1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 1997, 1998, 1999, 2000 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.
23 #include "gvaluecollector.h"
26 /* --- typedefs & structures --- */
36 /* --- variables --- */
37 static GHashTable *param_exchange_ht = NULL;
40 /* --- functions --- */
42 g_value_init (GValue *value,
45 GTypeValueTable *value_table = g_type_value_table_peek (g_type);
47 g_return_if_fail (value != NULL);
48 g_return_if_fail (G_VALUE_TYPE (value) == 0);
52 memset (value, 0, sizeof (*value));
53 value->g_type = g_type;
54 value_table->value_init (value);
57 g_warning (G_STRLOC ": cannot initialize value of type `%s' which has no GTypeValueTable",
58 g_type_name (g_type));
62 g_value_copy (const GValue *src_value,
65 GTypeValueTable *value_table;
67 g_return_if_fail (G_IS_VALUE (src_value));
68 g_return_if_fail (G_IS_VALUE (dest_value));
69 g_return_if_fail (g_type_is_a (G_VALUE_TYPE (src_value), G_VALUE_TYPE (dest_value)));
71 value_table = g_type_value_table_peek (G_VALUE_TYPE (dest_value));
73 g_return_if_fail (g_type_value_table_peek (G_VALUE_TYPE (dest_value)) != NULL);
75 if (src_value != dest_value)
77 /* make sure dest_value's value is free()d and zero initialized */
78 g_value_reset (dest_value);
80 value_table->value_copy (src_value, dest_value);
85 g_value_fits_pointer (const GValue *value)
87 GTypeValueTable *value_table;
89 g_return_val_if_fail (G_IS_VALUE (value), FALSE);
91 value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
93 g_return_val_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL, FALSE);
95 return value_table->value_peek_pointer != NULL;
99 g_value_get_as_pointer (const GValue *value)
101 GTypeValueTable *value_table;
103 g_return_val_if_fail (G_IS_VALUE (value), NULL);
105 value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
107 g_return_val_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL, NULL);
108 if (!value_table->value_peek_pointer)
109 g_return_val_if_fail (g_value_fits_pointer (value) == TRUE, NULL);
111 return value_table->value_peek_pointer (value);
115 g_value_set_instance (GValue *value,
118 g_return_if_fail (G_IS_VALUE (value));
120 g_value_reset (value);
123 GType g_type = G_VALUE_TYPE (value);
124 GTypeValueTable *value_table = g_type_value_table_peek (g_type);
125 GTypeCValue cvalue = { 0, };
127 guint collect_type = value_table->collect_type;
130 g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance));
131 g_return_if_fail (g_type_is_a (G_TYPE_FROM_INSTANCE (instance), G_VALUE_TYPE (value)));
132 g_return_if_fail (value_table->collect_type == G_VALUE_COLLECT_POINTER);
134 cvalue.v_pointer = instance;
135 error_msg = value_table->collect_value (value, nth_value++, &collect_type, &cvalue);
137 /* this shouldn't be triggered, instance types should collect just one pointer,
138 * but since we have to follow the calling conventions for collect_value(),
139 * we can attempt to feed them with 0s if they insist on extra args.
