 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())), m_fact(fact) + : QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact) {} - virtual bool eventTest(QEvent *) const + virtual bool eventTest(QEvent *e) const { - return m_fact->property("x").toInt() > 1; + if (!QSignalTransition::eventTest(e)) + return false; + QSignalEvent *se = static_cast<QSignalEvent*>(e); + return se->arguments().at(0).toInt() > 1; } - virtual void onTransition(QEvent *) + virtual void onTransition(QEvent *e) { - int x = m_fact->property("x").toInt(); + QSignalEvent *se = static_cast<QSignalEvent*>(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); @@ -115,17 +120,22 @@ public: private: Factorial *m_fact; }; +//! [1] +//! [2] class FactorialDoneTransition : public QSignalTransition { public: FactorialDoneTransition(Factorial *fact) - : QSignalTransition(fact, SIGNAL(xChanged())), m_fact(fact) + : QSignalTransition(fact, SIGNAL(xChanged(int))), m_fact(fact) {} - virtual bool eventTest(QEvent *) const + virtual bool eventTest(QEvent *e) const { - return m_fact->property("x").toInt() <= 1; + if (!QSignalTransition::eventTest(e)) + return false; + QSignalEvent *se = static_cast<QSignalEvent*>(e); + return se->arguments().at(0).toInt() <= 1; } virtual void onTransition(QEvent *) @@ -136,35 +146,37 @@ public: private: Factorial *m_fact; }; +//! [2] +//! [3] int main(int argc, char **argv) { QCoreApplication app(argc, argv); - Factorial factorial; - QStateMachine machine; +//! [3] - QState *computing = new QState(machine.rootState()); - computing->addTransition(new FactorialLoopTransition(&factorial)); +//! [4] + QState *compute = new QState(machine.rootState()); + compute->assignProperty(&factorial, "fac", 1); + compute->assignProperty(&factorial, "x", 6); + compute->addTransition(new FactorialLoopTransition(&factorial)); +//! [4] +//! [5] QFinalState *done = new QFinalState(machine.rootState()); FactorialDoneTransition *doneTransition = new FactorialDoneTransition(&factorial); doneTransition->setTargetState(done); - computing->addTransition(doneTransition); - - QState *initialize = new QState(machine.rootState()); - initialize->assignProperty(&factorial, "x", 6); - FactorialLoopTransition *enterLoopTransition = new FactorialLoopTransition(&factorial); - enterLoopTransition->setTargetState(computing); - initialize->addTransition(enterLoopTransition); + compute->addTransition(doneTransition); +//! [5] +//! [6] + machine.setInitialState(compute); QObject::connect(&machine, SIGNAL(finished()), &app, SLOT(quit())); - - machine.setInitialState(initialize); machine.start(); return app.exec(); } +//! [6] #include "main.moc" |
