document the statemachine/pingpong example

4 files changed, 122 insertions, 0 deletions

diff --git a/doc/src/examples.qdoc b/doc/src/examples.qdoc
index 06d7727..4bedcde 100644
--- a/doc/src/examples.qdoc
+++ b/doc/src/examples.qdoc
@@ -312,6 +312,7 @@
 
     \list
     \o \l{statemachine/trafficlight}{Traffic Light}\raisedaster
+    \o \l{statemachine/pingpong}{Ping Pong States}\raisedaster
     \endlist
 
     \section1 Threads
diff --git a/doc/src/examples/pingpong.qdoc b/doc/src/examples/pingpong.qdoc
new file mode 100644
index 0000000..040e429
--- /dev/null
+++ b/doc/src/examples/pingpong.qdoc
@@ -0,0 +1,107 @@
+/****************************************************************************
+**
+** 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/pingpong
+    \title Ping Pong States Example
+
+    The Ping Pong States example shows how to use parallel states together
+    with custom events and transitions in \l{The State Machine Framework}.
+
+    This example implements a statechart where two states communicate by
+    posting events to the state machine. The state chart looks as follows:
+
+    \img pingpong-example.png
+    \omit
+    \caption This is a caption
+    \endomit
+
+    The \c pinger and \c ponger states are parallel states, i.e. they are
+    entered simultaneously and will take transitions independently of
+    eachother.
+
+    The \c pinger state will post the first \c ping event upon entry; the \c
+    ponger state will respond by posting a \c pong event; this will cause the
+    \c pinger state to post a new \c ping event; and so on.
+
+    \snippet examples/statemachine/pingpong/main.cpp 0
+
+    Two custom events are defined, \c PingEvent and \c PongEvent.
+
+    \snippet examples/statemachine/pingpong/main.cpp 1
+
+    The \c Pinger class defines a state that posts a \c PingEvent to the state
+    machine when the state is entered.
+
+    \snippet examples/statemachine/pingpong/main.cpp 2
+
+    The \c PingTransition class defines a transition that is triggered by
+    events of type \c PingEvent, and that posts a \c PongEvent (with a delay
+    of 500 milliseconds) to the state machine when the transition is
+    triggered.
+
+    \snippet examples/statemachine/pingpong/main.cpp 3
+
+    The \c PongTransition class defines a transition that is triggered by
+    events of type \c PongEvent, and that posts a \c PingEvent (with a delay
+    of 500 milliseconds) to the state machine when the transition is
+    triggered.
+
+    \snippet examples/statemachine/pingpong/main.cpp 4
+
+    The main() function begins by creating a state machine and a parallel
+    state group.
+
+    \snippet examples/statemachine/pingpong/main.cpp 5
+
+    Next, the \c pinger and \c ponger states are created, with the parallel
+    state group as their parent state. Note that the transitions are \e
+    targetless. When such a transition is triggered, the source state won't be
+    exited and re-entered; only the transition's onTransition() function will
+    be called, and the state machine's configuration will remain the same,
+    which is precisely what we want in this case.
+
+    \snippet examples/statemachine/pingpong/main.cpp 6
+
+    Finally, the group is added to the state machine, the machine is started,
+    and the application event loop is entered.
+
+  */
diff --git a/doc/src/images/pingpong-example.png b/doc/src/images/pingpong-example.png
new file mode 100644
index 0000000..af707e4
--- /dev/null
+++ b/doc/src/images/pingpong-example.png
diff --git a/examples/statemachine/pingpong/main.cpp b/examples/statemachine/pingpong/main.cpp
index eb8fd5d..db66bfd 100644
--- a/examples/statemachine/pingpong/main.cpp
+++ b/examples/statemachine/pingpong/main.cpp
@@ -47,6 +47,7 @@
 #include <qabstracttransition.h>
 #endif
 
+//! [0]
 class PingEvent : public QEvent
 {
 public:
@@ -60,7 +61,9 @@ public:
     PongEvent() : QEvent(QEvent::Type(QEvent::User+3))
         {}
 };
+//! [0]
 
+//! [1]
 class Pinger : public QState
 {
 public:
@@ -74,7 +77,9 @@ protected:
         fprintf(stdout, "ping?\n");
     }
 };
+//! [1]
 
+//! [3]
 class PongTransition : public QAbstractTransition
 {
 public:
@@ -90,7 +95,9 @@ protected:
         fprintf(stdout, "ping?\n");
     }
 };
+//! [3]
 
+//! [2]
 class PingTransition : public QAbstractTransition
 {
 public:
@@ -106,7 +113,9 @@ protected:
         fprintf(stdout, "pong!\n");
     }
 };
+//! [2]
 
+//! [4]
 int main(int argc, char **argv)
 {
     QCoreApplication app(argc, argv);
@@ -114,7 +123,9 @@ int main(int argc, char **argv)
     QStateMachine machine;
     QState *group = new QState(QState::ParallelStates);
     group->setObjectName("group");
+//! [4]
 
+//! [5]
     Pinger *pinger = new Pinger(group);
     pinger->setObjectName("pinger");
     pinger->addTransition(new PongTransition());
@@ -122,10 +133,13 @@ int main(int argc, char **argv)
     QState *ponger = new QState(group);
     ponger->setObjectName("ponger");
     ponger->addTransition(new PingTransition());
+//! [5]
 
+//! [6]
     machine.addState(group);
     machine.setInitialState(group);
     machine.start();
 
     return app.exec();
 }
+//! [6]