//  Copyright (C) 2002 Ultr@VNC Team Members. All Rights Reserved.
//  Copyright (C) 2002 RealVNC Ltd. All Rights Reserved.
//  Copyright (C) 1997 AT&T Laboratories Cambridge. All Rights Reserved.
//
//  This file is part of the VNC system.
//
//  The VNC system is free software; you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation; either version 2 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program; if not, write to the Free Software
//  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
//  USA.
//
// If the source code for the VNC system is not available from the place 
// whence you received this file, check http://www.uk.research.att.com/vnc or contact
// the authors on vnc@uk.research.att.com for information on obtaining it.

// VNC update hook implementation.
//

#include "VNCHooks.h"

#include <stdlib.h>
#include <stdio.h>
#include <crtdbg.h>

/////////////////////////////////////////////////////////////////////////////
// Storage for the global data in the DLL

// MSVC is bugged - if a default value is missed off from one of the following
// variables then that variable is process-specific for some reason!

/////////////////////////////////////////////////////////////////////////////
// Storage for the global data in the DLL
// Note: For Borland C++ compilers, this data segment is defined in a
//       separate file, SharedData.cpp.

#ifdef _MSC_VER

// MSVC is bugged - if a default value is missed off from one of the following
// variables then that variable is process-specific for some reason!

#pragma data_seg(".SharedData")
DWORD vnc_thread_id = 0;
UINT UpdateRectMessage = 0;
UINT CopyRectMessage = 0;
UINT MouseMoveMessage = 0;
HHOOK hCallWndHook = NULL;							// Handle to the CallWnd hook
HHOOK hGetMsgHook = NULL;							// Handle to the GetMsg hook
HHOOK hDialogMsgHook = NULL;						// Handle to the DialogMsg hook
HHOOK hLLKeyboardHook = NULL;						// Handle to LowLevel kbd hook
HHOOK hLLMouseHook = NULL;							// Handle to LowLevel mouse hook
#pragma data_seg( )


#else

#include "SharedData.h"


#endif // _MSC_VER


/////////////////////////////////////////////////////////////////////////////
// Per-instance DLL variables

const char sPrefSegment[] = "Application_Prefs";
char *sModulePrefs = NULL;							// Name of the module that created us
BOOL prf_use_GetUpdateRect = FALSE;					// Use the GetUpdateRect paint mode
BOOL prf_use_Timer = FALSE;							// Use Timer events to trigger updates
BOOL prf_use_KeyPress = FALSE;						// Use keyboard events
BOOL prf_use_LButtonUp = TRUE;						// Use left mouse button up events
BOOL prf_use_MButtonUp = FALSE;						// Use middle mouse button up events
BOOL prf_use_RButtonUp = FALSE;						// Use right mouse button up events
BOOL prf_use_Deferral = FALSE;						// Use deferred updates

HINSTANCE hInstance = NULL;							// This instance of the DLL
BOOL HookMaster = FALSE;							// Is this instance WinVNC itself?

BOOL appHookedOK = FALSE;							// Did InitInstance succeed?

ULONG old_cursor = NULL;							// Current Cursor icon handle

BOOL m_ddihook;

/////////////////////////////////////////////////////////////////////////////
// Registered messages & atoms to be used by VNCHooks.DLL

// Messages
const UINT VNC_DEFERRED_UPDATE = RegisterWindowMessage("VNCHooks.Deferred.UpdateMessage");

// Atoms
const char *VNC_POPUPSELN_ATOMNAME = "VNCHooks.PopUpMenu.Selected";
ATOM VNC_POPUPSELN_ATOM = NULL;

/////////////////////////////////////////////////////////////////////////////
// The DLL functions

// Forward definition of hook procedures

BOOL HookHandle(UINT msg, HWND hWnd, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK CallWndProc (int nCode, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK GetMessageProc(int nCode, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK DialogMessageProc(int nCode, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK LowLevelKeyboardFilterProc(int nCode, WPARAM wParam, LPARAM lParam);
LRESULT CALLBACK LowLevelMouseFilterProc(int nCode, WPARAM wParam, LPARAM lParam);

// Forward definition of setup and shutdown procedures
BOOL InitInstance();
BOOL ExitInstance();

// The DLL's main procedure
BOOL WINAPI DllMain (HANDLE hInst, ULONG ul_reason_for_call, LPVOID lpReserved)
{
	// Find out why we're being called
	switch (ul_reason_for_call)
	{

	case DLL_PROCESS_ATTACH:
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : Hook DLL loaded\n");
#endif

