gobject/genums.c

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
   3  *
   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.
   8  *
   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.
  13  *
  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.
  18  */
  19
  20 /*
  21  * MT safe
  22  */
  23
  24 #include "config.h"
  25
  26 #include <string.h>
  27
  28 #include "genums.h"
  29 #include "gvalue.h"
  30 #include "gvaluecollector.h"
  31 #include "gobjectalias.h"
  32
  33
  34 /**
  35  * SECTION:enumerations_flags
  36  * @short_description: Enumeration and flags types
  37  * @see_also:#GParamSpecEnum, #GParamSpecFlags, g_param_spec_enum(),
  38  * g_param_spec_flags(),
  39  *
  40  * <link linkend="glib-mkenums">glib-mkenums</link>
  41  * @title: Enumeration and Flag Types
  42  *
  43  * The GLib type system provides fundamental types for enumeration and
  44  * flags types. (Flags types are like enumerations, but allow their
  45  * values to be combined by bitwise or). A registered enumeration or
  46  * flags type associates a name and a nickname with each allowed
  47  * value, and the methods g_enum_get_value_by_name(),
  48  * g_enum_get_value_by_nick(), g_flags_get_value_by_name() and
  49  * g_flags_get_value_by_nick() can look up values by their name or
  50  * nickname.  When an enumeration or flags type is registered with the
  51  * GLib type system, it can be used as value type for object
  52  * properties, using g_param_spec_enum() or g_param_spec_flags().
  53  *
  54  * GObject ships with a utility called <link
  55  * linkend="glib-mkenums">glib-mkenums</link> that can construct
  56  * suitable type registration functions from C enumeration
  57  * definitions.
  58  */
  59
  60
  61 /* --- prototypes --- */
  62 static void     g_enum_class_init               (GEnumClass     *class,
  63                                                  gpointer        class_data);
  64 static void     g_flags_class_init              (GFlagsClass    *class,
  65                                                  gpointer        class_data);
  66 static void     value_flags_enum_init           (GValue         *value);
  67 static void     value_flags_enum_copy_value     (const GValue   *src_value,
  68                                                  GValue         *dest_value);
  69 static gchar*   value_flags_enum_collect_value  (GValue         *value,
  70                                                  guint           n_collect_values,
  71                                                  GTypeCValue    *collect_values,
  72                                                  guint           collect_flags);
  73 static gchar*   value_flags_enum_lcopy_value    (const GValue   *value,
  74                                                  guint           n_collect_values,
  75                                                  GTypeCValue    *collect_values,
  76                                                  guint           collect_flags);
  77
  78 /* --- functions --- */
  79 void
  80 g_enum_types_init (void)
  81 {
  82   static gboolean initialized = FALSE;
  83   static const GTypeValueTable flags_enum_value_table = {
  84     value_flags_enum_init,          /* value_init */
  85     NULL,                           /* value_free */
  86     value_flags_enum_copy_value,    /* value_copy */
  87     NULL,                           /* value_peek_pointer */
  88     "i",                            /* collect_format */
  89     value_flags_enum_collect_value, /* collect_value */
  90     "p",                            /* lcopy_format */
  91     value_flags_enum_lcopy_value,   /* lcopy_value */
  92   };
  93   static GTypeInfo info = {
  94     0,                          /* class_size */
  95     NULL,                       /* base_init */
  96     NULL,                       /* base_destroy */
  97     NULL,                       /* class_init */
  98     NULL,                       /* class_destroy */
  99     NULL,                       /* class_data */
 100     0,                          /* instance_size */
 101     0,                          /* n_preallocs */
 102     NULL,                       /* instance_init */
 103     &flags_enum_value_table,    /* value_table */
 104   };
 105   static const GTypeFundamentalInfo finfo = {
 106     G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_DERIVABLE,
 107   };
 108   GType type;
 109
 110   g_return_if_fail (initialized == FALSE);
 111   initialized = TRUE;
 112
 113   /* G_TYPE_ENUM
 114    */
 115   info.class_size = sizeof (GEnumClass);
 116   type = g_type_register_fundamental (G_TYPE_ENUM, g_intern_static_string ("GEnum"), &info, &finfo,
 117                                       G_TYPE_FLAG_ABSTRACT | G_TYPE_FLAG_VALUE_ABSTRACT);
