Demo - Flex / StopWatch

This demo illustrates the use of the  StateMachine Utility to define and navigate the states of a  Finite State Machine or FSM of a working StopWatch.

Features in 1.0

• The following is a  Harel StateChart describing the FSM of a classic stopwatch:

• The demo implements this the above FSM as a working stopwatch, as  defined elsewhere and widely referred to as a familiar way to explain state machines in general.

• If you're confused what 'split/unsplit' mean, it is when you have the timer running, and you split the display to show a frozen lap time as of the moment you hit split, along with a continuing counter. This lets a coach easily note the lap times of individual runners in a race, for instance.

• It makes use of the FSMInjector which accepts an XML representation of the FSM for a stopwatch, registers the resultant StateMachine with the Facade.

• Check out the InjectFSMCommand for to see how easy it is to define the FSM and have it injected into your app.

• The question will certainly arise:
  • Why wasn't  SCXML chosen to define the FSM?
  • Several reasons:
    • Much more complex than we wanted to attempt.
    • Conditional logic is ugly because you have to escape ampersands in xml.
    • We wanted entering and exiting notifications for each state.
    • The word 'event' would inevitably cause confusion to the Flash community, so we chose 'action'.