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, see <http://www.gnu.org/licenses/>.
27 #include "gtype-private.h"
29 #include "gvaluecollector.h"
33 * SECTION:enumerations_flags
34 * @short_description: Enumeration and flags types
35 * @title: Enumeration and Flag Types
36 * @see_also:#GParamSpecEnum, #GParamSpecFlags, g_param_spec_enum(),
37 * g_param_spec_flags()
39 * The GLib type system provides fundamental types for enumeration and
40 * flags types. (Flags types are like enumerations, but allow their
41 * values to be combined by bitwise or). A registered enumeration or
42 * flags type associates a name and a nickname with each allowed
43 * value, and the methods g_enum_get_value_by_name(),
44 * g_enum_get_value_by_nick(), g_flags_get_value_by_name() and
45 * g_flags_get_value_by_nick() can look up values by their name or
46 * nickname. When an enumeration or flags type is registered with the
47 * GLib type system, it can be used as value type for object
48 * properties, using g_param_spec_enum() or g_param_spec_flags().
50 * GObject ships with a utility called [glib-mkenums][glib-mkenums],
51 * that can construct suitable type registration functions from C enumeration
56 /* --- prototypes --- */
57 static void g_enum_class_init (GEnumClass *class,
59 static void g_flags_class_init (GFlagsClass *class,
61 static void value_flags_enum_init (GValue *value);
62 static void value_flags_enum_copy_value (const GValue *src_value,
64 static gchar* value_flags_enum_collect_value (GValue *value,
65 guint n_collect_values,
66 GTypeCValue *collect_values,
68 static gchar* value_flags_enum_lcopy_value (const GValue *value,
69 guint n_collect_values,
70 GTypeCValue *collect_values,
73 /* --- functions --- */
75 _g_enum_types_init (void)
77 static gboolean initialized = FALSE;
78 static const GTypeValueTable flags_enum_value_table = {
79 value_flags_enum_init, /* value_init */
80 NULL, /* value_free */
81 value_flags_enum_copy_value, /* value_copy */
82 NULL, /* value_peek_pointer */
83 "i", /* collect_format */
84 value_flags_enum_collect_value, /* collect_value */
85 "p", /* lcopy_format */
86 value_flags_enum_lcopy_value, /* lcopy_value */
91 NULL, /* base_destroy */
92 NULL, /* class_init */
93 NULL, /* class_destroy */
94 NULL, /* class_data */
95 0, /* instance_size */
97 NULL, /* instance_init */
98 &flags_enum_value_table, /* value_table */
100 static const GTypeFundamentalInfo finfo = {
101 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_DERIVABLE,
105 g_return_if_fail (initialized == FALSE);
110 info.class_size = sizeof (GEnumClass);
111 type = g_type_register_fundamental (G_TYPE_ENUM, g_intern_static_string ("GEnum"), &info, &finfo,
112 G_TYPE_FLAG_ABSTRACT | G_TYPE_FLAG_VALUE_ABSTRACT);
113 g_assert (type == G_TYPE_ENUM);
117 info.class_size = sizeof (GFlagsClass);
118 type = g_type_register_fundamental (G_TYPE_FLAGS, g_intern_static_string ("GFlags"), &info, &finfo,
119 G_TYPE_FLAG_ABSTRACT | G_TYPE_FLAG_VALUE_ABSTRACT);
120 g_assert (type == G_TYPE_FLAGS);
124 value_flags_enum_init (GValue *value)
126 value->data[0].v_long = 0;
130 value_flags_enum_copy_value (const GValue *src_value,
133 dest_value->data[0].v_long = src_value->data[0].v_long;
137 value_flags_enum_collect_value (GValue *value,
138 guint n_collect_values,
139 GTypeCValue *collect_values,
142 value->data[0].v_long = collect_values[0].v_int;
148 value_flags_enum_lcopy_value (const GValue *value,
149 guint n_collect_values,
150 GTypeCValue *collect_values,
153 gint *int_p = collect_values[0].v_pointer;
156 return g_strdup_printf ("value location for '%s' passed as NULL", G_VALUE_TYPE_NAME (value));
158 *int_p = value->data[0].v_long;
164 * g_enum_register_static:
165 * @name: A nul-terminated string used as the name of the new type.
166 * @const_static_values: An array of #GEnumValue structs for the possible
167 * enumeration values. The array is terminated by a struct with all
168 * members being 0. GObject keeps a reference to the data, so it cannot
169 * be stack-allocated.
171 * Registers a new static enumeration type with the name @name.
173 * It is normally more convenient to let [glib-mkenums][glib-mkenums],
174 * generate a my_enum_get_type() function from a usual C enumeration
175 * definition than to write one yourself using g_enum_register_static().
177 * Returns: The new type identifier.