		// Save the instance handle
		hInstance = (HINSTANCE)hInst;

		// Call the initialisation function
		appHookedOK = InitInstance();

		// ALWAYS return TRUE to avoid breaking unhookable applications!!!
		return TRUE;

	case DLL_PROCESS_DETACH:
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : Hook DLL unloaded\n");
#endif
		
		// Call the exit function
		// If the app failed to hook OK, ExitInstance will still operate OK (hopefully...)
		ExitInstance();

		return TRUE;

	default:
		return TRUE;
	}
}

// Function used to find out whether VNCHooks uses "reliable" or "hint" hooks
// Currently is always zero to indicate unreliable, hint hooks.
DllExport DWORD HooksType()
{
	// Unreliable "hint" hooks
	return 0;
}

// Add the new hook

DllExport BOOL SetHooks(DWORD thread_id, UINT UpdateMsg, UINT CopyMsg, UINT MouseMsg,BOOL ddihook)
{

	// Don't add the hook if the thread id is NULL
	if (!thread_id)
		return FALSE;
	m_ddihook=ddihook;
	
	// Don't add a hook if there is already one added
	if (vnc_thread_id)
		return FALSE;
	// Add the CallWnd hook
	hCallWndHook = SetWindowsHookEx(
					WH_CALLWNDPROC,					// Hook in before msg reaches app
					(HOOKPROC) CallWndProc,			// Hook procedure
					hInstance,						// This DLL instance
					0L								// Hook in to all apps
//					GetCurrentThreadId()			// DEBUG : HOOK ONLY WinVNC
					);

	// Add the GetMessage hook
	hGetMsgHook = SetWindowsHookEx(
					WH_GETMESSAGE,					// Hook in before msg reaches app
					(HOOKPROC) GetMessageProc,			// Hook procedure
					hInstance,						// This DLL instance
					0L								// Hook in to all apps
//					GetCurrentThreadId()			// DEBUG : HOOK ONLY WinVNC
					);

		// Add the GetMessage hook
	hDialogMsgHook = SetWindowsHookEx(
					WH_SYSMSGFILTER,				// Hook in dialogs, menus and scrollbars
					(HOOKPROC) DialogMessageProc,	// Hook procedure
					hInstance,						// This DLL instance
					0L								// Hook in to all apps
					);

	// Check that it worked
	if ((hCallWndHook != NULL) && (hGetMsgHook != NULL) && (hDialogMsgHook != NULL))
	{
		vnc_thread_id = thread_id;			// Save the WinVNC thread id
		UpdateRectMessage = UpdateMsg;		// Save the message ID to use for rectangle updates
		CopyRectMessage = CopyMsg;			// Save the message ID to use for copyrect
		MouseMoveMessage = MouseMsg;		// Save the message ID to send when mouse moves
		HookMaster = TRUE;					// Set the HookMaster flag for this instance
		return TRUE;
	}
	else
	{
		// Stop the keyboard hook
		SetKeyboardFilterHook(FALSE);
		SetMouseFilterHook(FALSE);

		// Kill the main hooks
		if (hCallWndHook != NULL)
			UnhookWindowsHookEx(hCallWndHook);
		if (hGetMsgHook != NULL)
			UnhookWindowsHookEx(hGetMsgHook);
		if (hDialogMsgHook != NULL)
			UnhookWindowsHookEx(hDialogMsgHook);
		hCallWndHook = NULL;
		hGetMsgHook = NULL;
		hDialogMsgHook = NULL;
	}
	if (ddihook)
	{
		if (hCallWndHook != NULL)
			UnhookWindowsHookEx(hCallWndHook);
		if (hDialogMsgHook != NULL)
			UnhookWindowsHookEx(hDialogMsgHook);
		hCallWndHook = NULL;
		hDialogMsgHook = NULL;
	}
	// The hook failed, so return an error code
	return FALSE;

}

// EnumWindows procedure to remove the extra property we added

BOOL CALLBACK
KillPropsProc(HWND hwnd, LPARAM lParam)
{
	// Remove our custom property...
	RemoveProp(hwnd, (LPCTSTR) MAKELONG(VNC_POPUPSELN_ATOM, 0));
	return TRUE;
}

// Remove the hook from the system

DllExport BOOL UnSetHooks(DWORD thread_id)
{

	BOOL unHooked = TRUE;
	
