wxluascript.cpp

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/***************************************************************
 * Name:      wxluascript.h
 * Purpose:   Defines a lua scripting object
 * Author:    Daniel Nell (daniel.nell@nellresearch.de)
 * Created:   2009-11-11
 * Copyright: Daniel Nell (www.nellresearch.de)
 * License:   wxWindows license
 **************************************************************/

// Include precompiled headers.
#include "wx_pch.h"

// wxWidgets headers
// ...

// Private header files.
#include "wxluascript.h"


/////////////////////////////////////////////////////////////////////////////
// Class wxLuaScript (scripting support)
//
// ...
//

#if __WXLUASCRIPT_DYNAMIC__
// Define dynamic library.
wxDynamicLibrary wxLuaScript::m_oWxLuaScriptDynamicLibrary;

// Define and initialize dynamic lua functions with NULL;
wxLuaScript::t_luaL_newstate *wxLuaScript::luaL_newstate= NULL;
wxLuaScript::t_luaL_openlibs *wxLuaScript::luaL_openlibs= NULL;
wxLuaScript::t_lua_atpanic *wxLuaScript::lua_atpanic= NULL;
wxLuaScript::t_lua_error *wxLuaScript::lua_error= NULL;
wxLuaScript::t_lua_gettop *wxLuaScript::lua_gettop= NULL;
wxLuaScript::t_luaL_loadstring *wxLuaScript::luaL_loadstring= NULL;
wxLuaScript::t_lua_pushstring *wxLuaScript::lua_pushstring= NULL;
wxLuaScript::t_lua_pushinteger *wxLuaScript::lua_pushinteger= NULL;
wxLuaScript::t_lua_pushboolean *wxLuaScript::lua_pushboolean= NULL;
wxLuaScript::t_lua_tointeger *wxLuaScript::lua_tointeger= NULL;
wxLuaScript::t_lua_tolstring *wxLuaScript::lua_tolstring= NULL;
wxLuaScript::t_lua_tonumber *wxLuaScript::lua_tonumber= NULL;
wxLuaScript::t_lua_toboolean *wxLuaScript::lua_toboolean= NULL;
wxLuaScript::t_lua_isnumber *wxLuaScript::lua_isnumber= NULL;
wxLuaScript::t_lua_type *wxLuaScript::lua_type= NULL;
wxLuaScript::t_lua_isstring *wxLuaScript::lua_isstring= NULL;
wxLuaScript::t_lua_pushcclosure *wxLuaScript::lua_pushcclosure= NULL;
wxLuaScript::t_lua_call *wxLuaScript::lua_call= NULL;
wxLuaScript::t_lua_pcall *wxLuaScript::lua_pcall= NULL;
wxLuaScript::t_lua_cpcall *wxLuaScript::lua_cpcall= NULL;
wxLuaScript::t_lua_settable *wxLuaScript::lua_settable= NULL;
wxLuaScript::t_lua_setfield *wxLuaScript::lua_setfield= NULL;
wxLuaScript::t_lua_getfield *wxLuaScript::lua_getfield= NULL;
wxLuaScript::t_lua_settop *wxLuaScript::lua_settop= NULL;
wxLuaScript::t_lua_insert *wxLuaScript::lua_insert= NULL;
wxLuaScript::t_lua_pushvalue *wxLuaScript::lua_pushvalue= NULL;
wxLuaScript::t_lua_close *wxLuaScript::lua_close= NULL;
wxLuaScript::t_lua_createtable *wxLuaScript::lua_createtable= NULL;
wxLuaScript::t_lua_pushlightuserdata *wxLuaScript::lua_pushlightuserdata= NULL;
wxLuaScript::t_lua_topointer *wxLuaScript::lua_topointer= NULL;
wxLuaScript::t_lua_gettable *wxLuaScript::lua_gettable= NULL;
wxLuaScript::t_lua_pushnumber *wxLuaScript::lua_pushnumber= NULL;
#endif // __WXLUASCRIPT_DYNAMIC__

// Standard constructor.
//
wxLuaScript::wxLuaScript( const wxString& strScript, wxEvtHandler *poParent,
                          const wxString& strDomain, bool *pbParentState )
#if __WXLUASCRIPT_DYNAMIC__
  : m_bOk( true )
#endif // __WXLUASCRIPT_DYNAMIC__
{
    // Initialize members.
    m_strScript= strScript;
    m_poParent= poParent;
    m_strDomain= strDomain;
    m_pbParentState= pbParentState;
    if( m_pbParentState )
    {
        (*m_pbParentState)= true;
    }