141 while (collect_type && !error_msg)
143 memset (&cvalue, 0, sizeof (cvalue));
144 error_msg = value_table->collect_value (value, nth_value++, &collect_type, &cvalue);
149 g_warning ("%s: %s", G_STRLOC, error_msg);
152 /* we purposely leak the value here, it might not be
153 * in a sane state if an error condition occoured
155 memset (value, 0, sizeof (*value));
156 value->g_type = g_type;
157 value_table->value_init (value);
163 g_value_unset (GValue *value)
165 GTypeValueTable *value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
167 g_return_if_fail (G_IS_VALUE (value));
169 g_return_if_fail (g_type_value_table_peek (G_VALUE_TYPE (value)) != NULL);
171 if (value_table->value_free)
172 value_table->value_free (value);
173 memset (value, 0, sizeof (*value));
177 g_value_reset (GValue *value)
179 GTypeValueTable *value_table;
182 g_return_if_fail (G_IS_VALUE (value));
184 value_table = g_type_value_table_peek (G_VALUE_TYPE (value));
185 g_type = G_VALUE_TYPE (value);
187 if (value_table->value_free)
188 value_table->value_free (value);
189 memset (value, 0, sizeof (*value));
191 value->g_type = g_type;
192 value_table->value_init (value);
196 exchange_entries_equal (gconstpointer v1,
199 const ExchangeEntry *entry1 = v1;
200 const ExchangeEntry *entry2 = v2;
202 return (entry1->value_type1 == entry2->value_type1 &&
203 entry1->value_type2 == entry2->value_type2);
207 exchange_entry_hash (gconstpointer key)
209 const ExchangeEntry *entry = key;
211 return entry->value_type1 ^ entry->value_type2;
215 value_exchange_memcpy (GValue *value1,
220 memcpy (&tmp_value.data, &value1->data, sizeof (value1->data));
221 memcpy (&value1->data, &value2->data, sizeof (value1->data));
222 memcpy (&value2->data, &tmp_value.data, sizeof (value2->data));
225 static inline GValueExchange
226 exchange_func_lookup (GType value_type1,
230 if (value_type1 == value_type2)
231 return value_exchange_memcpy;
234 GType type1 = value_type1;
238 GType type2 = value_type2;
242 ExchangeEntry entry, *ret;
244 entry.value_type1 = MIN (type1, type2);
245 entry.value_type2 = MAX (type1, type2);
246 ret = g_hash_table_lookup (param_exchange_ht, &entry);
250 *need_swap = ret->first_type == type2;
255 type2 = g_type_parent (type2);
259 type1 = g_type_parent (type1);
268 g_value_register_exchange_func (GType value_type1,
274 g_return_if_fail (g_type_name (value_type1) != NULL);
275 g_return_if_fail (g_type_name (value_type2) != NULL);
276 g_return_if_fail (func != NULL);
278 entry.value_type1 = MIN (value_type1, value_type2);
279 entry.value_type2 = MAX (value_type1, value_type2);
280 if (param_exchange_ht && g_hash_table_lookup (param_exchange_ht, &entry))
281 g_warning (G_STRLOC ": cannot re-register param value exchange function "
283 g_type_name (value_type1),
284 g_type_name (value_type2));
287 ExchangeEntry *entry = g_new (ExchangeEntry, 1);
289 if (!param_exchange_ht)
290 param_exchange_ht = g_hash_table_new (exchange_entry_hash, exchange_entries_equal);
291 entry->value_type1 = MIN (value_type1, value_type2);
292 entry->value_type2 = MAX (value_type1, value_type2);
294 entry->first_type = value_type1;
295 g_hash_table_insert (param_exchange_ht, entry, entry);
300 g_value_types_exchangable (GType value_type1,
303 g_return_val_if_fail (G_TYPE_IS_VALUE (value_type1), FALSE); /* these might bite us, think G_TYPE_ENUM */
304 g_return_val_if_fail (G_TYPE_IS_VALUE (value_type2), FALSE);
306 return exchange_func_lookup (value_type1, value_type2, NULL) != NULL;
310 g_values_exchange (GValue *value1,
313 g_return_val_if_fail (G_IS_VALUE (value1), FALSE);
314 g_return_val_if_fail (G_IS_VALUE (value2), FALSE);
316 if (value1 != value2)
319 GValueExchange value_exchange = exchange_func_lookup (G_VALUE_TYPE (value1),
320 G_VALUE_TYPE (value2),
325 value_exchange (value2, value1);
327 value_exchange (value1, value2);
330 return value_exchange != NULL;
337 g_value_convert (const GValue *src_value,
340 gboolean success = TRUE;
342 g_return_val_if_fail (G_IS_VALUE (src_value), FALSE);
343 g_return_val_if_fail (G_IS_VALUE (dest_value), FALSE);
345 if (src_value != dest_value)
347 GValue tmp_value = { 0, };
349 g_value_init (&tmp_value, G_VALUE_TYPE (src_value));
350 g_value_copy (src_value, &tmp_value);
352 success = g_values_exchange (&tmp_value, dest_value);
353 g_value_unset (&tmp_value);