	// Remove the extra property value from all local windows
	EnumWindows((WNDENUMPROC) &KillPropsProc, NULL);

	// Stop the keyboard & mouse hooks
	unHooked = unHooked && SetKeyboardFilterHook(FALSE);
	unHooked = unHooked && SetMouseFilterHook(FALSE);

	// Is the window handle valid?
	if (thread_id != vnc_thread_id)
		return FALSE;

	// Unhook the procs
	if (hCallWndHook != NULL)
	{
		unHooked = unHooked && UnhookWindowsHookEx(hCallWndHook);
		hCallWndHook = NULL;
	}

	if (hGetMsgHook != NULL)
	{
		unHooked = unHooked && UnhookWindowsHookEx(hGetMsgHook);
		hGetMsgHook = NULL;
	}

	if (hDialogMsgHook != NULL)
	{
		unHooked = unHooked && UnhookWindowsHookEx(hDialogMsgHook);
		hDialogMsgHook = NULL;
	}

	// If we managed to unhook then reset
	if (unHooked)
	{
		vnc_thread_id = 0;
		HookMaster = FALSE;
	}

	return unHooked;

}

// Routine to start and stop local keyboard message filtering
DllExport BOOL SetKeyboardFilterHook(BOOL activate)
{
	if (activate)
	{
#ifdef WH_KEYBOARD_LL
		if (hLLKeyboardHook == NULL)
		{
			// Start up the hook...
			hLLKeyboardHook = SetWindowsHookEx(
					WH_KEYBOARD_LL,					// Hook in before msg reaches app
					(HOOKPROC) LowLevelKeyboardFilterProc,			// Hook procedure
					hInstance,						// This DLL instance
					0L								// Hook in to all apps
					);
			if (hLLKeyboardHook == NULL)
				return FALSE;
		}
		return TRUE;
#else
#pragma message("warning:Low-Level Keyboard hook code omitted.")
		return FALSE;
#endif
	} else {
		if (hLLKeyboardHook != NULL)
		{
			// Stop the hook...
			if (!UnhookWindowsHookEx(hLLKeyboardHook))
				return FALSE;
			hLLKeyboardHook = NULL;
		}
		return TRUE;
	}
}

// Routine to start and stop local mouse message filtering
DllExport BOOL SetMouseFilterHook(BOOL activate)
{
	if (activate)
	{
#ifdef WH_MOUSE_LL
		if (hLLMouseHook == NULL)
		{
			// Start up the hook...
			hLLMouseHook = SetWindowsHookEx(
					WH_MOUSE_LL,					// Hook in before msg reaches app
					(HOOKPROC) LowLevelMouseFilterProc,			// Hook procedure
					hInstance,						// This DLL instance
					0L								// Hook in to all apps
					);
			if (hLLMouseHook == NULL)
				return FALSE;
		}
		return TRUE;
#else
#pragma message("warning:Low-Level Mouse hook code omitted.")
		return FALSE;
#endif
	} else {
		if (hLLMouseHook != NULL)
		{
			// Stop the hook...
			if (!UnhookWindowsHookEx(hLLMouseHook))
				return FALSE;
			hLLMouseHook = NULL;
		}
		return TRUE;
	}
}

// Routine to get the window's client rectangle, in screen coordinates
inline BOOL GetAbsoluteClientRect(HWND hwnd, RECT *rect)
{
	POINT topleft;
	topleft.x = 0;
	topleft.y = 0;

	// Get the client rectangle size
	if (!GetClientRect(hwnd, rect))
		return FALSE;

	// Get the client rectangle position
	if (!ClientToScreen(hwnd, &topleft))
		return FALSE;

	// Now adjust the window rectangle
	rect->left += topleft.x;
	rect->top += topleft.y;
	rect->right += topleft.x;
	rect->bottom += topleft.y;

	return TRUE;
}

// Routine to send an UpdateRect message to WinVNC
inline void SendUpdateRect(SHORT x, SHORT y, SHORT x2, SHORT y2)
{
	WPARAM vwParam;
	LPARAM vlParam;

	vwParam = MAKELONG(x, y);
	vlParam = MAKELONG(x2, y2);

	// Send the update to WinVNC
	PostThreadMessage(
		vnc_thread_id,
		UpdateRectMessage,
		vwParam,
		vlParam
		);
	HWND hWndRemote=FindWindow("WinVNC desktop sink", "WinVNC");
	if (hWndRemote==NULL) UnSetHooks(vnc_thread_id);
}

