diff -r 41300fa6a67c -r f7bc934e204c doc/src/examples/trafficlight.qdoc --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/doc/src/examples/trafficlight.qdoc Wed Mar 31 11:06:36 2010 +0300 @@ -0,0 +1,99 @@ +/**************************************************************************** +** +** Copyright (C) 2010 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/trafficlight + \title Traffic Light Example + + The Traffic Light example shows how to use \l{The State Machine Framework} + to implement the control flow of a traffic light. + + \image trafficlight-example.png + + In this example we write a TrafficLightWidget class. The traffic light has + three lights: Red, yellow and green. The traffic light transitions from + one light to another (red to yellow to green to yellow to red again) at + certain intervals. + + \snippet examples/statemachine/trafficlight/main.cpp 0 + + The LightWidget class represents a single light of the traffic light. It + provides an \c on property and two slots, turnOn() and turnOff(), to turn + the light on and off, respectively. The widget paints itself in the color + that's passed to the constructor. + + \snippet examples/statemachine/trafficlight/main.cpp 1 + + The TrafficLightWidget class represents the visual part of the traffic + light; it's a widget that contains three lights arranged vertically, and + provides accessor functions for these. + + \snippet examples/statemachine/trafficlight/main.cpp 2 + + The createLightState() function creates a state that turns a light on when + the state is entered, and off when the state is exited. The state uses a + timer, and as we shall see the timeout is used to transition from one + LightState to another. Here is the statechart for the light state: + + \img trafficlight-example1.png + \omit + \caption This is a caption + \endomit + + \snippet examples/statemachine/trafficlight/main.cpp 3 + + The TrafficLight class combines the TrafficLightWidget with a state + machine. The state graph has four states: red-to-yellow, yellow-to-green, + green-to-yellow and yellow-to-red. The initial state is red-to-yellow; + when the state's timer times out, the state machine transitions to + yellow-to-green. The same process repeats through the other states. + This is what the statechart looks like: + + \img trafficlight-example2.png + \omit + \caption This is a caption + \endomit + + \snippet examples/statemachine/trafficlight/main.cpp 4 + + The main() function constructs a TrafficLight and shows it. + +*/