#if __WXLUASCRIPT_DYNAMIC__
    if( !m_oWxLuaScriptDynamicLibrary.IsLoaded() )
    {
        if( m_oWxLuaScriptDynamicLibrary.Load( wxDynamicLibrary::CanonicalizeName( wxT( WXLUASCRIPT_LIBLUA ) ),
                                               wxDL_DEFAULT | wxDL_GLOBAL ) )
        {
            luaL_newstate= (t_luaL_newstate *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "luaL_newstate" ) );
            luaL_openlibs= (t_luaL_openlibs *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "luaL_openlibs" ) );
            lua_atpanic= (t_lua_atpanic *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_atpanic" ) );
            lua_error= (t_lua_error *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_error" ) );
            lua_gettop= (t_lua_gettop *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_gettop" ) );
            luaL_loadstring= (t_luaL_loadstring *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "luaL_loadstring" ) );
            lua_pushstring= (t_lua_pushstring *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushstring" ) );
            lua_pushinteger= (t_lua_pushinteger *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushinteger" ) );
            lua_pushboolean= (t_lua_pushboolean *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushboolean" ) );
            lua_tointeger= (t_lua_tointeger *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_tointeger" ) );
            lua_tolstring= (t_lua_tolstring *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_tolstring" ) );
            lua_tonumber= (t_lua_tonumber *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_tonumber" ) );
            lua_toboolean= (t_lua_toboolean *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_toboolean" ) );
            lua_isnumber= (t_lua_isnumber *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_isnumber" ) );
            lua_type= (t_lua_type *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_type" ) );
            lua_isstring= (t_lua_isstring *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_isstring" ) );
            lua_pushcclosure= (t_lua_pushcclosure *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushcclosure" ) );
            lua_call= (t_lua_call *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_call" ) );
            lua_pcall= (t_lua_pcall *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pcall" ) );
            lua_cpcall= (t_lua_cpcall *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_cpcall" ) );
            lua_settable= (t_lua_settable *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_settable" ) );
            lua_setfield= (t_lua_setfield *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_setfield" ) );
            lua_getfield= (t_lua_getfield *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_getfield" ) );
            lua_settop= (t_lua_settop *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_settop" ) );
            lua_insert= (t_lua_insert *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_insert" ) );
            lua_pushvalue= (t_lua_pushvalue *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushvalue" ) );
            lua_close= (t_lua_close *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_close" ) );
            lua_createtable= (t_lua_createtable *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_createtable" ) );
            lua_pushlightuserdata= (t_lua_pushlightuserdata *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushlightuserdata" ) );
            lua_topointer= (t_lua_topointer *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_topointer" ) );
            lua_gettable= (t_lua_gettable *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_gettable" ) );
            lua_pushnumber= (t_lua_pushnumber *)m_oWxLuaScriptDynamicLibrary.GetSymbol( wxT( "lua_pushnumber" ) );
        }
        else
        {
            // Remember the state;
            m_bOk= false;

#if __DEBUG__
            // Log waring message in DEBUG mode.
            wxLogWarning( wxString( wxT( "wxLuaScript::wxLuaScript -- " ) )
                            + _( "Cannot load Lua library." ) );
#endif // __DEBUG__
            return;
        }
    }
#endif // __WXLUASCRIPT_DYNAMIC__

    // Initialize Lua.
    L= luaL_newstate();

    // Load Lua base libraries.
    luaL_openlibs( L );

    // Register an error handler (since there may be fatal Lua errors).
    lua_atpanic( L, LuaAtPanic );

    // Register the this pointer (to the current wxLuaScript object)
    // as a global value called "this".
    lua_pushinteger( L, (long)this );
    lua_setglobal( L, "this" );

    // Register "SendMenuEvent" as Lua function.
    RegisterFunction( wxT( "SendMenuEvent" ), SendMenuEvent );

    // Register "LogMessage" as Lua function.
    RegisterFunction( wxT( "LogMessage" ), LogMessage );
}

// Virtual destructor.
//
wxLuaScript::~wxLuaScript()
{
    // Cleanup Lua.
#if __WXLUASCRIPT_DYNAMIC__
    if( IsOk() )
    {
        lua_close( L );
    }
#else
    lua_close( L );
#endif // __WXLUASCRIPT_DYNAMIC__
}

// Register a new (LuaC-)function to Lua. (Lower level function.)
//
void wxLuaScript::RegisterFunction( lua_State* L, const char *pszTableName,
                                    const char * pszFuncName, lua_CFunction pLuaCFunction)
{
    lua_getfield( L, LUA_GLOBALSINDEX, pszTableName );          // push table onto stack
    if( !lua_istable( L, -1 ) )                                 // not a table, create it
    {
        lua_createtable( L, 0, 1 );                             // create new table
        lua_setfield( L, LUA_GLOBALSINDEX, pszTableName) ;      // add it to global context