// Send a window's position to WinVNC

inline void SendWindowRect(HWND hWnd)
{
	RECT wrect;

	// Get the rectangle position
	if (IsWindowVisible(hWnd) && GetWindowRect(hWnd, &wrect))
	{
		// Send the position
		SendUpdateRect(
			(SHORT) wrect.left,
			(SHORT) wrect.top,
			(SHORT) wrect.right,
			(SHORT) wrect.bottom
			);
	}
}

// Send a deferred message into this Window's message queue, so that
// we'll intercept it again only after the message that triggered it has been
// handled

inline void SendDeferredUpdateRect(HWND hWnd, SHORT x, SHORT y, SHORT x2, SHORT y2)
{
	WPARAM vwParam;
	LPARAM vlParam;

	vwParam = MAKELONG(x, y);
	vlParam = MAKELONG(x2, y2);

	if (prf_use_Deferral)
	{
		// Send the update back to the window
		PostMessage(
			hWnd,
			VNC_DEFERRED_UPDATE,
			vwParam,
			vlParam
			);
	}
	else
	{
		// Send the update to WinVNC
		PostThreadMessage(
			vnc_thread_id,
			UpdateRectMessage,
			vwParam,
			vlParam
			);
	}
}

inline void SendDeferredWindowRect(HWND hWnd)
{
	RECT wrect;

	// Get the rectangle position
	if (IsWindowVisible(hWnd) && GetWindowRect(hWnd, &wrect))
	{
		// Send the position
		SendDeferredUpdateRect(
			hWnd,
			(SHORT) wrect.left,
			(SHORT) wrect.top,
			(SHORT) wrect.right,
			(SHORT) wrect.bottom
			);
	}
}

inline void SendDeferredBorderRect(HWND hWnd)
{
	RECT wrect;
	RECT crect;

	// Get the rectangle position
	if (IsWindowVisible(hWnd) && GetWindowRect(hWnd, &wrect))
	{
		// Get the client rectangle position
		if (GetAbsoluteClientRect(hWnd, &crect))
		{
			// Send the four border rectangles
			SendDeferredUpdateRect(hWnd, (SHORT) wrect.left, (SHORT) wrect.top, (SHORT) wrect.right, (SHORT) crect.top);
			SendDeferredUpdateRect(hWnd, (SHORT) wrect.left, (SHORT) wrect.top, (SHORT) crect.left, (SHORT) wrect.bottom);
			SendDeferredUpdateRect(hWnd, (SHORT) wrect.left, (SHORT) crect.bottom, (SHORT) wrect.right, (SHORT) wrect.bottom);
			SendDeferredUpdateRect(hWnd, (SHORT) crect.right, (SHORT) wrect.top, (SHORT) wrect.right, (SHORT) wrect.bottom);
		}
	}
}
// ddihook, we only need the mouse info
inline BOOL HookHandleddi(UINT MessageId, HWND hWnd, WPARAM wParam, LPARAM lParam)
{
	switch (MessageId)
	{
	case WM_NCMOUSEMOVE:
	case WM_MOUSEMOVE:
		// Inform WinVNC that the mouse has moved and pass it the current cursor handle
		{
			ULONG new_cursor = (ULONG)GetCursor();
			if (new_cursor != old_cursor) {
				PostThreadMessage(
					vnc_thread_id,
					MouseMoveMessage,
					(ULONG) new_cursor, 0);
				old_cursor=new_cursor;
			}
		}
		break;
	}
	return TRUE;
}
// Generic hook-handler

inline BOOL HookHandle(UINT MessageId, HWND hWnd, WPARAM wParam, LPARAM lParam)
{
	////////////////////////////////////////////////////////////////
	// HANDLE DEFERRED UPDATES

	// Is this a deferred-update message?
	if (MessageId == VNC_DEFERRED_UPDATE)
	{

		// NOTE : NEVER use the SendDeferred- routines to send updates
		//		from here, or you'll get an infinite loop....!

