moLuaBase.h

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

                               moLuaBase.h

  ****************************************************************************
  *                                                                          *
  *   This source 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.                                    *
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  *   This code 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.                               *
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  *   A copy of the GNU General Public License is available on the World     *
  *   Wide Web at <http://www.gnu.org/copyleft/gpl.html>. You can also       *
  *   obtain it by writing to the Free Software Foundation,                  *
  *   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.         *
  *                                                                          *
  ****************************************************************************

  Copyright (C) 2006 Fabricio Costa

  Authors:
  Fabricio Costa
  Andrés Colubri

  Description:
  Classes for Lua scripting. Based in the Lua article and VC project by Richard
  Shephard, available online at:
  http://www.codeproject.com/cpp/luaincpp.asp?msg=1741798

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

#ifndef __MO_LUA_BASE_H__
#define __MO_LUA_BASE_H__

#include "moTypes.h"
#include "moAbstract.h"
#include "moText.h"

// LUA includes.
extern "C"
{
   #include <lua.h>
   #include <lauxlib.h>
   #include <lualib.h>
}

enum
{
   DBG_MASK_CALL = LUA_MASKCALL,
   DBG_MASK_RET = LUA_MASKRET,
   DBG_MASK_LINE = LUA_MASKLINE,
   DBG_MASK_COUNT = LUA_MASKCOUNT
};

class moLuaDebugger;

class LIBMOLDEO_API moLuaVirtualMachine
{
public:
    moLuaVirtualMachine (void);
    virtual ~moLuaVirtualMachine (void);

    bool InitialiseVM (void);
    bool FinaliseVM (void);

    bool RunFile (const char *strFilename);

    bool RunBuffer (const unsigned char *pbBuffer, size_t szLen, const char *strName = NULL);

    bool CallFunction (int nArgs, int nReturns = 0);

    operator lua_State *(void) { return m_pState; }

    static void Panic (lua_State *lua);

    virtual bool Ok (void) { return m_fIsOk; }

    void AttachDebugger (moLuaDebugger *dbg) { m_pDbg = dbg; }
protected:
   lua_State *m_pState;
   bool m_fIsOk;
   moLuaDebugger *m_pDbg;
};

class LIBMOLDEO_API moLuaDebugger : public moAbstract
{
public:
    moLuaDebugger (moLuaVirtualMachine& vm);
    virtual ~moLuaDebugger (void);

    void InitaliseDBG();
    void FinaliseDBG (void);

    void SetHooksFlag (int iMask);
    void SetCount (int iCount) { m_iCountMask = iCount; }

    void ErrorRun (int iErrorCode);
protected:
   int m_iCountMask;
   moLuaVirtualMachine& m_vm;
};


class LIBMOLDEO_API moLuaRestoreStack
{
public:
    moLuaRestoreStack (moLuaVirtualMachine& vm) : m_pState (NULL)
    {
       m_pState = (lua_State *) vm;
       if (vm.Ok ())
       {
          if (m_pState)
            m_iTop = lua_gettop (m_pState);
       }
    }

    virtual ~moLuaRestoreStack (void)
    {
       if (m_pState)
            lua_settop (m_pState, m_iTop);
    }
protected:
   lua_State *m_pState;
   int m_iTop;
};

class LIBMOLDEO_API moLuaThis
{
public:
    moLuaThis (moLuaVirtualMachine& vm, int iRef) : m_iOldRef (0), m_vm (vm)
    {
      lua_State *state = (lua_State *) vm;
      if (vm.Ok ())
      {
         // Save the old "this" table
         lua_getglobal (state, "this");
         m_iOldRef = luaL_ref (state, LUA_REGISTRYINDEX);

         // replace it with our new one
         lua_rawgeti(state, LUA_REGISTRYINDEX, iRef);
         lua_setglobal (state, "this");
      }
    }

    virtual ~moLuaThis (void)
    {
      lua_State *state = (lua_State *) m_vm;
      if (m_iOldRef > 0 && m_vm.Ok ())
      {
         // Replace the old "this" table
         lua_rawgeti(state, LUA_REGISTRYINDEX, m_iOldRef);
         lua_setglobal (state, "this");
         luaL_unref (state, LUA_REGISTRYINDEX, m_iOldRef);
      }
    }
protected:
   int m_iOldRef;
   moLuaVirtualMachine& m_vm;
};

#endif