/******************************************************************************
  MODULE: CHM_HELP.C
  PURPOSE: Gives context sensitive help using HtmlHelp CHM files
	   To display a particular topic, call the ChmHelp function of this module 
		 with the name of the html file to display
			Help("Topic.html");

		 For more help on building help files for Windows98, see:
		 http://msdn.microsoft.com/msdn-online/workshop/author/htmlhelp/
		 download and install the HtmlHelp Workshop. 

  IMPORTANT: the file HelpFile.chm must be in the same directory than the program
  NOTE: context sensitive help using constant numbers does not work
******************************************************************************/             
#include <Windows.h>		// (Or WinUser ?) Definitions for HtmlHelp.h
#include <userint.h>

#include "ChmHelp.h"

static char HelpFile[MAX_PATHNAME_LEN];
static BOOL MainHelpWindowIsOpen=FALSE;
static int WH=-1;
static int CallbackID=0;
static int WinMsgNum;
static char* ChmFile="HelpFile.chm";

// When is this called ?!?
static void HelpCallback(unsigned int wParam, unsigned lParam, void *callbackData) {
	Breakpoint();
}

/******************************************************************************
  FUNCTION: ChmHelp
  PURPOSE: Launch the Windows help with the appropriate context file
  IN: Context: name of the html file part of the chm file to display
  RETURN: FALSE on failure
******************************************************************************/
int ChmHelp(const char* Context) {
	HWND Ret;
	char File[MAX_PATHNAME_LEN];
	if (!MainHelpWindowIsOpen) {
		if (GetFullPathFromProject (ChmFile, HelpFile)==-1) {
			MessagePopup("Error !", "Unable to find file HelpFile.CHM in current directory.");
			return FALSE;
		}
		//if (Command==HELP_CONTEXTPOPUP) Command=HH_HELP_CONTEXT;
		WH=GetCVIWindowHandle ();
		WinMsgNum = RegisterWinMsgCallback (HelpCallback, NULL, 0, 0, &CallbackID, 1);
	    	MainHelpWindowIsOpen=TRUE;
	}
	
	strcpy(File, "mk:@MSITStore:");		// ??? Buggy without it
	strcat(File, HelpFile);
	strcat(File, "::/");
	strcat(File, Context);
	
	Ret=HtmlHelp((HWND)WH, /*Help*/File, HH_DISPLAY_TOPIC, 0/*(DWORD)File*/);
	return TRUE;
}

/******************************************************************************
  FUNCTION: QuitHelp
  PURPOSE: Should be called when quitting the main program. This will close the CHM window
******************************************************************************/
void QuitChmHelp(void) {
	HtmlHelp((HWND)WH, HelpFile, HH_CLOSE_ALL, 0);	// Closing the Help window
	if (CallbackID!=0) UnRegisterWinMsgCallback(CallbackID);
	//SystemHelp (HelpFile, HELP_QUIT, 0, 0);
	MainHelpWindowIsOpen=FALSE;
	WH=-1;
}