		// NB : The format of DEFERRED_UPDATE matches that of UpdateRectMessage,
		//		so just send the exact same message data to WinVNC

		PostThreadMessage(
			vnc_thread_id,
			UpdateRectMessage,
			wParam,
			lParam
			);

		return FALSE;
	}

	// *** Could use WM_COPYDATA to send data to WinVNC

/*
	if (GetClassLong(hWnd, GCW_ATOM) == 32768)
	{
		_RPT4(_CRT_WARN, "DBG : popup menu message (hwnd=%d, msg=%d, l=%d, w=%d)\n",
		hWnd, MessageId, lParam, wParam);
	}
*/

	////////////////////////////////////////////////////////////////
	// UPDATE-TRIGGERING MESSAGES

	// Do something dependent upon message type
	switch (MessageId)
	{
		
		////////////////////////////////////////////////////////////////
		// Messages indicating only a border repaint.
	case WM_NCPAINT:
	case WM_NCACTIVATE:
		SendDeferredBorderRect(hWnd);
		old_cursor = NULL;
		break;

		////////////////////////////////////////////////////////////////
		// Messages indicating a client area repaint
	case WM_CHAR:
	case WM_KEYUP:							// Handle key-presses
		if (prf_use_KeyPress)
			SendDeferredWindowRect(hWnd);
		break;

	case WM_LBUTTONUP:						// Handle LMB clicks
		if (prf_use_LButtonUp)
			SendDeferredWindowRect(hWnd);
		break;

	case WM_MBUTTONUP:						// Handle MMB clicks
		if (prf_use_MButtonUp)
			SendDeferredWindowRect(hWnd);
		break;

	case WM_RBUTTONUP:						// Handle RMB clicks
		if (prf_use_RButtonUp)
			SendDeferredWindowRect(hWnd);
		break;

	case WM_TIMER:
		if (prf_use_Timer)
			SendDeferredWindowRect(hWnd);
		break;

	case WM_HSCROLL:
	case WM_VSCROLL:
		if (((int) LOWORD(wParam) == SB_THUMBTRACK) || ((int) LOWORD(wParam) == SB_ENDSCROLL))
			SendDeferredWindowRect(hWnd);
		break;

	case 485:  // HACK to handle popup menus
		{
			// Get the old popup menu selection value
			HANDLE prop = GetProp(hWnd, (LPCTSTR) MAKELONG(VNC_POPUPSELN_ATOM, 0));
			if (prop != (HANDLE) wParam)
			{
				// It did, so update the menu & the selection value
				SendDeferredWindowRect(hWnd);
				SetProp(hWnd,
					(LPCTSTR) MAKELONG(VNC_POPUPSELN_ATOM, 0),
					(HANDLE) wParam);
			}
		}
		break;

		////////////////////////////////////////////////////////////////
		// Messages indicating a full window update
	case WM_SYSCOLORCHANGE:
	case WM_PALETTECHANGED:
	case WM_SETTEXT:
	case WM_ENABLE:
	case BM_SETCHECK:
	case BM_SETSTATE:
	case EM_SETSEL:
	//case WM_MENUSELECT:
		SendDeferredWindowRect(hWnd);
		break;

		////////////////////////////////////////////////////////////////
		// Messages indicating that an area of the window needs updating
		// Uses GetUpdateRect to find out which
	case WM_PAINT:
		if (prf_use_GetUpdateRect)
		{
			HRGN region;
			region = CreateRectRgn(0, 0, 0, 0);

			// Get the affected region
			if (GetUpdateRgn(hWnd, region, FALSE) != ERROR)
			{
				int buffsize;
				UINT x;
				RGNDATA *buff;
				POINT TopLeft;

				// Get the top-left point of the client area
				TopLeft.x = 0;
				TopLeft.y = 0;
				if (!ClientToScreen(hWnd, &TopLeft))
					break;

				// Get the size of buffer required
				buffsize = GetRegionData(region, 0, 0);
				if (buffsize != 0)
				{
					buff = (RGNDATA *) new BYTE [buffsize];
					if (buff == NULL)
						break;

					// Now get the region data
					if(GetRegionData(region, buffsize, buff))
					{
						for (x=0; x<(buff->rdh.nCount); x++)
						{
							// Obtain the rectangles from the list
							RECT *urect = (RECT *) (((BYTE *) buff) + sizeof(RGNDATAHEADER) + (x * sizeof(RECT)));
							SendDeferredUpdateRect(
								hWnd,
								(SHORT) (TopLeft.x + urect->left),
								(SHORT) (TopLeft.y + urect->top),
								(SHORT) (TopLeft.x + urect->right),
								(SHORT) (TopLeft.y + urect->bottom)
								);

							// Modified by mws for VNC ver. 3.3.6
							// We yield this thread so our PostMessages and socket commands
							// can complete, otherwise this hook can suck up too many
							// timeslices before it returns
							Sleep (0);
						}
					}

					delete [] buff;
				}
			}

			// Now free the region
			if (region != NULL)
				DeleteObject(region);
		}
		else
			SendDeferredWindowRect(hWnd);
		break;

