JezK

Edit File: gvaluecollector.h

/* GObject - GLib Type, Object, Parameter and Signal Library * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General * Public License along with this library; if not, see <http://www.gnu.org/licenses/>. * * gvaluecollector.h: GValue varargs stubs */ /** * SECTION:value_collection * @Short_description: Converting varargs to generic values * @Title: Varargs Value Collection * * The macros in this section provide the varargs parsing support needed * in variadic GObject functions such as g_object_new() or g_object_set(). * They currently support the collection of integral types, floating point * types and pointers. */ #ifndef __G_VALUE_COLLECTOR_H__ #define __G_VALUE_COLLECTOR_H__ #include <glib-object.h> G_BEGIN_DECLS /* we may want to add aggregate types here some day, if requested * by users. the basic C types are covered already, everything * smaller than an int is promoted to an integer and floats are * always promoted to doubles for varargs call constructions. */ enum /*< skip >*/ { G_VALUE_COLLECT_INT = 'i', G_VALUE_COLLECT_LONG = 'l', G_VALUE_COLLECT_INT64 = 'q', G_VALUE_COLLECT_DOUBLE = 'd', G_VALUE_COLLECT_POINTER = 'p' }; /* vararg union holding actual values collected */ /** * GTypeCValue: * @v_int: the field for holding integer values * @v_long: the field for holding long integer values * @v_int64: the field for holding 64 bit integer values * @v_double: the field for holding floating point values * @v_pointer: the field for holding pointers * * A union holding one collected value. */ union _GTypeCValue { gint v_int; glong v_long; gint64 v_int64; gdouble v_double; gpointer v_pointer; }; /** * G_VALUE_COLLECT_INIT: * @value: a #GValue return location. @value must contain only 0 bytes. * @_value_type: the #GType to use for @value. * @var_args: the va_list variable; it may be evaluated multiple times * @flags: flags which are passed on to the collect_value() function of * the #GTypeValueTable of @value. * @__error: a #gchar** variable that will be modified to hold a g_new() * allocated error messages if something fails * * Collects a variable argument value from a va_list. We have to * implement the varargs collection as a macro, because on some systems * va_list variables cannot be passed by reference. * * Since: 2.24 */ #define G_VALUE_COLLECT_INIT(value, _value_type, var_args, flags, __error) \ G_STMT_START { \ GValue *g_vci_val = (value); \ guint g_vci_flags = (flags); \ GTypeValueTable *g_vci_vtab = g_type_value_table_peek (_value_type); \ const gchar *g_vci_collect_format = g_vci_vtab->collect_format; \ GTypeCValue g_vci_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ guint g_vci_n_values = 0; \ \ g_vci_val->g_type = _value_type; /* value_meminit() from gvalue.c */ \ while (*g_vci_collect_format) \ { \ GTypeCValue *g_vci_cvalue = g_vci_cvalues + g_vci_n_values++; \ \ switch (*g_vci_collect_format++) \ { \ case G_VALUE_COLLECT_INT: \ g_vci_cvalue->v_int = va_arg ((var_args), gint); \ break; \ case G_VALUE_COLLECT_LONG: \ g_vci_cvalue->v_long = va_arg ((var_args), glong); \ break; \ case G_VALUE_COLLECT_INT64: \ g_vci_cvalue->v_int64 = va_arg ((var_args), gint64); \ break; \ case G_VALUE_COLLECT_DOUBLE: \ g_vci_cvalue->v_double = va_arg ((var_args), gdouble); \ break; \ case G_VALUE_COLLECT_POINTER: \ g_vci_cvalue->v_pointer = va_arg ((var_args), gpointer); \ break; \ default: \ g_assert_not_reached (); \ } \ } \ *(__error) = g_vci_vtab->collect_value (g_vci_val, \ g_vci_n_values, \ g_vci_cvalues, \ g_vci_flags); \ } G_STMT_END /** * G_VALUE_COLLECT: * @value: a #GValue return location. @value is supposed to be initialized * according to the value type to be collected * @var_args: the va_list variable; it may be evaluated multiple times * @flags: flags which are passed on to the collect_value() function of * the #GTypeValueTable of @value. * @__error: a #gchar** variable that will be modified to hold a g_new() * allocated error messages if something fails * * Collects a variable argument value from a va_list. We have to * implement the varargs collection as a macro, because on some systems * va_list variables cannot be passed by reference. * * Note: If you are creating the @value argument just before calling this macro, * you should use the #G_VALUE_COLLECT_INIT variant and pass the uninitialized * #GValue. That variant is faster than #G_VALUE_COLLECT. */ #define G_VALUE_COLLECT(value, var_args, flags, __error) G_STMT_START { \ GValue *g_vc_value = (value); \ GType g_vc_value_type = G_VALUE_TYPE (g_vc_value); \ GTypeValueTable *g_vc_vtable = g_type_value_table_peek (g_vc_value_type); \ \ if (g_vc_vtable->value_free) \ g_vc_vtable->value_free (g_vc_value); \ memset (g_vc_value->data, 0, sizeof (g_vc_value->data)); \ \ G_VALUE_COLLECT_INIT(value, g_vc_value_type, var_args, flags, __error); \ } G_STMT_END /** * G_VALUE_COLLECT_SKIP: * @_value_type: the #GType of the value to skip * @var_args: the va_list variable; it may be evaluated multiple times * * Skip an argument of type @_value_type from @var_args. */ #define G_VALUE_COLLECT_SKIP(_value_type, var_args) \ G_STMT_START { \ GTypeValueTable *g_vcs_vtable = g_type_value_table_peek (_value_type); \ const gchar *g_vcs_collect_format = g_vcs_vtable->collect_format; \ \ while (*g_vcs_collect_format) \ { \ switch (*g_vcs_collect_format++) \ { \ case G_VALUE_COLLECT_INT: \ va_arg ((var_args), gint); \ break; \ case G_VALUE_COLLECT_LONG: \ va_arg ((var_args), glong); \ break; \ case G_VALUE_COLLECT_INT64: \ va_arg ((var_args), gint64); \ break; \ case G_VALUE_COLLECT_DOUBLE: \ va_arg ((var_args), gdouble); \ break; \ case G_VALUE_COLLECT_POINTER: \ va_arg ((var_args), gpointer); \ break; \ default: \ g_assert_not_reached (); \ } \ } \ } G_STMT_END /** * G_VALUE_LCOPY: * @value: a #GValue to store into the @var_args; this must be initialized * and set * @var_args: the va_list variable; it may be evaluated multiple times * @flags: flags which are passed on to the lcopy_value() function of * the #GTypeValueTable of @value. * @__error: a #gchar** variable that will be modified to hold a g_new() * allocated error message if something fails * * Stores a value’s value into one or more argument locations from a va_list. * This is the inverse of G_VALUE_COLLECT(). */ #define G_VALUE_LCOPY(value, var_args, flags, __error) \ G_STMT_START { \ const GValue *g_vl_value = (value); \ guint g_vl_flags = (flags); \ GType g_vl_value_type = G_VALUE_TYPE (g_vl_value); \ GTypeValueTable *g_vl_vtable = g_type_value_table_peek (g_vl_value_type); \ const gchar *g_vl_lcopy_format = g_vl_vtable->lcopy_format; \ GTypeCValue g_vl_cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \ guint g_vl_n_values = 0; \ \ while (*g_vl_lcopy_format) \ { \ GTypeCValue *g_vl_cvalue = g_vl_cvalues + g_vl_n_values++; \ \ switch (*g_vl_lcopy_format++) \ { \ case G_VALUE_COLLECT_INT: \ g_vl_cvalue->v_int = va_arg ((var_args), gint); \ break; \ case G_VALUE_COLLECT_LONG: \ g_vl_cvalue->v_long = va_arg ((var_args), glong); \ break; \ case G_VALUE_COLLECT_INT64: \ g_vl_cvalue->v_int64 = va_arg ((var_args), gint64); \ break; \ case G_VALUE_COLLECT_DOUBLE: \ g_vl_cvalue->v_double = va_arg ((var_args), gdouble); \ break; \ case G_VALUE_COLLECT_POINTER: \ g_vl_cvalue->v_pointer = va_arg ((var_args), gpointer); \ break; \ default: \ g_assert_not_reached (); \ } \ } \ *(__error) = g_vl_vtable->lcopy_value (g_vl_value, \ g_vl_n_values, \ g_vl_cvalues, \ g_vl_flags); \ } G_STMT_END /** * G_VALUE_COLLECT_FORMAT_MAX_LENGTH: * * The maximal number of #GTypeCValues which can be collected for a * single #GValue. */ #define G_VALUE_COLLECT_FORMAT_MAX_LENGTH (8) G_END_DECLS #endif /* __G_VALUE_COLLECTOR_H__ */