From: Alexey Verkhovsky <alex_verk@...>
Date: 2004-04-08T06:37:22+09:00
Subject: Re: building UIs with statecharts

Phil Tomson wrote:
> Do others use state-machines for [driving the logic of rich user interfaces]? 

Ain't know about Ruby [yet], but when writing thick GUIs in Java I use 
state machines for anything bigger than a simple popup dialog.

Resulting code is somewhat more verbose, but comes out rather stable due 
to very clean separation of buttons and logic.

In really complex situations, write a separate class for each state. 
Transition from state to state is then a factory method in the 
originating state, which creates an instance of the destination state, 
and passes control there. Main loop (translated to Ruby) is something like:

state = InitialState.new
state = state.getNextState until state.final?

Best regards,
Alexey Verkhovsky