		////////////////////////////////////////////////////////////////
		// Messages indicating full repaint of this and a different window
		// Send the new position of the window
	case WM_WINDOWPOSCHANGING:
		if (IsWindowVisible(hWnd))
			SendWindowRect(hWnd);
		break;

	case WM_WINDOWPOSCHANGED:
		if (IsWindowVisible(hWnd))
			SendDeferredWindowRect(hWnd);
		break;

	////////////////////////////////////////////////////////////////
	// WinVNC also wants to know about mouse movement
	case WM_NCMOUSEMOVE:
	case WM_MOUSEMOVE:
		// Inform WinVNC that the mouse has moved and pass it the current cursor handle
		{
			ULONG new_cursor = (ULONG)GetCursor();
			if (new_cursor != old_cursor) {
				PostThreadMessage(
					vnc_thread_id,
					MouseMoveMessage,
					(ULONG) new_cursor, 0);
				old_cursor=new_cursor;
			}
		}
		break;

    // RealVNC 335
    case WM_MOUSEWHEEL:           // Handle mousewheel events
       SendDeferredWindowRect(hWnd);
       break;
		////////////////////////////////////////////////////////////////
		// VNCHOOKS PROPERTIES HANDLING WINDOWS
	case WM_DESTROY:
		RemoveProp(hWnd, (LPCTSTR) MAKELONG(VNC_POPUPSELN_ATOM, 0));
		break;

	}

	return TRUE;
}

// Hook procedure for CallWindow hook

LRESULT CALLBACK CallWndProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	// Do we have to handle this message?
	if (nCode == HC_ACTION)
	{
		// Process the hook if the WinVNC thread ID is valid
		if (vnc_thread_id)
		{
			CWPSTRUCT *cwpStruct = (CWPSTRUCT *) lParam;
			HookHandle(cwpStruct->message, cwpStruct->hwnd, cwpStruct->wParam, cwpStruct->lParam);
		}
	}

	// Call the next handler in the chain
    return CallNextHookEx (hCallWndHook, nCode, wParam, lParam);
}

// Hook procedure for GetMessageProc hook

LRESULT CALLBACK GetMessageProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	// Do we have to handle this message?
	if (nCode == HC_ACTION)
	{
		// Process the hook only if the WinVNC thread id is valid
		if (vnc_thread_id)
		{
			MSG *msg = (MSG *) lParam;

			// Only handle application messages if they're being removed:
			if (wParam & PM_REMOVE)
			{
				// Handle the message
				if (m_ddihook)
				HookHandleddi(msg->message, msg->hwnd, msg->wParam, msg->lParam);
				else HookHandle(msg->message, msg->hwnd, msg->wParam, msg->lParam);
			}
		}
	}

	// Call the next handler in the chain
    return CallNextHookEx (hGetMsgHook, nCode, wParam, lParam);
}


// Hook procedure for DialogMessageProc hook

LRESULT CALLBACK DialogMessageProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	// Do we have to handle this message?
	if (nCode >= 0)
	{
		// Process the hook only if the WinVNC thread ID is valid
		if (vnc_thread_id)
		{
			MSG *msg = (MSG *) lParam;

			// Handle the message
			HookHandle(msg->message, msg->hwnd, msg->wParam, msg->lParam);
		}
	}

	// Call the next handler in the chain
    return CallNextHookEx (hGetMsgHook, nCode, wParam, lParam);
}

// Hook procedure for LowLevel Keyboard filtering

#ifdef WH_KEYBOARD_LL
LRESULT CALLBACK LowLevelKeyboardFilterProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	// Are we expected to handle this callback?
	if (nCode == HC_ACTION)
	{
		// Is this keyboard event "real" or "injected"
		// i.e. hardware or software-produced?
		KBDLLHOOKSTRUCT *hookStruct = (KBDLLHOOKSTRUCT*)lParam;
		if (!(hookStruct->flags & LLKHF_INJECTED)) {
			// Message was not injected - reject it!
			return TRUE;
		}
	}

	// Otherwise, pass on the message
	return CallNextHookEx(hLLKeyboardHook, nCode, wParam, lParam);
}
#endif

