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| 2 | **
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| 3 | ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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| 40 | ****************************************************************************/
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| 41 |
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| 42 | /*!
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| 43 | \example statemachine/pingpong
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| 44 | \title Ping Pong States Example
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| 45 |
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| 46 | The Ping Pong States example shows how to use parallel states together
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| 47 | with custom events and transitions in \l{The State Machine Framework}.
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| 48 |
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| 49 | This example implements a statechart where two states communicate by
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| 50 | posting events to the state machine. The state chart looks as follows:
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| 51 |
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| 52 | \img pingpong-example.png
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| 53 | \omit
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| 54 | \caption This is a caption
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| 55 | \endomit
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| 56 |
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| 57 | The \c pinger and \c ponger states are parallel states, i.e. they are
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| 58 | entered simultaneously and will take transitions independently of
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| 59 | eachother.
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| 60 |
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| 61 | The \c pinger state will post the first \c ping event upon entry; the \c
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| 62 | ponger state will respond by posting a \c pong event; this will cause the
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| 63 | \c pinger state to post a new \c ping event; and so on.
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| 64 |
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| 65 | \snippet examples/statemachine/pingpong/main.cpp 0
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| 66 |
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| 67 | Two custom events are defined, \c PingEvent and \c PongEvent.
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| 68 |
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| 69 | \snippet examples/statemachine/pingpong/main.cpp 1
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| 70 |
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| 71 | The \c Pinger class defines a state that posts a \c PingEvent to the state
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| 72 | machine when the state is entered.
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| 73 |
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| 74 | \snippet examples/statemachine/pingpong/main.cpp 2
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| 75 |
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| 76 | The \c PingTransition class defines a transition that is triggered by
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| 77 | events of type \c PingEvent, and that posts a \c PongEvent (with a delay
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| 78 | of 500 milliseconds) to the state machine when the transition is
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| 79 | triggered.
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| 80 |
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| 81 | \snippet examples/statemachine/pingpong/main.cpp 3
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| 82 |
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| 83 | The \c PongTransition class defines a transition that is triggered by
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| 84 | events of type \c PongEvent, and that posts a \c PingEvent (with a delay
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| 85 | of 500 milliseconds) to the state machine when the transition is
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| 86 | triggered.
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| 87 |
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| 88 | \snippet examples/statemachine/pingpong/main.cpp 4
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| 89 |
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| 90 | The main() function begins by creating a state machine and a parallel
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| 91 | state group.
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| 92 |
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| 93 | \snippet examples/statemachine/pingpong/main.cpp 5
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| 94 |
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| 95 | Next, the \c pinger and \c ponger states are created, with the parallel
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| 96 | state group as their parent state. Note that the transitions are \e
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| 97 | targetless. When such a transition is triggered, the source state won't be
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| 98 | exited and re-entered; only the transition's onTransition() function will
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| 99 | be called, and the state machine's configuration will remain the same,
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| 100 | which is precisely what we want in this case.
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| 101 |
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| 102 | \snippet examples/statemachine/pingpong/main.cpp 6
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| 103 |
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| 104 | Finally, the group is added to the state machine, the machine is started,
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| 105 | and the application event loop is entered.
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| 106 |
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| 107 | */
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