summaryrefslogtreecommitdiffstats
path: root/doc/src/examples/factorial.qdoc
diff options
context:
space:
mode:
Diffstat (limited to 'doc/src/examples/factorial.qdoc')
-rw-r--r--doc/src/examples/factorial.qdoc102
1 files changed, 102 insertions, 0 deletions
diff --git a/doc/src/examples/factorial.qdoc b/doc/src/examples/factorial.qdoc
new file mode 100644
index 0000000..709a7c7
--- /dev/null
+++ b/doc/src/examples/factorial.qdoc
@@ -0,0 +1,102 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@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.
+
+ */