/* Emit a signal to an object.
* `oud` is the object index on the stack.
* `name` is the name of the signal.
* `nargs` is the number of arguments to pass to the called functions. */
gint
luaH_object_emit_signal(lua_State *L, gint oud,
const gchar *name, gint nargs, gint nret) {
gint ret, top, bot = lua_gettop(L) - nargs + 1;
gint oud_abs = luaH_absindex(L, oud);
lua_object_t *obj = lua_touserdata(L, oud);
if(!obj)
luaL_error(L, "trying to emit signal on non-object");
debug("emitting \"%s\" on %p with %d args and %d nret", name, obj, nargs, nret);
signal_array_t *sigfuncs = signal_lookup(obj->signals, name, FALSE);
if(sigfuncs) {
guint nbfunc = sigfuncs->len;
luaL_checkstack(L, lua_gettop(L) + nbfunc + nargs + 2, "too much signal");
/* Push all functions and then execute, because this list can change
* while executing funcs. */
for(guint i = 0; i < nbfunc; i++)
luaH_object_push_item(L, oud_abs, sigfuncs->pdata[i]);
for(guint i = 0; i < nbfunc; i++) {
/* push object */
lua_pushvalue(L, oud_abs);
/* push all args */
for(gint j = 0; j < nargs; j++)
lua_pushvalue(L, - nargs - nbfunc - 1 + i);
/* push first function */
lua_pushvalue(L, - nargs - nbfunc - 1 + i);
/* remove this first function */
lua_remove(L, - nargs - nbfunc - 2 + i);
top = lua_gettop(L) - 2 - nargs;
luaH_dofunction(L, nargs + 1, LUA_MULTRET);
ret = lua_gettop(L) - top;
/* Note that only if nret && ret will the signal execution stop */
if (ret) {
/* Adjust the number of results to match nret (including 0) */
if (nret != LUA_MULTRET && ret != nret) {
/* Pad with nils */
for (; ret < nret; ret++)
lua_pushnil(L);
/* Or truncate stack */
if (ret > nret) {
lua_pop(L, ret - nret);
ret = nret;
}
}
/* Remove all signal functions and args from the stack */
for (gint i = bot; i < top; i++)
lua_remove(L, bot);
/* Return the number of returned arguments */
return ret;
}
}
}
lua_pop(L, nargs);
return 0;
}
/* Emit a signal to an object.
* `oud` is the object index on the stack.
* `name` is the name of the signal.
* `nargs` is the number of arguments to pass to the called functions.
* `nret` is the number of return values this function pushes onto the stack.
* A positive number means that any missing values will be padded with nil
* and any superfluous values will be removed.
* LUA_MULTRET means that any number of values is returned without any
* adjustment.
* 0 means that all return values are removed and that ALL handler functions are
* executed.
* Returns the number of return values pushed onto the stack. */
gint
luaH_object_emit_signal(lua_State *L, gint oud,
const gchar *name, gint nargs, gint nret) {
gint ret, top, bot = lua_gettop(L) - nargs + 1;
gint oud_abs = luaH_absindex(L, oud);
lua_object_t *obj = lua_touserdata(L, oud);
gchar *origin = luaH_callerinfo(L);
debug("emit " ANSI_COLOR_BLUE "\"%s\"" ANSI_COLOR_RESET
" on %p from "
ANSI_COLOR_GREEN "%s" ANSI_COLOR_RESET " (%d args, %d nret)",
name, obj, origin ? origin : "<GTK>", nargs, nret);
g_free(origin);
if(!obj)
return luaL_error(L, "trying to emit " ANSI_COLOR_BLUE "\"%s\"" ANSI_COLOR_RESET " on non-object", name);
signal_array_t *sigfuncs = signal_lookup(obj->signals, name);
if (sigfuncs) {
guint nbfunc = sigfuncs->len;
luaL_checkstack(L, lua_gettop(L) + nbfunc + nargs + 2,
"too many signal handlers; need a new implementation!");
/* Push all functions and then execute, because this list can change
* while executing funcs. */
for (guint i = 0; i < nbfunc; i++)
luaH_object_push_item(L, oud_abs, sigfuncs->pdata[i]);
for (guint i = 0; i < nbfunc; i++) {
/* push object */
lua_pushvalue(L, oud_abs);
/* push all args */
for (gint j = 0; j < nargs; j++)
lua_pushvalue(L, - nargs - nbfunc - 1 + i);
/* push first function */
lua_pushvalue(L, - nargs - nbfunc - 1 + i);
/* remove this first function */
lua_remove(L, - nargs - nbfunc - 2 + i);
top = lua_gettop(L) - 2 - nargs;
luaH_dofunction(L, nargs + 1, LUA_MULTRET);
ret = lua_gettop(L) - top;
/* Signal execution stops when:
* - there's an expected number of return values (>0 or LUA_MULTRET)
* - at least one return value (ret)
* - the first return value is non-nil
*/
if (nret && ret && !lua_isnil(L, -ret)) {
/* Adjust the number of results to match nret (including 0) */
if (nret != LUA_MULTRET && ret != nret) {
/* Pad with nils */
for (; ret < nret; ret++)
lua_pushnil(L);
/* Or truncate stack */
if (ret > nret) {
lua_pop(L, ret - nret);
ret = nret;
}
}
/* Remove all signal functions and args from the stack */
for (gint i = bot; i <= top; i++)
lua_remove(L, bot);
/* Return the number of returned arguments */
return ret;
} else if (nret == 0) {
/* ignore all return values */
lua_pop(L, ret);
}
}
}
lua_pop(L, nargs);
return 0;
}