1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
14 * You should have received a copy of the GNU Lesser General
15 * Public License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
17 * Boston, MA 02111-1307, USA.
19 * gvaluecollector.h: GValue varargs stubs
22 * SECTION:value_collection
23 * @Short_description: Converting varargs to generic values
24 * @See_also:#GValueTable
25 * @Title: Varargs Value Collection
27 * The macros in this section provide the varargs parsing support needed
28 * in variadic GObject functions such as g_object_new() or g_object_set().
29 * They currently support the collection of integral types, floating point
32 #ifndef __G_VALUE_COLLECTOR_H__
33 #define __G_VALUE_COLLECTOR_H__
35 #include <glib-object.h>
39 /* we may want to add aggregate types here some day, if requested
40 * by users. the basic C types are covered already, everything
41 * smaller than an int is promoted to an integer and floats are
42 * always promoted to doubles for varargs call constructions.
46 G_VALUE_COLLECT_INT = 'i',
47 G_VALUE_COLLECT_LONG = 'l',
48 G_VALUE_COLLECT_INT64 = 'q',
49 G_VALUE_COLLECT_DOUBLE = 'd',
50 G_VALUE_COLLECT_POINTER = 'p'
54 /* vararg union holding actuall values collected
59 * A union holding one collected value.
72 * @value: a #GValue return location. @value is supposed to be initialized
73 * according to the value type to be collected
74 * @var_args: the va_list variable; it may be evaluated multiple times
75 * @flags: flags which are passed on to the collect_value() function of
76 * the #GTypeValueTable of @value.
77 * @__error: a #gchar** variable that will be modified to hold a g_new()
78 * allocated error messages if something fails
80 * Collects a variable argument value from a va_list. We have to
81 * implement the varargs collection as a macro, because on some systems
82 * va_list variables cannot be passed by reference.
84 #define G_VALUE_COLLECT(value, var_args, flags, __error) \
86 GValue *_value = (value); \
87 guint _flags = (flags); \
88 GType _value_type = G_VALUE_TYPE (_value); \
89 GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \
90 gchar *_collect_format = _vtable->collect_format; \
91 GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
92 guint _n_values = 0; \
94 if (_vtable->value_free) \
95 _vtable->value_free (_value); \
96 _value->g_type = _value_type; /* value_meminit() from gvalue.c */ \
97 memset (_value->data, 0, sizeof (_value->data)); \
98 while (*_collect_format) \
100 GTypeCValue *_cvalue = _cvalues + _n_values++; \
102 switch (*_collect_format++) \
104 case G_VALUE_COLLECT_INT: \
105 _cvalue->v_int = va_arg ((var_args), gint); \
107 case G_VALUE_COLLECT_LONG: \
108 _cvalue->v_long = va_arg ((var_args), glong); \
110 case G_VALUE_COLLECT_INT64: \
111 _cvalue->v_int64 = va_arg ((var_args), gint64); \
113 case G_VALUE_COLLECT_DOUBLE: \
114 _cvalue->v_double = va_arg ((var_args), gdouble); \
116 case G_VALUE_COLLECT_POINTER: \
117 _cvalue->v_pointer = va_arg ((var_args), gpointer); \
120 g_assert_not_reached (); \
123 *(__error) = _vtable->collect_value (_value, \
132 * @value: a #GValue return location. @value is supposed to be initialized
133 * according to the value type to be collected
134 * @var_args: the va_list variable; it may be evaluated multiple times
135 * @flags: flags which are passed on to the lcopy_value() function of
136 * the #GTypeValueTable of @value.
137 * @__error: a #gchar** variable that will be modified to hold a g_new()
138 * allocated error messages if something fails
140 * Collects a value's variable argument locations from a va_list. Usage is
141 * analogous to G_VALUE_COLLECT().
143 #define G_VALUE_LCOPY(value, var_args, flags, __error) \
145 const GValue *_value = (value); \
146 guint _flags = (flags); \
147 GType _value_type = G_VALUE_TYPE (_value); \
148 GTypeValueTable *_vtable = g_type_value_table_peek (_value_type); \
149 gchar *_lcopy_format = _vtable->lcopy_format; \
150 GTypeCValue _cvalues[G_VALUE_COLLECT_FORMAT_MAX_LENGTH] = { { 0, }, }; \
151 guint _n_values = 0; \
153 while (*_lcopy_format) \
155 GTypeCValue *_cvalue = _cvalues + _n_values++; \
157 switch (*_lcopy_format++) \
159 case G_VALUE_COLLECT_INT: \
160 _cvalue->v_int = va_arg ((var_args), gint); \
162 case G_VALUE_COLLECT_LONG: \
163 _cvalue->v_long = va_arg ((var_args), glong); \
165 case G_VALUE_COLLECT_INT64: \
166 _cvalue->v_int64 = va_arg ((var_args), gint64); \
168 case G_VALUE_COLLECT_DOUBLE: \
169 _cvalue->v_double = va_arg ((var_args), gdouble); \
171 case G_VALUE_COLLECT_POINTER: \
172 _cvalue->v_pointer = va_arg ((var_args), gpointer); \
175 g_assert_not_reached (); \
178 *(__error) = _vtable->lcopy_value (_value, \
186 * G_VALUE_COLLECT_FORMAT_MAX_LENGTH:
188 * The maximal number of #GTypeCValue<!-- -->s which can be collected for a
191 #define G_VALUE_COLLECT_FORMAT_MAX_LENGTH (8)
195 #endif /* __G_VALUE_COLLECTOR_H__ */