Middle Mouse Button (or Wheel) to Doubleclick (VC6)

// MouseHook.cpp : Defines the entry point for the DLL application.
//

#include "stdafx.h"
#define _COMPILING_44E531B1_14D3_11d5_A025_006067718D04
#include "MouseHook.h"

#pragma data_seg(".JET")
HWND hWndServer = NULL;
#pragma data_seg()
#pragma comment(linker, "/section:.JET,rws")

HINSTANCE hInst;
UINT UWM_MBTNCLICK;
HHOOK hook;
static LRESULT CALLBACK msghook(UINT nCode, WPARAM wParam, LPARAM lParam);

BOOL APIENTRY DllMain( HINSTANCE hInstance, 
                       DWORD  Reason, 
                       LPVOID Reserved
					 )
{
 switch(Reason)
    { /* reason */
     case DLL_PROCESS_ATTACH:
	hInst = hInstance;
	UWM_MBTNCLICK = RegisterWindowMessage(UWM_MBTNCLICK_MSG);
	return TRUE;
     case DLL_PROCESS_DETACH:
	if(hWndServer != NULL)
	   clearMyHook(hWndServer);
	return TRUE;
    } /* reason */
    return TRUE;
}


/****************************************************************************
*                                 setMyHook
* Inputs:
*       HWND hWnd: Window to notify
* Result: BOOL
*       TRUE if successful
*	FALSE if error
* Effect: 
*       Sets the hook
****************************************************************************/

__declspec(dllexport) BOOL setMyHook(HWND hWnd) {
	if(hWndServer != NULL)
		return FALSE; // already hooked!
    
	hook = SetWindowsHookEx(WH_MOUSE_LL,
			    (HOOKPROC)msghook,
			    hInst,
			    0);
    if(hook != NULL) { /* success */
		hWndServer = hWnd;
		return TRUE;
	} /* success */
    return FALSE; // failed to set hook
} // setMyHook

/****************************************************************************
*                                 clearMyHook
* Inputs:
*       HWND hWnd: Window hook
* Result: BOOL
*       TRUE if successful
*	FALSE if error
* Effect: 
*       Removes the hook that has been set
****************************************************************************/

__declspec(dllexport) BOOL clearMyHook(HWND hWnd) {
	if(hWnd != hWndServer || hWnd == NULL)
		return FALSE;
    
	BOOL unhooked = UnhookWindowsHookEx(hook);
    
	if(unhooked)
		hWndServer = NULL;

    return unhooked;
} // clearMyHook

/****************************************************************************
*                                   msghook
* Inputs:
*       int nCode: Code value
*	WPARAM wParam:
*	LPARAM lParam:
* Result: LRESULT
*       Either 0 or the result of CallNextHookEx
* Effect: 
*       Hook processing function. If the message is a mouse-move message,
*	posts the coordinates to the parent window
****************************************************************************/

static LRESULT CALLBACK msghook(UINT nCode, WPARAM wParam, LPARAM lParam) {
	if(nCode < 0) { /* pass it on */
		CallNextHookEx(hook, nCode, wParam, lParam);
		return 0;
	} /* pass it on */

	if(wParam == WM_MBUTTONUP ){
		PostMessage(hWndServer, UWM_MBTNCLICK, 0, 0);
	}

    return CallNextHookEx(hook, nCode, wParam, lParam);
} // msghook