                                                                // reset table on stack:
        lua_pop( L, 1 );                                        // pop table (nil value) from stack
        lua_getfield( L, LUA_GLOBALSINDEX, pszTableName );      // push table onto stack
    }

    lua_pushstring( L, pszFuncName );                           // push key onto stack
    lua_pushcfunction( L, pLuaCFunction );                      // push value onto stack
    lua_settable( L, -3 );                                      // add key-value pair to table

    lua_pop( L, 1 );                                            // pop table from stack
}

// Register new accessors for variables to Lua.
//
void wxLuaScript::RegisterVariable( const wxString& strLuaVarName, const int *pnValue )
{
    lua_gettable( L, LUA_GLOBALSINDEX );
    lua_pushlightuserdata( L, (void *)pnValue );
    lua_pushcclosure( L, wxLuaScript::LuaIntVarAccessor, 1 );
    lua_setfield( L, LUA_GLOBALSINDEX, strLuaVarName.char_str() );
}

int wxLuaScript::LuaIntVarAccessor( lua_State *L )
{
    int *p = (int *)lua_topointer( L, lua_upvalueindex( 1 ) );

    if( lua_gettop( L ) == 0 )
    {   // stack empty, so get
        lua_pushinteger( L, *p );
        return 1;
    }
    else
    {   // arg provided, so set
        *p = lua_tointeger( L, 1 );
        return 0;
    }
}

void wxLuaScript::RegisterVariable( const wxString& strLuaVarName, const bool *pnValue )
{
    lua_gettable( L, LUA_GLOBALSINDEX );
    lua_pushlightuserdata( L, (void *)pnValue );
    lua_pushcclosure( L, wxLuaScript::LuaBoolVarAccessor, 1 );
    lua_setfield( L, LUA_GLOBALSINDEX, strLuaVarName.char_str() );
}

int wxLuaScript::LuaBoolVarAccessor( lua_State *L )
{
    bool *p = (bool *)lua_topointer( L, lua_upvalueindex( 1 ) );

    if( lua_gettop( L ) == 0 )
    {   // stack empty, so get
        lua_pushboolean( L, *p );
        return 1;
    }
    else
    {   // arg provided, so set
        *p = lua_toboolean( L, 1 );
        return 0;
    }
}

void wxLuaScript::RegisterVariable( const wxString& strLuaVarName, const double *pnValue )
{
    lua_gettable( L, LUA_GLOBALSINDEX );
    lua_pushlightuserdata( L, (void *)pnValue );
    lua_pushcclosure( L, wxLuaScript::LuaDoubleVarAccessor, 1 );
    lua_setfield( L, LUA_GLOBALSINDEX, strLuaVarName.char_str() );
}

int wxLuaScript::LuaDoubleVarAccessor( lua_State *L )
{
    double *p = (double *)lua_topointer( L, lua_upvalueindex( 1 ) );

    if( lua_gettop( L ) == 0 )
    {   // stack empty, so get
        lua_pushnumber( L, *p );
        return 1;
    }
    else
    {   // arg provided, so set
        *p = (double)lua_tonumber( L, 1 );
        return 0;
    }
}

void wxLuaScript::RegisterVariable( const wxString& strLuaVarName, const wxString *pstrValue )
{
    lua_gettable( L, LUA_GLOBALSINDEX );
    lua_pushlightuserdata( L, (void *)pstrValue );
    lua_pushcclosure( L, wxLuaScript::LuaStringVarAccessor, 1 );
    lua_setfield( L, LUA_GLOBALSINDEX, strLuaVarName.char_str() );
}

int wxLuaScript::LuaStringVarAccessor( lua_State *L )
{
    wxString *p = (wxString *)lua_topointer( L, lua_upvalueindex( 1 ) );

    if( lua_gettop( L ) == 0 )
    {   // stack empty, so get
        lua_pushstring( L, p->char_str( wxConvISO8859_1 ) );
        return 1;
    }
    else
    {   // arg provided, so set
        (*p)= wxString( lua_tostring( L, 1 ), wxConvISO8859_1 );
        return 0;
    }
}

// Get the this-pointer from Lua.
//
wxLuaScript *wxLuaScript::GetThis( lua_State* L )
{
    // Get the this-pointer from Lua.
    lua_getglobal( L, "this" );
    return (wxLuaScript *)lua_tointeger( L, -1 );
}

