CDirectoryChangeWatcher - ReadDirectoryChangesW all wrapped up

// DelayedDirectoryChangeHandler.h: interface for the CDelayedDirectoryChangeHandler2 class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_DELAYEDDIRECTORYCHANGEHANDLER_H__F20EC22B_1C79_403E_B43C_938F95723D45__INCLUDED_)
#define AFX_DELAYEDDIRECTORYCHANGEHANDLER_H__F20EC22B_1C79_403E_B43C_938F95723D45__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CDirectoryChangeWatcher;
class CDirectoryChangeHandler;
class CDelayedDirectoryChangeHandler;

class CDelayedDirectoryChangeNotification
//
//	 A class to help dispatch the change notifications to the main thread.
//
{
private:
	CDelayedDirectoryChangeNotification();//not implemented
public:
	CDelayedDirectoryChangeNotification(CDelayedDirectoryChangeHandler * pDelayedHandler);
	~CDelayedDirectoryChangeNotification();

	//
	//
	void PostOn_FileAdded(const CString & strFileName);
	void PostOn_FileRemoved(const CString & strFileName);
	void PostOn_FileNameChanged(const CString & strOldName, const CString & strNewName);
	void PostOn_FileModified(const CString & strFileName);
	void PostOn_ReadDirectoryChangesError(DWORD dwError);

	void DispatchNotificationFunction();

protected:
	enum eFunctionToDispatch{	eFunctionNotDefined,
								eOn_FileAdded, 
								eOn_FileRemoved, 
								eOn_FileModified,
								eOn_FileRenamed,
								eOn_ReadDirectoryChangesError
	};	
	void PostNotification();
private:
	friend class CDelayedDirectoryChangeHandler;
	CDelayedDirectoryChangeHandler * m_pDelayedHandler;

	//
	//	Members to help implement DispatchNotificationFunction
	//
	//
	eFunctionToDispatch m_eFunctionToDispatch;
	CString	m_strFileName1,
			m_strFileName2;
	DWORD m_dwError;
};


//////////////////////////////////////////////////////////////////////////
//
//	This class makes it so that a file change notification is executed in the
//	context of the main thread, and not the worker thread.
//
//
//	It works by creating a hidden window.  When it receieves a notification
//	via one of the On_Filexxx() functions, a message is posted to this window.
//	when the message is handled, the notification is fired again in the context
//	of the main thread, or whichever thread that called CDirectoryChangeWatcher::WatchDirectory()
//
//

class CDelayedDirectoryChangeHandler : public CDirectoryChangeHandler
//	Helps all notifications become handled by the main
//	thread by posting messages to a window created in the main
//	thread.
//	Message is dispatched when message is handled by
//  that window.
//
//  The 'main' thread is the one that called CDirectoryChangeWatcher::WatchDirectory()
{
public:
	CDelayedDirectoryChangeHandler( CDirectoryChangeHandler * pRealHandler);
	~CDelayedDirectoryChangeHandler();
	
	
	CDirectoryChangeHandler * GetRealChangeHandler()const { return m_pRealHandler; }
	CDirectoryChangeHandler * & GetRealChangeHandler(){ return m_pRealHandler; }
protected:
	//These functions are called when the directory to watch has had a change made to it
	virtual void On_FileAdded(const CString & strFileName);
	virtual void On_FileRemoved(const CString & strFileName);
	virtual void On_FileModified(const CString & strFileName);
	virtual void On_FileNameChanged(const CString & strOldFileName, const CString & strNewFileName);
	virtual void On_ReadDirectoryChangesError(DWORD dwError);
	
	void SetChangedDirectoryName(const CString & strChangedDirName);
	const CString & GetChangedDirectoryName()const;
	void DispatchNotificationFunction(CDelayedDirectoryChangeNotification * pNotification);
	//
	//	A member class that controls a window to receive messages
	//
	class CDelayedNotificationWindow
		//
		//	No matter how many of these objects are,
		//	there will always be only one of the actual windows 
		//	in existance. (per thread that calls CDirectoryChangeWatcher::WatchDirectory())
		//
	{
	public:
		CDelayedNotificationWindow()
		{
			AddRef();
		}
		~CDelayedNotificationWindow(){
			Release();
		}
		
		void PostNotification(CDelayedDirectoryChangeNotification * pNotification);
	private:
		long AddRef();		//	the window handle is reference counted
		long Release();		//
		static long s_nRefCnt;
		static HWND s_hWnd;
		static BOOL s_bRegisterWindow;
		BOOL RegisterWindowClass(LPCTSTR szClassName);
		BOOL CreateNotificationWindow();
	};//end class CDelayedNotificationWindow
	friend class CDelayedDirectoryChangeNotification;
	friend class CDirectoryChangeWatcher;
	
	CDelayedNotificationWindow m_DelayWindow;
private:
		
	CDelayedDirectoryChangeNotification * GetNotificationObject();
	void DisposeOfNotification(CDelayedDirectoryChangeNotification * pNotification);
		
	CDirectoryChangeHandler * m_pRealHandler;	
};




#endif // !defined(AFX_DELAYEDDIRECTORYCHANGEHANDLER_H__F20EC22B_1C79_403E_B43C_938F95723D45__INCLUDED_)