// Hook procedure for LowLevel Mouse filtering

#ifdef WH_MOUSE_LL
LRESULT CALLBACK LowLevelMouseFilterProc(int nCode, WPARAM wParam, LPARAM lParam)
{
	// Are we expected to handle this callback?
	if (nCode == HC_ACTION)
	{
		// Is this mouse event "real" or "injected"
		// i.e. hardware or software-produced?
		MSLLHOOKSTRUCT *hookStruct = (MSLLHOOKSTRUCT*)lParam;
		if (!(hookStruct->flags & LLMHF_INJECTED)) {
			// Message was not injected - reject it!
			return TRUE;
		}
	}

	// Otherwise, pass on the message
	return CallNextHookEx(hLLMouseHook, nCode, wParam, lParam);
}
#endif

char * NameFromPath(const char *path)
{
	int x;
	int l = strlen(path);
	char *temp = NULL;
	
	// Find the file part of a filename
	for (x=l-1; x>0; x--)
	{
		if (path[x] == '\\')
		{
			temp = _strdup(&(path[x+1]));
			break;
		}
	}

	// If we didn't fine a \ then just return a copy of the original
	if (temp == NULL)
		temp = _strdup(path);

	return temp;
}

/////////////////////////////////////////////////////////////////////////////
// Initialise / Exit routines.
// These functions handle the update settings for any apps used with WinVNC.

static const TCHAR szSoftware[] = "Software";
static const TCHAR szCompany[] = "ORL";
static const TCHAR szProfile[] = "VNCHooks";

HKEY hModuleKey = NULL;

HKEY OpenKey(HKEY basekey, const char* path[], bool writable, bool create) {
	HKEY key = basekey;
	DWORD flags = KEY_READ;
	if (writable) flags |= KEY_WRITE;
	if (create) flags |= KEY_CREATE_SUB_KEY;
	unsigned int i = 0;
	while (path[i]) {
		HKEY newkey;
		DWORD result, dw;
		if (create) {
#ifdef _MSC_VER 
			_RPT2(_CRT_WARN, "vncHooks : creating %s from %x\n", path[i], key);
#endif
			result = RegCreateKeyEx(key, path[i], 0, REG_NONE,
				REG_OPTION_NON_VOLATILE, flags, NULL,
				&newkey, &dw);
		} else {
#ifdef _MSC_VER 
			_RPT2(_CRT_WARN, "vncHooks : opening %s from %x\n", path[i], key);
#endif
			result = RegOpenKeyEx(key, path[i], 0, flags, &newkey);
		}
		if (key && (key != basekey)) RegCloseKey(key);
		key = newkey;
		if (result != ERROR_SUCCESS) {
#ifdef _MSC_VER 
			_RPT2(_CRT_WARN, "vncHooks : failed to open %s(%lu)\n", path[i], result);
#endif
			return NULL;
		} else {
#ifdef _MSC_VER 
			_RPT2(_CRT_WARN, "vncHooks : opened %s (%x)\n", path[i], key);
#endif
		}
		i++;
	}
	return key;
}

HKEY GetModuleKey(HKEY basekey, const char* proc_name, bool writable, bool create) {
	// Work out the registry key to save this under
	if (!sModulePrefs) {
		sModulePrefs = (char *) malloc(strlen(proc_name) + 1);
		if (sModulePrefs == NULL)
			return FALSE;
		strcpy(sModulePrefs, proc_name);
	}
	
	// Check whether the library's entry exists!
	const char* appPath[] = {szSoftware, szCompany, szProfile, 0};
	HKEY appKey = OpenKey(basekey, appPath, writable, create);
	if (!appKey)
		return NULL;
	
	// Attempt to open the registry section for the application
	const char* modPath[] = {sPrefSegment, sModulePrefs, 0};
	HKEY modKey = OpenKey(appKey, modPath, writable, false);
	if (!modKey) {
		// Cut off the app directory and just use the name
		char *file_name = NameFromPath(proc_name);
		
		if (!file_name)
		{
			RegCloseKey(appKey);
			return NULL;
		}
		
		// Adjust the moduleprefs name
		strcpy(sModulePrefs, file_name);
		free(file_name);
		
		// Now get the module key again
		const char* modPath2[] = {sPrefSegment, sModulePrefs, 0};
		modKey = OpenKey(appKey, modPath2, writable, create);
	}
	