180 g_enum_register_static (const gchar *name,
181 const GEnumValue *const_static_values)
183 GTypeInfo enum_type_info = {
184 sizeof (GEnumClass), /* class_size */
185 NULL, /* base_init */
186 NULL, /* base_finalize */
187 (GClassInitFunc) g_enum_class_init,
188 NULL, /* class_finalize */
189 NULL, /* class_data */
190 0, /* instance_size */
192 NULL, /* instance_init */
193 NULL, /* value_table */
197 g_return_val_if_fail (name != NULL, 0);
198 g_return_val_if_fail (const_static_values != NULL, 0);
200 enum_type_info.class_data = const_static_values;
202 type = g_type_register_static (G_TYPE_ENUM, name, &enum_type_info, 0);
208 * g_flags_register_static:
209 * @name: A nul-terminated string used as the name of the new type.
210 * @const_static_values: An array of #GFlagsValue structs for the possible
211 * flags values. The array is terminated by a struct with all members being 0.
212 * GObject keeps a reference to the data, so it cannot be stack-allocated.
214 * Registers a new static flags type with the name @name.
216 * It is normally more convenient to let [glib-mkenums][glib-mkenums]
217 * generate a my_flags_get_type() function from a usual C enumeration
218 * definition than to write one yourself using g_flags_register_static().
220 * Returns: The new type identifier.
223 g_flags_register_static (const gchar *name,
224 const GFlagsValue *const_static_values)
226 GTypeInfo flags_type_info = {
227 sizeof (GFlagsClass), /* class_size */
228 NULL, /* base_init */
229 NULL, /* base_finalize */
230 (GClassInitFunc) g_flags_class_init,
231 NULL, /* class_finalize */
232 NULL, /* class_data */
233 0, /* instance_size */
235 NULL, /* instance_init */
236 NULL, /* value_table */
240 g_return_val_if_fail (name != NULL, 0);
241 g_return_val_if_fail (const_static_values != NULL, 0);
243 flags_type_info.class_data = const_static_values;
245 type = g_type_register_static (G_TYPE_FLAGS, name, &flags_type_info, 0);
251 * g_enum_complete_type_info:
252 * @g_enum_type: the type identifier of the type being completed
253 * @info: (out callee-allocates): the #GTypeInfo struct to be filled in
254 * @const_values: An array of #GEnumValue structs for the possible
255 * enumeration values. The array is terminated by a struct with all
258 * This function is meant to be called from the `complete_type_info`
259 * function of a #GTypePlugin implementation, as in the following
262 * |[<!-- language="C" -->
264 * my_enum_complete_type_info (GTypePlugin *plugin,
267 * GTypeValueTable *value_table)
269 * static const GEnumValue values[] = {
270 * { MY_ENUM_FOO, "MY_ENUM_FOO", "foo" },
271 * { MY_ENUM_BAR, "MY_ENUM_BAR", "bar" },
275 * g_enum_complete_type_info (type, info, values);
280 g_enum_complete_type_info (GType g_enum_type,
282 const GEnumValue *const_values)
284 g_return_if_fail (G_TYPE_IS_ENUM (g_enum_type));
285 g_return_if_fail (info != NULL);
286 g_return_if_fail (const_values != NULL);
288 info->class_size = sizeof (GEnumClass);
289 info->base_init = NULL;
290 info->base_finalize = NULL;
291 info->class_init = (GClassInitFunc) g_enum_class_init;
292 info->class_finalize = NULL;
293 info->class_data = const_values;
297 * g_flags_complete_type_info:
298 * @g_flags_type: the type identifier of the type being completed
299 * @info: (out callee-allocates): the #GTypeInfo struct to be filled in
300 * @const_values: An array of #GFlagsValue structs for the possible
301 * enumeration values. The array is terminated by a struct with all
304 * This function is meant to be called from the complete_type_info()
305 * function of a #GTypePlugin implementation, see the example for
306 * g_enum_complete_type_info() above.
309 g_flags_complete_type_info (GType g_flags_type,
311 const GFlagsValue *const_values)
313 g_return_if_fail (G_TYPE_IS_FLAGS (g_flags_type));
314 g_return_if_fail (info != NULL);
315 g_return_if_fail (const_values != NULL);
317 info->class_size = sizeof (GFlagsClass);
318 info->base_init = NULL;
319 info->base_finalize = NULL;
320 info->class_init = (GClassInitFunc) g_flags_class_init;
321 info->class_finalize = NULL;
322 info->class_data = const_values;
326 g_enum_class_init (GEnumClass *class,
329 g_return_if_fail (G_IS_ENUM_CLASS (class));
334 class->values = class_data;
340 class->minimum = class->values->value;
341 class->maximum = class->values->value;
342 for (values = class->values; values->value_name; values++)
344 class->minimum = MIN (class->minimum, values->value);
345 class->maximum = MAX (class->maximum, values->value);
352 g_flags_class_init (GFlagsClass *class,
355 g_return_if_fail (G_IS_FLAGS_CLASS (class));
359 class->values = class_data;
365 for (values = class->values; values->value_name; values++)
367 class->mask |= values->value;
374 * g_enum_get_value_by_name:
375 * @enum_class: a #GEnumClass
376 * @name: the name to look up
378 * Looks up a #GEnumValue by name.
