ConsoleEventHandler.cs :  » Build-Systems » CruiseControl.NET » ThoughtWorks » CruiseControl » Core » C# / CSharp Open Source

using System;
using System.Runtime.InteropServices;
using ThoughtWorks.CruiseControl.Core.Util;

namespace ThoughtWorks.CruiseControl.Core{
  /// <summary>
  /// Intercepts events raised by the command console.
  /// </summary>
  public class ConsoleEventHandler : IDisposable
  {
    private ControlEventHandler handler;
    private ExecutionEnvironment environment = new ExecutionEnvironment();
    public event EventHandler OnConsoleEvent;

    public ConsoleEventHandler()
    {
      if (environment.IsRunningOnWindows)
      {
        handler = new ControlEventHandler(HandleControlEvent);
        SetConsoleCtrlHandler(handler, true);
      }
    }


    private void HandleControlEvent(ConsoleEvent consoleEvent)
    {
      lock (this)
      {
        if (OnConsoleEvent != null)
        {
          OnConsoleEvent(this, EventArgs.Empty);
        }
      }
    }

    void IDisposable.Dispose()
    {
      lock (this)
      {
        UnregisterHandler();
      }
    }

    private void UnregisterHandler()
    {
      if (handler != null)
      {
        SetConsoleCtrlHandler(handler, false);
        handler = null;
      }
    }

    private delegate void ControlEventHandler(ConsoleEvent consoleEvent);

    // From wincom.h
    private enum ConsoleEvent
    {
      CTRL_C = 0,
      CTRL_BREAK = 1,
      CTRL_CLOSE = 2,
      CTRL_LOGOFF = 5,
      CTRL_SHUTDOWN = 6
    }

    [DllImport("kernel32.dll")]
    private static extern bool SetConsoleCtrlHandler(ControlEventHandler e, bool add);
  }
}