A Simple State Machine

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using System.Reflection; 

namespace AbstractFSM
{
    public partial class frmTest : Form
    {
        public frmTest()
        {
            InitializeComponent();
        }

        private StatesManager m_player = null;
        private void frmTest_Load(object sender, EventArgs e)
        {
            //fill the playlist
            lstSongs.Items.Clear();
            for (int i = 0; i <= 19; i++)
            {
                lstSongs.Items.Add(i.ToString("000") + " - Song" + i.ToString());     
            }
            //
            m_player = new MediaPlayerStateManager(this); 
        }

        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new frmTest());
        }

        private void btnStop_Click(object sender, EventArgs e)
        {
            m_player.ChangeState(sender, new StateEventArgs((int)StateEvents.Stop));
            EnablePlayerControl();
        }

        private void btnPlay_Click(object sender, EventArgs e)
        {
            m_player.ChangeState(sender, new StateEventArgs((int)StateEvents.Play));
            EnablePlayerControl();
        }

        private void btnPause_Click(object sender, EventArgs e)
        {
            m_player.ChangeState(sender, new StateEventArgs((int)StateEvents.Pause));
            EnablePlayerControl();
        }

        private void btnPrevious_Click(object sender, EventArgs e)
        {
            m_player.ChangeState(sender, new StateEventArgs((int)StateEvents.Previos));
            EnablePlayerControl();
        }

        private void btnNext_Click(object sender, EventArgs e)
        {
            m_player.ChangeState(sender, new StateEventArgs((int)StateEvents.Next));
            EnablePlayerControl();
        }

        private void lstSongs_SelectedIndexChanged(object sender, EventArgs e)
        {
            grpPlayPanel.Enabled = (lstSongs.SelectedIndex != -1); 
        }

        private void btnClearStatesList_Click(object sender, EventArgs e)
        {
            lstStates.Items.Clear();   
        }
        //
        private void EnablePlayerControl()
        {
            btnStop.Enabled = m_player.CheckState(this, new StateEventArgs((int)StateEvents.Stop));
            btnPlay.Enabled = m_player.CheckState(this, new StateEventArgs((int)StateEvents.Play));
            btnPause.Enabled = m_player.CheckState(this, new StateEventArgs((int)StateEvents.Stop));
            btnPrevious.Enabled = m_player.CheckState(this, new StateEventArgs((int)StateEvents.Previos));
            btnNext.Enabled = m_player.CheckState(this, new StateEventArgs((int)StateEvents.Next));
        }
    }

    public enum StateEvents
    {
        Stop, Play, Pause, Previos, Next
    }
    
    //////////////////////////////////////////////////////////////////////////////


}