	RegCloseKey(appKey);
	
	return modKey;
}

int GetProfileInt(LPTSTR key, int def)
{
	DWORD type;
	DWORD value;
	ULONG size = sizeof(value);

	if (RegQueryValueEx(
		hModuleKey,
		key,
		NULL,
		&type,
		(unsigned char *)&value,
		&size) == ERROR_SUCCESS)
	{
		// Is the value of the right type?
		if (type != REG_DWORD)
		{
			return def;
		}
		else
		{
			return value;
		}
	}
	else
	{
		return def;
	}
}

void WriteProfileInt(LPTSTR key, int value)
{
	RegSetValueEx(
		hModuleKey,
		key,
		0,
		REG_DWORD,
		(unsigned char *)&value,
		sizeof(value));
}

void ReadSettings() {
  // Read in the prefs
	prf_use_GetUpdateRect = GetProfileInt(
		"use_GetUpdateRect",
		TRUE
		);

	prf_use_Timer = GetProfileInt(
		"use_Timer",
		FALSE
		);
	prf_use_KeyPress = GetProfileInt(
		"use_KeyPress",
		TRUE
		);
	prf_use_LButtonUp = GetProfileInt(
		"use_LButtonUp",
		TRUE
		);
	prf_use_MButtonUp = GetProfileInt(
		"use_MButtonUp",
		TRUE
		);
	prf_use_RButtonUp = GetProfileInt(
		"use_RButtonUp",
		TRUE
		);
	prf_use_Deferral = GetProfileInt(
		"use_Deferral",
		TRUE
		);
}

BOOL InitInstance() 
{
	// Create the global atoms
	VNC_POPUPSELN_ATOM = GlobalAddAtom(VNC_POPUPSELN_ATOMNAME);
	if (VNC_POPUPSELN_ATOM == NULL)
		return FALSE;

	// Get the module name
	char proc_name[_MAX_PATH];
	DWORD size;

	// Attempt to get the program/module name
	if ((size = GetModuleFileName(
		GetModuleHandle(NULL),
		(char *) &proc_name,
		_MAX_PATH
		)) == 0)
		return FALSE;

  // Get the default system key for the module
	hModuleKey = GetModuleKey(HKEY_LOCAL_MACHINE, proc_name, false, false);
  if (hModuleKey != NULL) {
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : loading machine prefs\n");
#endif
    ReadSettings();
		RegCloseKey(hModuleKey);
    hModuleKey = NULL;
  }

	// Get the key for the module
	hModuleKey = GetModuleKey(HKEY_CURRENT_USER, proc_name, false, false);
  if (hModuleKey != NULL) {
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : loading user prefs\n");
#endif
    ReadSettings();
		RegCloseKey(hModuleKey);
    hModuleKey = NULL;
  }

	return TRUE;
}

BOOL ExitInstance() 
{
	// Free the created atoms
	if (VNC_POPUPSELN_ATOM != NULL)
	{
		// GlobalDeleteAtom(VNC_POPUPSELN_ATOM);
		VNC_POPUPSELN_ATOM = NULL;
	}

	// Write the module settings to disk
	if (sModulePrefs != NULL)
	{
	  // Get the module name
	  char proc_name[_MAX_PATH];
	  DWORD size;

	  // Attempt to get the program/module name
	  if ((size = GetModuleFileName(
		  GetModuleHandle(NULL),
		  (char *) &proc_name,
		  _MAX_PATH
		  )) == 0)
		  return FALSE;

	  // Get the key for the module
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : locating user prefs\n");
#endif
	  hModuleKey = GetModuleKey(HKEY_CURRENT_USER, proc_name, true, true);
	  if (hModuleKey == NULL)
		  return FALSE;
#ifdef _MSC_VER 
		_RPT0(_CRT_WARN, "vncHooks : writing user prefs\n");
#endif

		WriteProfileInt(
			"use_GetUpdateRect",
			prf_use_GetUpdateRect
			);

		WriteProfileInt(
			"use_Timer",
			prf_use_Timer
			);

		WriteProfileInt(
			"use_KeyPress",
			prf_use_KeyPress
			);

		WriteProfileInt(
			"use_LButtonUp",
			prf_use_LButtonUp
			);

		WriteProfileInt(
			"use_MButtonUp",
			prf_use_MButtonUp
			);

		WriteProfileInt(
			"use_RButtonUp",
			prf_use_RButtonUp
			);

		WriteProfileInt(
			"use_Deferral",
			prf_use_Deferral
			);

		free(sModulePrefs);
		sModulePrefs = NULL;
	}

	// Close the registry key for this module
  if (hModuleKey != NULL) {
		RegCloseKey(hModuleKey);
    hModuleKey = NULL;
  }

	return TRUE;
}
