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 #include "luaa.h"
  27
  28 #define LUAA_OBJECT_REGISTRY_KEY "awesome.object.registry"
  29
  30 int luaA_settype(lua_State *, lua_class_t *);
  31 void luaA_object_setup(lua_State *);
  32 void * luaA_object_incref(lua_State *, int, int);
  33 void luaA_object_decref(lua_State *, int, const void *);
  34
  35 /** Store an item in the environment table of an object.
  36  * \param L The Lua VM state.
  37  * \param ud The index of the object on the stack.
  38  * \param iud The index of the item on the stack.
  39  * \return The item reference.
  40  */
  41 static inline void *
  42 luaA_object_ref_item(lua_State *L, int ud, int iud)
  43 {
  44     /* Get the env table from the object */
  45     luaA_getuservalue(L, ud);
  46     void *pointer = luaA_object_incref(L, -1, iud < 0 ? iud - 1 : iud);
  47     /* Remove env table */
  48     lua_pop(L, 1);
  49     return pointer;
  50 }
  51
  52 /** Unref an item from the environment table of an object.
  53  * \param L The Lua VM state.
  54  * \param ud The index of the object on the stack.
  55  * \param ref item.
  56  */
  57 static inline void
  58 luaA_object_unref_item(lua_State *L, int ud, void *pointer)
  59 {
  60     /* Get the env table from the object */
  61     luaA_getuservalue(L, ud);
  62     /* Decrement */
  63     luaA_object_decref(L, -1, pointer);
  64     /* Remove env table */
  65     lua_pop(L, 1);
  66 }
  67
  68 /** Push an object item on the stack.
  69  * \param L The Lua VM state.
  70  * \param ud The object index on the stack.
  71  * \param pointer The item pointer.
  72  * \return The number of element pushed on stack.
  73  */
  74 static inline int
  75 luaA_object_push_item(lua_State *L, int ud, const void *pointer)
  76 {
  77     /* Get env table of the object */
  78     luaA_getuservalue(L, ud);
  79     /* Push key */
  80     lua_pushlightuserdata(L, (void *) pointer);
  81     /* Get env.pointer */
  82     lua_rawget(L, -2);
  83     /* Remove env table */
  84     lua_remove(L, -2);
  85     return 1;
  86 }
  87
  88 static inline void
  89 luaA_object_registry_push(lua_State *L)
  90 {
  91     lua_pushliteral(L, LUAA_OBJECT_REGISTRY_KEY);
  92     lua_rawget(L, LUA_REGISTRYINDEX);
  93 }
  94
  95 /** Reference an object and return a pointer to it.
  96  * That only works with userdata, table, thread or function.
  97  * \param L The Lua VM state.
  98  * \param oud The object index on the stack.
  99  * \return The object reference, or NULL if not referenceable.
 100  */
 101 static inline void *
 102 luaA_object_ref(lua_State *L, int oud)
 103 {
 104     luaA_object_registry_push(L);
 105     void *p = luaA_object_incref(L, -1, oud < 0 ? oud - 1 : oud);
 106     lua_pop(L, 1);
 107     return p;
 108 }
 109
 110 /** Reference an object and return a pointer to it checking its type.
 111  * That only works with userdata.
 112  * \param L The Lua VM state.
 113  * \param oud The object index on the stack.
 114  * \param class The class of object expected
 115  * \return The object reference, or NULL if not referenceable.
 116  */
 117 static inline void *
 118 luaA_object_ref_class(lua_State *L, int oud, lua_class_t *class)
 119 {
 120     luaA_checkudata(L, oud, class);
 121     return luaA_object_ref(L, oud);
 122 }
 123
 124 /** Unreference an object and return a pointer to it.
 125  * That only works with userdata, table, thread or function.
 126  * \param L The Lua VM state.
 127  * \param oud The object index on the stack.
 128  */
 129 static inline void
 130 luaA_object_unref(lua_State *L, const void *pointer)
 131 {
 132     luaA_object_registry_push(L);
 133     luaA_object_decref(L, -1, pointer);
 134     lua_pop(L, 1);
 135 }
 136
 137 /** Push a referenced object onto the stack.
 138  * \param L The Lua VM state.
 139  * \param pointer The object to push.
 140  * \return The number of element pushed on stack.
 141  */
 142 static inline int
 143 luaA_object_push(lua_State *L, const void *pointer)
 144 {
 145     luaA_object_registry_push(L);
 146     lua_pushlightuserdata(L, (void *) pointer);
 147     lua_rawget(L, -2);
 148     lua_remove(L, -2);
 149     return 1;
 150 }
 151
 152 void signal_object_emit(lua_State *, signal_array_t *, const char *, int);
 153
 154 void luaA_object_connect_signal(lua_State *, int, const char *, lua_CFunction);
 155 void luaA_object_disconnect_signal(lua_State *, int, const char *, lua_CFunction);
 156 void luaA_object_connect_signal_from_stack(lua_State *, int, const char *, int);
 157 void luaA_object_disconnect_signal_from_stack(lua_State *, int, const char *, int);
 158 void luaA_object_emit_signal(lua_State *, int, const char *, int);
 159
 160 int luaA_object_connect_signal_simple(lua_State *);
 161 int luaA_object_disconnect_signal_simple(lua_State *);
 162 int luaA_object_emit_signal_simple(lua_State *);
 163
 164 #define LUA_OBJECT_FUNCS(lua_class, type, prefix)                              \
 165     LUA_CLASS_FUNCS(prefix, lua_class)                                         \
 166     static inline type *                                                       \
 167     prefix##_new(lua_State *L)                                                 \
 168     {                                                                          \
 169         type *p = lua_newuserdata(L, sizeof(type));                            \
 170         p_clear(p, 1);                                                         \
 171         (lua_class).instances++;                                               \
 172         luaA_settype(L, &(lua_class));                                         \
 173         lua_newtable(L);                                                       \
 174         lua_newtable(L);                                                       \
 175         lua_setmetatable(L, -2);                                               \
 176         luaA_setuservalue(L, -2);                                              \
 177         lua_pushvalue(L, -1);                                                  \
 178         p->signals.inherits_from = &(lua_class).signals;                       \
 179         luaA_class_emit_signal(L, &(lua_class), "new", 1);                     \
 180         return p;                                                              \
 181     }
 182
 183 #define OBJECT_EXPORT_PROPERTY(pfx, type, field) \
 184     fieldtypeof(type, field) \
 185     pfx##_get_##field(type *object) \
 186     { \
 187         return object->field; \
 188     }
 189
 190 #define LUA_OBJECT_EXPORT_PROPERTY(pfx, type, field, pusher) \
 191     static int \
 192     luaA_##pfx##_get_##field(lua_State *L, type *object) \
 193     { \
 194         pusher(L, object->field); \
 195         return 1; \
 196     }
 197
 198 int luaA_object_tostring(lua_State *);
 199
 200 #define LUA_OBJECT_META(prefix) \
 201     { "__tostring", luaA_object_tostring }, \
 202     { "connect_signal", luaA_object_connect_signal_simple }, \
 203     { "disconnect_signal", luaA_object_disconnect_signal_simple }, \
 204     { "emit_signal", luaA_object_emit_signal_simple },
 205
 206 #endif
 207
 208 // vim: filetype=c:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80