// Run the Lua script in memory in protected mode.
//
// Note: This function is already called by Lua.
//       Therefore we can get error context, too.
//
int wxLuaScript::Run( lua_State* L )
{
    // Get the this-pointer to the current wxLuaScript object.
    wxLuaScript *poThis= GetThis( L );

    if( luaL_loadstring( L, poThis->m_strScript.char_str() ) )
    {
        // Log an error message.
        wxLogError( wxString( wxT( "int wxLuaScript::Run( lua_State* L ) -- " ) )
                      + _( "Cannot initialize Lua script." ) );

        // Return the number of (Lua) results.
        return 0;
    }

    // Insert TraceBack function.
    int base= lua_gettop(L);                            /* function index */
    lua_pushcfunction( L, wxLuaScript::TraceBack );     /* push traceback function */
    lua_insert( L, base );                              /* put it under chunk and args */

    // Run the script (from memory) and output an error
    // message if there was an error running the script.
    if( lua_pcall( L, 0, 0, base )
        && !lua_isnil( L, -1 ) )
    {
        // Get the error message and log it.
        wxLogError( wxString( (const char *)lua_tostring( L, -1 ), wxConvISO8859_1 ) );
    }

    // Return the number of (Lua) results.
    return 0;
}

// Create a stack trace on the Lua stack.
//
int wxLuaScript::TraceBack( lua_State* L )
{
    if( !lua_isstring(L, 1) )  /* 'message' not a string? */
    {
        return 1;  /* keep it intact */
    }
    lua_getfield(L, LUA_GLOBALSINDEX, "debug");
    if( !lua_istable( L, -1 ) )
    {
        lua_pop( L, 1 );
        return 1;
    }
    lua_getfield( L, -1, "traceback" );
    if( !lua_isfunction( L, -1 ) )
    {
        lua_pop( L, 2 );
        return 1;
    }
    lua_pushvalue( L, 1 );  /* pass error message */
    lua_pushinteger( L, 2 );  /* skip this function and traceback */
    lua_call( L, 2, 1 );  /* call debug.traceback */
    return 1;
}

// Error handler for (maybe fatal) Lua errors.
//
int wxLuaScript::LuaAtPanic( lua_State* L )
{
    // Get the error message and log it.
    wxLogError( wxString( (const char *)lua_tostring( L, 1 ), wxConvISO8859_1 ) );

    // Return the number of (Lua) results.
    return 0;
}

// Log a message on the standard wxWidgets log target.
//
// Note: You can change the standard log target and the
//       messages you log are logged to the new target, too.
//
int wxLuaScript::LogMessage( lua_State* L )
{
    // Check the number of argument(s) and the type(s).
    if( ( lua_gettop( L ) != 1 ) || !lua_isstring( L, 1 ) )
    {
        // Signal error.
        lua_pushstring( L, "Incorrect argument or incorrect number of arguments." );
        lua_error( L );
    }

    // Get the message and log it.
    wxLogMessage( wxString( (const char *)lua_tostring( L, 1 ), wxConvISO8859_1 ) );

    // Return the number of (Lua) results.
    return 0;
}

// Send a menu event to the parent event handler.
//
int wxLuaScript::SendMenuEvent( lua_State* L )
{
    // Check the number of (Lua) argument(s) and the type(s).
    if( ( lua_gettop( L ) != 1 ) || !lua_isnumber( L, 1 ) )
    {
        // Signal error.
        lua_pushstring( L, "Incorrect argument or incorrect number of arguments." );
        lua_error( L );
    }

    // Get the this pointer to the current wxLuaScript object.
    wxLuaScript *poThis= GetThis( L );

    // Get the pointer to the event handler.
    wxEvtHandler *poParent= poThis->m_poParent;

    // Post the message (if possible).
    if( poParent )
    {
        // Process the corresponding wxWidgets menu event.
        //
        // NOTE: We get the adress of the this-pointer from Lua
        //       (for this is a static function, and we need it
        //       to call the correct event handler).
        wxCommandEvent oEvent( wxEVT_COMMAND_MENU_SELECTED, lua_tonumber( L, 1 ) );

        if( poParent->ProcessEvent( oEvent ) )
        {
            // Push the return value ( the parent state );
            if( poThis->m_pbParentState )
            {
                lua_pushboolean( L, *poThis->m_pbParentState );
                (*poThis->m_pbParentState)= true;
            }
            else
            {
                lua_pushboolean( L, true );
            }
        }
        else
        {
            // Push an error value for the event could not be handled
            // or a proper event handler could not be found.
#if __DEBUG__
            wxLogWarning( wxT( "wxLuaScript::SendMenuEvent -- Could not handle the event." ) );
#endif
            lua_pushboolean( L, false );
        }
    }
    else
    {
        // Push an error value for there is no parent to post the
        // message.
        lua_pushboolean( L, false );
    }

    // Return the number of (Lua) results.
    return 1;
}