/*************************************************************************************

   Extended WPF Toolkit

   Copyright (C) 2007-2013 Xceed Software Inc.

   This program is provided to you under the terms of the Microsoft Public
   License (Ms-PL) as published at http://wpftoolkit.codeplex.com/license 

   For more features, controls, and fast professional support,
   pick up the Plus Edition at http://xceed.com/wpf_toolkit

   Stay informed: follow @datagrid on Twitter or Like http://facebook.com/datagrids

  ***********************************************************************************/

using System;

namespace Xceed.Wpf.AvalonDock.Controls
{
  internal class FocusChangeEventArgs : EventArgs
  {
    #region Constructors

    public FocusChangeEventArgs( IntPtr gotFocusWinHandle, IntPtr lostFocusWinHandle )
    {
      GotFocusWinHandle = gotFocusWinHandle;
      LostFocusWinHandle = lostFocusWinHandle;
    }

    #endregion

    #region Properties

    public IntPtr GotFocusWinHandle
    {
      get;
      private set;
    }
    public IntPtr LostFocusWinHandle
    {
      get;
      private set;
    }

    #endregion
  }

  internal class WindowHookHandler
  {
    #region Members

    private IntPtr _windowHook;
    private Win32Helper.HookProc _hookProc;
    private ReentrantFlag _insideActivateEvent = new ReentrantFlag();

    #endregion

    #region Constructors

    public WindowHookHandler()
    {
    }

    #endregion

    #region Public Methods

    public void Attach()
    {
      _hookProc = new Win32Helper.HookProc( this.HookProc );
      _windowHook = Win32Helper.SetWindowsHookEx(
          Win32Helper.HookType.WH_CBT,
          _hookProc,
          IntPtr.Zero,
          ( int )Win32Helper.GetCurrentThreadId() );
    }

    public void Detach()
    {
      Win32Helper.UnhookWindowsHookEx( _windowHook );
    }

    public int HookProc( int code, IntPtr wParam, IntPtr lParam )
    {
      if( code == Win32Helper.HCBT_SETFOCUS )
      {
        if( FocusChanged != null )
          FocusChanged( this, new FocusChangeEventArgs( wParam, lParam ) );
      }
      else if( code == Win32Helper.HCBT_ACTIVATE )
      {
        if( _insideActivateEvent.CanEnter )
        {
          using( _insideActivateEvent.Enter() )
          {
            //if (Activate != null)
            //    Activate(this, new WindowActivateEventArgs(wParam));
          }
        }
      }


      return Win32Helper.CallNextHookEx( _windowHook, code, wParam, lParam );
    }

    #endregion

    #region Events

    public event EventHandler<FocusChangeEventArgs> FocusChanged;
    //public event EventHandler<WindowActivateEventArgs> Activate;

    #endregion
  }
}