common/luaobject.h

   1 /*
   2  * luaobject.h - useful functions for handling Lua objects
   3  *
   4  * Copyright © 2009 Julien Danjou <julien@danjou.info>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #ifndef AWESOME_COMMON_LUAOBJECT
  23 #define AWESOME_COMMON_LUAOBJECT
  24
  25 #include "common/luaclass.h"
  26
  27 #define LUAA_OBJECT_REGISTRY_KEY "awesome.object.registry"
  28
  29 int luaA_settype(lua_State *, lua_class_t *);
  30 void luaA_object_setup(lua_State *);
  31 void * luaA_object_incref(lua_State *, int, int);
  32 void luaA_object_decref(lua_State *, int, void *);
  33
  34 /** Store an item in the environment table of an object.
  35  * \param L The Lua VM state.
  36  * \param ud The index of the object on the stack.
  37  * \param iud The index of the item on the stack.
  38  * \return The item reference.
  39  */
  40 static inline void *
  41 luaA_object_ref_item(lua_State *L, int ud, int iud)
  42 {
  43     /* Get the env table from the object */
  44     lua_getfenv(L, ud);
  45     void *pointer = luaA_object_incref(L, -1, iud < 0 ? iud - 1 : iud);
  46     /* Remove env table */
  47     lua_pop(L, 1);
  48     return pointer;
  49 }
  50
  51 /** Unref an item from the environment table of an object.
  52  * \param L The Lua VM state.
  53  * \param ud The index of the object on the stack.
  54  * \param ref item.
  55  */
  56 static inline void
  57 luaA_object_unref_item(lua_State *L, int ud, void *pointer)
  58 {
  59     /* Get the env table from the object */
  60     lua_getfenv(L, ud);
  61     /* Decrement */
  62     luaA_object_decref(L, -1, pointer);
  63     /* Remove env table */
  64     lua_pop(L, 1);
  65 }
  66
  67 /** Push an object item on the stack.
  68  * \param L The Lua VM state.
  69  * \param ud The object index on the stack.
  70  * \param pointer The item pointer.
  71  * \return The number of element pushed on stack.
  72  */
  73 static inline int
  74 luaA_object_push_item(lua_State *L, int ud, void *pointer)
  75 {
  76     /* Get env table of the object */
  77     lua_getfenv(L, ud);
  78     /* Push key */
  79     lua_pushlightuserdata(L, pointer);
  80     /* Get env.pointer */
  81     lua_rawget(L, -2);
  82     /* Remove env table */
  83     lua_remove(L, -2);
  84     return 1;
  85 }
  86
  87 static inline void
  88 luaA_object_registry_push(lua_State *L)
  89 {
  90     lua_pushliteral(L, LUAA_OBJECT_REGISTRY_KEY);
  91     lua_rawget(L, LUA_REGISTRYINDEX);
  92 }
  93
  94 /** Reference an object and return a pointer to it.
  95  * That only works with userdata, table, thread or function.
  96  * \param L The Lua VM state.
  97  * \param oud The object index on the stack.
  98  * \return The object reference, or NULL if not referencable.
  99  */
 100 static inline void *
 101 luaA_object_ref(lua_State *L, int oud)
 102 {
 103     luaA_object_registry_push(L);
 104     void *p = luaA_object_incref(L, -1, oud < 0 ? oud - 1 : oud);
 105     lua_pop(L, 1);
 106     return p;
 107 }
 108
 109 /** Unreference an object and return a pointer to it.
 110  * That only works with userdata, table, thread or function.
 111  * \param L The Lua VM state.
 112  * \param oud The object index on the stack.
 113  */
 114 static inline void
 115 luaA_object_unref(lua_State *L, void *pointer)
 116 {
 117     luaA_object_registry_push(L);
 118     luaA_object_decref(L, -1, pointer);
 119     lua_pop(L, 1);
 120 }
 121
 122 /** Push a referenced object onto the stack.
 123  * \param L The Lua VM state.
 124  * \param pointer The object to push.
 125  * \return The number of element pushed on stack.
 126  */
 127 static inline int
 128 luaA_object_push(lua_State *L, void *pointer)
 129 {
 130     luaA_object_registry_push(L);
 131     lua_pushlightuserdata(L, pointer);
 132     lua_rawget(L, -2);
 133     lua_remove(L, -2);
 134     return 1;
 135 }
 136
 137 void signal_object_emit(lua_State *, signal_array_t *, const char *, int);
 138
 139 void luaA_object_add_signal(lua_State *, int, const char *, int);
 140 void luaA_object_remove_signal(lua_State *, int, const char *, int);
 141 void luaA_object_emit_signal(lua_State *, int, const char *, int);
 142
 143 int luaA_object_add_signal_simple(lua_State *);
 144 int luaA_object_remove_signal_simple(lua_State *);
 145 int luaA_object_emit_signal_simple(lua_State *);
 146
 147 #define LUA_OBJECT_FUNCS(lua_class, type, prefix)                              \
 148     LUA_CLASS_FUNCS(prefix, lua_class)                                         \
 149     static inline type *                                                       \
 150     prefix##_new(lua_State *L)                                                 \
 151     {                                                                          \
 152         type *p = lua_newuserdata(L, sizeof(type));                            \
 153         p_clear(p, 1);                                                         \
 154         luaA_settype(L, &(lua_class));                                         \
 155         lua_newtable(L);                                                       \
 156         lua_newtable(L);                                                       \
 157         lua_setmetatable(L, -2);                                               \
 158         lua_setfenv(L, -2);                                                    \
 159         lua_pushvalue(L, -1);                                                  \
 160         luaA_class_emit_signal(L, &(lua_class), "new", 1);                     \
 161         return p;                                                              \
 162     }
 163
 164 #define OBJECT_EXPORT_PROPERTY(pfx, type, field) \
 165     fieldtypeof(type, field) \
 166     pfx##_get_##field(type *object) \
 167     { \
 168         return object->field; \
 169     }
 170
 171 #define LUA_OBJECT_EXPORT_PROPERTY(pfx, type, field, pusher) \
 172     static int \
 173     luaA_##pfx##_get_##field(lua_State *L, type *object) \
 174     { \
 175         pusher(L, object->field); \
 176         return 1; \
 177     }
 178
 179 int luaA_object_tostring(lua_State *);
 180 int luaA_object_gc(lua_State *);
 181
 182 #define LUA_OBJECT_META(prefix) \
 183     { "__tostring", luaA_object_tostring }, \
 184     { "add_signal", luaA_object_add_signal_simple }, \
 185     { "remove_signal", luaA_object_remove_signal_simple }, \
 186     { "emit_signal", luaA_object_emit_signal_simple },
 187
 188 #endif
 189
 190 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=80