380 * Returns: (transfer none): the #GEnumValue with name @name,
381 * or %NULL if the enumeration doesn't have a member
385 g_enum_get_value_by_name (GEnumClass *enum_class,
388 g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
389 g_return_val_if_fail (name != NULL, NULL);
391 if (enum_class->n_values)
393 GEnumValue *enum_value;
395 for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
396 if (strcmp (name, enum_value->value_name) == 0)
404 * g_flags_get_value_by_name:
405 * @flags_class: a #GFlagsClass
406 * @name: the name to look up
408 * Looks up a #GFlagsValue by name.
410 * Returns: (transfer none): the #GFlagsValue with name @name,
411 * or %NULL if there is no flag with that name
414 g_flags_get_value_by_name (GFlagsClass *flags_class,
417 g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
418 g_return_val_if_fail (name != NULL, NULL);
420 if (flags_class->n_values)
422 GFlagsValue *flags_value;
424 for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
425 if (strcmp (name, flags_value->value_name) == 0)
433 * g_enum_get_value_by_nick:
434 * @enum_class: a #GEnumClass
435 * @nick: the nickname to look up
437 * Looks up a #GEnumValue by nickname.
439 * Returns: (transfer none): the #GEnumValue with nickname @nick,
440 * or %NULL if the enumeration doesn't have a member
444 g_enum_get_value_by_nick (GEnumClass *enum_class,
447 g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
448 g_return_val_if_fail (nick != NULL, NULL);
450 if (enum_class->n_values)
452 GEnumValue *enum_value;
454 for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
455 if (enum_value->value_nick && strcmp (nick, enum_value->value_nick) == 0)
463 * g_flags_get_value_by_nick:
464 * @flags_class: a #GFlagsClass
465 * @nick: the nickname to look up
467 * Looks up a #GFlagsValue by nickname.
469 * Returns: (transfer none): the #GFlagsValue with nickname @nick,
470 * or %NULL if there is no flag with that nickname
473 g_flags_get_value_by_nick (GFlagsClass *flags_class,
476 g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
477 g_return_val_if_fail (nick != NULL, NULL);
479 if (flags_class->n_values)
481 GFlagsValue *flags_value;
483 for (flags_value = flags_class->values; flags_value->value_nick; flags_value++)
484 if (flags_value->value_nick && strcmp (nick, flags_value->value_nick) == 0)
493 * @enum_class: a #GEnumClass
494 * @value: the value to look up
496 * Returns the #GEnumValue for a value.
498 * Returns: (transfer none): the #GEnumValue for @value, or %NULL
499 * if @value is not a member of the enumeration
502 g_enum_get_value (GEnumClass *enum_class,
505 g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
507 if (enum_class->n_values)
509 GEnumValue *enum_value;
511 for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
512 if (enum_value->value == value)
520 * g_flags_get_first_value:
521 * @flags_class: a #GFlagsClass
524 * Returns the first #GFlagsValue which is set in @value.
526 * Returns: (transfer none): the first #GFlagsValue which is set in
527 * @value, or %NULL if none is set
530 g_flags_get_first_value (GFlagsClass *flags_class,
533 g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
535 if (flags_class->n_values)
537 GFlagsValue *flags_value;
541 for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
542 if (flags_value->value == 0)
547 for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
548 if (flags_value->value != 0 && (flags_value->value & value) == flags_value->value)
558 * @value: a valid #GValue whose type is derived from %G_TYPE_ENUM
559 * @v_enum: enum value to be set
561 * Set the contents of a %G_TYPE_ENUM #GValue to @v_enum.
564 g_value_set_enum (GValue *value,
567 g_return_if_fail (G_VALUE_HOLDS_ENUM (value));
569 value->data[0].v_long = v_enum;
574 * @value: a valid #GValue whose type is derived from %G_TYPE_ENUM
576 * Get the contents of a %G_TYPE_ENUM #GValue.
578 * Returns: enum contents of @value
581 g_value_get_enum (const GValue *value)
583 g_return_val_if_fail (G_VALUE_HOLDS_ENUM (value), 0);
585 return value->data[0].v_long;
590 * @value: a valid #GValue whose type is derived from %G_TYPE_FLAGS
591 * @v_flags: flags value to be set
593 * Set the contents of a %G_TYPE_FLAGS #GValue to @v_flags.
596 g_value_set_flags (GValue *value,
599 g_return_if_fail (G_VALUE_HOLDS_FLAGS (value));
601 value->data[0].v_ulong = v_flags;
606 * @value: a valid #GValue whose type is derived from %G_TYPE_FLAGS
608 * Get the contents of a %G_TYPE_FLAGS #GValue.
610 * Returns: flags contents of @value
613 g_value_get_flags (const GValue *value)
615 g_return_val_if_fail (G_VALUE_HOLDS_FLAGS (value), 0);
617 return value->data[0].v_ulong;