State Machine with Transitions

statemachinewithtransitions.cs

using TheNewStack;

namespace TheNewStack
{
    public enum TVState { OFF, STANDBY, CHANNEL1, CHANNEL2}

    public enum TVCommand { TURN_ON, TURN_OFF, SWITCH_TO_CHANNEL1, SWITCH_TO_CHANNEL2, SWITCH_OFF}

    public struct Transition
    {
        public TVState FromState;
        public TVState ToState;
        public TVCommand Command;

        public Transition(TVState fromState, TVState toState, TVCommand command)
        {
            FromState = fromState;
            ToState = toState;
            Command = command;
        }

    }

    public class StateMachineWithTransitions
    {
        private List<Transition> permittedTransitions;
        public TVState CurrentState;

        public StateMachineWithTransitions()
        {
            permittedTransitions = new List<Transition>()
            {
                new Transition(TVState.OFF, TVState.STANDBY, TVCommand.TURN_ON),
                new Transition(TVState.STANDBY, TVState.OFF, TVCommand.TURN_OFF),
                new Transition(TVState.STANDBY, TVState.CHANNEL1, TVCommand.SWITCH_TO_CHANNEL1),
                new Transition(TVState.CHANNEL2, TVState.CHANNEL1, TVCommand.SWITCH_TO_CHANNEL1),
                new Transition(TVState.CHANNEL2, TVState.STANDBY, TVCommand.SWITCH_OFF),
                new Transition(TVState.STANDBY, TVState.CHANNEL2, TVCommand.SWITCH_TO_CHANNEL2),
                new Transition(TVState.CHANNEL1, TVState.CHANNEL2, TVCommand.SWITCH_TO_CHANNEL2),
                new Transition(TVState.CHANNEL1, TVState.STANDBY, TVCommand.SWITCH_OFF),
            };

            CurrentState = TVState.OFF;
        }

        public Transition FindTransition(TVState fromState, TVCommand command)
        {
            Transition foundTransition = permittedTransitions.Find(transition => transition.FromState == fromState && transition.Command == command);

            return foundTransition;
        }

        public bool DoCommand(TVCommand command)
        {
            bool result = false;

            Transition transition = FindTransition(CurrentState, command);
            if (transition.FromState == CurrentState)
            {
                CurrentState = transition.ToState;
                Console.WriteLine(command + ": Now " + CurrentState);
                result = true;
            }

            return result;
        }
    }
}

public class Program
{

    static void Main(String[] args)
    {
        StateMachineWithTransitions s = new StateMachineWithTransitions();

        s.DoCommand(TVCommand.TURN_ON);
        s.DoCommand(TVCommand.SWITCH_TO_CHANNEL1);
        s.DoCommand(TVCommand.SWITCH_TO_CHANNEL2);
        s.DoCommand(TVCommand.SWITCH_TO_CHANNEL2);
        s.DoCommand(TVCommand.TURN_ON);
        s.DoCommand(TVCommand.SWITCH_OFF);
    }
}