1 files changed, 85 insertions, 0 deletions
diff --git a/doc/src/examples/trafficlight.qdoc b/doc/src/examples/trafficlight.qdoc
new file mode 100644
index 0000000000..25cb198aeb
--- /dev/null
+++ b/doc/src/examples/trafficlight.qdoc
@@ -0,0 +1,85 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 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.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** 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 Free Documentation License
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of this
+** file.
+**
+** 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.
+
+*/