awesome/common/luaclass.h

/*
 * luaclass.h - useful functions for handling Lua classes
 *
 * Copyright © 2009 Julien Danjou <julien@danjou.info>
 *
 * This program 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#ifndef AWESOME_COMMON_LUACLASS
#define AWESOME_COMMON_LUACLASS

#include "common/signal.h"

typedef struct lua_class_property lua_class_property_t;

ARRAY_TYPE(lua_class_property_t, lua_class_property)

#define LUA_OBJECT_HEADER \
        signal_array_t signals;

/** Generic type for all objects.
 * All Lua objects can be casted to this type.
 */
typedef struct
{
    LUA_OBJECT_HEADER
} lua_object_t;

typedef lua_object_t *(*lua_class_allocator_t)(lua_State *);
typedef void (*lua_class_collector_t)(lua_object_t *);

typedef int (*lua_class_propfunc_t)(lua_State *, lua_object_t *);

typedef bool (*lua_class_checker_t)(lua_object_t *);

typedef struct lua_class_t lua_class_t;
struct lua_class_t
{
    /** Class name */
    const char *name;
    /** Class signals */
    signal_array_t signals;
    /** Parent class */
    lua_class_t *parent;
    /** Allocator for creating new objects of that class */
    lua_class_allocator_t allocator;
    /** Garbage collection function */
    lua_class_collector_t collector;
    /** Class properties */
    lua_class_property_array_t properties;
    /** Function to call when a indexing an unknown property */
    lua_class_propfunc_t index_miss_property;
    /** Function to call when a indexing an unknown property */
    lua_class_propfunc_t newindex_miss_property;
    /** Function to call to check if an object is valid */
    lua_class_checker_t checker;
    /** Number of instances of this class in lua */
    unsigned int instances;
};

const char * luaA_typename(lua_State *, int);
lua_class_t * luaA_class_get(lua_State *, int);

void luaA_class_connect_signal(lua_State *, lua_class_t *, const char *, lua_CFunction);
void luaA_class_connect_signal_from_stack(lua_State *, lua_class_t *, const char *, int);
void luaA_class_disconnect_signal_from_stack(lua_State *, lua_class_t *, const char *, int);
void luaA_class_emit_signal(lua_State *, lua_class_t *, const char *, int);

void luaA_openlib(lua_State *, const char *, const struct luaL_reg[], const struct luaL_reg[]);
void luaA_class_setup(lua_State *, lua_class_t *, const char *, lua_class_t *,
                      lua_class_allocator_t, lua_class_collector_t,
                      lua_class_checker_t,
                      lua_class_propfunc_t, lua_class_propfunc_t,
                      const struct luaL_reg[], const struct luaL_reg[]);

void luaA_class_add_property(lua_class_t *, const char *,
                             lua_class_propfunc_t, lua_class_propfunc_t, lua_class_propfunc_t);

int luaA_usemetatable(lua_State *, int, int);
int luaA_class_index(lua_State *);
int luaA_class_newindex(lua_State *);
int luaA_class_new(lua_State *, lua_class_t *);

void * luaA_checkudata(lua_State *, int, lua_class_t *);
void * luaA_toudata(lua_State *L, int ud, lua_class_t *);

static inline void *
luaA_checkudataornil(lua_State *L, int udx, lua_class_t *class)
{
    if(lua_isnil(L, udx))
        return NULL;
    return luaA_checkudata(L, udx, class);
}

#define LUA_CLASS_FUNCS(prefix, lua_class) \
    static inline int                                                          \
    luaA_##prefix##_class_add_signal(lua_State *L)                             \
    {                                                                          \
        signal_add(&(lua_class).signals, luaL_checkstring(L, 1));              \
        return 0;                                                              \
    }                                                                          \
                                                                               \
    static inline int                                                          \
    luaA_##prefix##_class_connect_signal(lua_State *L)                         \
    {                                                                          \
        luaA_class_connect_signal_from_stack(L, &(lua_class),                  \
                                             luaL_checkstring(L, 1), 2);       \
        return 0;                                                              \
    }                                                                          \
                                                                               \
    static inline int                                                          \
    luaA_##prefix##_class_disconnect_signal(lua_State *L)                      \
    {                                                                          \
        luaA_class_disconnect_signal_from_stack(L, &(lua_class),               \
                                                luaL_checkstring(L, 1), 2);    \
        return 0;                                                              \
    }                                                                          \
                                                                               \
    static inline int                                                          \
    luaA_##prefix##_class_emit_signal(lua_State *L)                            \
    {                                                                          \
        luaA_class_emit_signal(L, &(lua_class), luaL_checkstring(L, 1),        \
                               lua_gettop(L) - 1);                             \
        return 0;                                                              \
    }                                                                          \
                                                                               \
    static inline int                                                          \
    luaA_##prefix##_class_instances(lua_State *L)                              \
    {                                                                          \
        lua_pushnumber(L, (lua_class).instances);                              \
        return 1;                                                              \
    }

#define LUA_CLASS_METHODS(class) \
    { "add_signal", luaA_##class##_class_add_signal }, \
    { "connect_signal", luaA_##class##_class_connect_signal }, \
    { "disconnect_signal", luaA_##class##_class_disconnect_signal }, \
    { "emit_signal", luaA_##class##_class_emit_signal }, \
    { "instances", luaA_##class##_class_instances }, \

#define LUA_CLASS_META \
    { "__index", luaA_class_index }, \
    { "__newindex", luaA_class_newindex },

#endif

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