/*
* Generic object newindex metamethod handler.
* Lua Stack: ud, key, value
*/
int object_newindex_handler(lua_State *L)
{
char sskey[16], *skey;
if ((!lua_isstring(L, 2)) || (!lua_isstring(L, 3))){
gr_object_t *ud = toobject(L, 1, NULL, STRICT);
skey = agget(ud->p.p, ".attrib");
if (!skey || (strlen(skey) == 0)){
/* Let's create an attrib table on the fly if none exists */
sprintf(sskey, "%p", ud->p.p);
skey = agstrdup(sskey);
agset(ud->p.p, ".attrib", skey);
lua_pushstring(L, skey); /* ud, key, value, skey */
lua_newtable(L); /* ud, key, value, skey, stab */
lua_rawset(L, LUA_REGISTRYINDEX); /* ud, key, value, */
}
lua_pushstring(L, skey); /* ud, key, value, skey */
lua_rawget(L, LUA_REGISTRYINDEX); /* ud, key, value, stab */
lua_pushvalue(L, 2); /* ud, key, value, stab, key */
lua_pushvalue(L, 3); /* ud, key, value, stab, key, value */
lua_rawset(L, -3); /* ud, key, value, stab */
lua_pop(L, -1); /* ud, key, value */
return 0;
}
return setval(L);
}
/*
* Set a value to a graphviz object attribute
*/
static int setval(lua_State *L)
{
gr_object_t *ud = toobject(L, 1, NULL, STRICT);
char *key = (char *) luaL_checkstring(L, 2);
char *value = (char *) luaL_checkstring(L, 3);
return agsafeset(ud->p.p, key, value, NULL);
}
/*-------------------------------------------------------------------------*\
* Generic method: type = obj.type(self)
* Returns type of a graph object.
* Returns the type as string: 'graph', 'node' or 'edge'.
* Example:
* type = n:type()
\*-------------------------------------------------------------------------*/
int get_object_type(lua_State *L)
{
gr_object_t *ud = toobject(L, 1, NULL, STRICT);
lua_pushstring(L, AGTYPE(ud->p.p) == AGGRAPH ? "graph" :
AGTYPE(ud->p.p) == AGNODE ? "node" :
AGTYPE(ud->p.p) == AGEDGE ? "edge" : "unkown");
return 1;
}
/*
* Get the value of a graphviz object attribute
*/
int getval(lua_State *L)
{
gr_object_t *ud = toobject(L, 1, NULL, STRICT);
char *key = (char *) luaL_checkstring(L, 2);
char *value = agget(ud->p.p, key);
if (!value || strlen(value) == 0){
lua_pushnil(L);
return 1;
}
lua_pushstring(L, value);
return 1;
}
/*
* Generic object index metamethod handler
* This closure has 2 upvalues:
* 1. table with read members (this is the metatable)
* 2. metatable.__metatable contains the methods
* Lua stack: ud, key
*/
int object_index_handler(lua_State *L)
{
gr_object_t *ud;
char *skey;
/* Read member lookup in first upvalue */
lua_pushvalue(L, 2); /* ud, key, key */
lua_rawget(L, lua_upvalueindex(1)); /* ud, key, getfunc (member) or nil (method) */
if (!lua_isfunction(L, -1)){
/* Member not found - try methods */
lua_pop(L, 1); /* ud, key */
lua_pushvalue(L, 2); /* ud, key, key */
lua_gettable(L, lua_upvalueindex(2)); /* ud, key, method */
if (lua_isnil(L, -1)){
/* Try generic get method */
if (lua_isstring(L, 2)){
lua_settop(L, 2); /* ud, key */
lua_pushcfunction(L, getval); /* ud, key, gr_get */
lua_pushvalue(L, 1); /* ud, key, gr_get, ud */
lua_pushvalue(L, 2); /* ud, key, gr_get, ud, key */
lua_call(L, 2, 1); /* ud, key, value or nil */
}
if (lua_isnil(L, -1)){
/* Try generic storage */
lua_settop(L, 2); /* ud, key */
ud = toobject(L, 1, NULL, STRICT);
skey = agget(ud->p.p, ".attrib");
if (skey && strlen(skey) > 0){
lua_pushstring(L, skey); /* ud, key, skey */
lua_rawget(L, LUA_REGISTRYINDEX); /* ud, key, stab */
lua_pushvalue(L, 2); /* ud, key, stab, key */
lua_rawget(L, -2); /* ud, key, stab, value */
lua_remove(L, -2); /* ud, key, value */
} else
lua_pushnil(L); /* ud, key, nil */
}
}
return 1;
}
/* Call the member's access function */
lua_pushvalue(L, 1); /* ud, key, getfunc, ud */
lua_pushvalue(L, 2); /* ud, key, getfunc, ud, key */
lua_call(L, 2, 1); /* ud, key, value */
return 1;
}
/*-------------------------------------------------------------------------*\
* Metamethod: __tostring [boolean]
* Return a string presentation of a graph object.
* Example:
* g == h or g != h with metamethods
\*-------------------------------------------------------------------------*/
static int gr_tostring(lua_State *L)
{
gr_object_t *ud = toobject(L, 1, NULL, NONSTRICT);
lua_pushfstring(L, "node: %p (%s)", ud, ud->p.status == ALIVE ? "alive" : "dead");
return 1;
}