 118   g_assert (type == G_TYPE_ENUM);
 119
 120   /* G_TYPE_FLAGS
 121    */
 122   info.class_size = sizeof (GFlagsClass);
 123   type = g_type_register_fundamental (G_TYPE_FLAGS, g_intern_static_string ("GFlags"), &info, &finfo,
 124                                       G_TYPE_FLAG_ABSTRACT | G_TYPE_FLAG_VALUE_ABSTRACT);
 125   g_assert (type == G_TYPE_FLAGS);
 126 }
 127
 128 static void
 129 value_flags_enum_init (GValue *value)
 130 {
 131   value->data[0].v_long = 0;
 132 }
 133
 134 static void
 135 value_flags_enum_copy_value (const GValue *src_value,
 136                              GValue       *dest_value)
 137 {
 138   dest_value->data[0].v_long = src_value->data[0].v_long;
 139 }
 140
 141 static gchar*
 142 value_flags_enum_collect_value (GValue      *value,
 143                                 guint        n_collect_values,
 144                                 GTypeCValue *collect_values,
 145                                 guint        collect_flags)
 146 {
 147   value->data[0].v_long = collect_values[0].v_int;
 148
 149   return NULL;
 150 }
 151
 152 static gchar*
 153 value_flags_enum_lcopy_value (const GValue *value,
 154                               guint         n_collect_values,
 155                               GTypeCValue  *collect_values,
 156                               guint         collect_flags)
 157 {
 158   gint *int_p = collect_values[0].v_pointer;
 159
 160   if (!int_p)
 161     return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
 162
 163   *int_p = value->data[0].v_long;
 164
 165   return NULL;
 166 }
 167
 168 /**
 169  * g_enum_register_static:
 170  * @name: A nul-terminated string used as the name of the new type.
 171  * @const_static_values: An array of #GEnumValue structs for the possible
 172  *  enumeration values. The array is terminated by a struct with all
 173  *  members being 0. GObject keeps a reference to the data, so it cannot
 174  *  be stack-allocated.
 175  *
 176  * Registers a new static enumeration type with the name @name.
 177  *
 178  * It is normally more convenient to let <link
 179  * linkend="glib-mkenums">glib-mkenums</link> generate a
 180  * my_enum_get_type() function from a usual C enumeration definition
 181  * than to write one yourself using g_enum_register_static().
 182  *
 183  * Returns: The new type identifier.
 184  */
 185 GType
 186 g_enum_register_static (const gchar      *name,
 187                         const GEnumValue *const_static_values)
 188 {
 189   GTypeInfo enum_type_info = {
 190     sizeof (GEnumClass), /* class_size */
 191     NULL,                /* base_init */
 192     NULL,                /* base_finalize */
 193     (GClassInitFunc) g_enum_class_init,
 194     NULL,                /* class_finalize */
 195     NULL,                /* class_data */
 196     0,                   /* instance_size */
 197     0,                   /* n_preallocs */
 198     NULL,                /* instance_init */
 199     NULL,                /* value_table */
 200   };
 201   GType type;
 202
 203   g_return_val_if_fail (name != NULL, 0);
 204   g_return_val_if_fail (const_static_values != NULL, 0);
 205
 206   enum_type_info.class_data = const_static_values;
 207
 208   type = g_type_register_static (G_TYPE_ENUM, name, &enum_type_info, 0);
 209
 210   return type;
 211 }
 212
 213 /**
 214  * g_flags_register_static:
 215  * @name: A nul-terminated string used as the name of the new type.
 216  * @const_static_values: An array of #GFlagsValue structs for the possible
 217  *  flags values. The array is terminated by a struct with all members being 0.
 218  *  GObject keeps a reference to the data, so it cannot be stack-allocated.
 219  *
 220  * Registers a new static flags type with the name @name.
 221  *
 222  * It is normally more convenient to let <link
 223  * linkend="glib-mkenums">glib-mkenums</link> generate a
 224  * my_flags_get_type() function from a usual C enumeration definition
 225  * than to write one yourself using g_flags_register_static().
 226  *
 227  * Returns: The new type identifier.
 228  */
 229 GType
 230 g_flags_register_static (const gchar       *name,
 231                          const GFlagsValue *const_static_values)
 232 {
 233   GTypeInfo flags_type_info = {
 234     sizeof (GFlagsClass), /* class_size */
 235     NULL,                 /* base_init */
 236     NULL,                 /* base_finalize */
 237     (GClassInitFunc) g_flags_class_init,
 238     NULL,                 /* class_finalize */
 239     NULL,                 /* class_data */
 240     0,                    /* instance_size */
 241     0,                    /* n_preallocs */
 242     NULL,                 /* instance_init */
 243     NULL,                 /* value_table */
 244   };
 245   GType type;
 246
 247   g_return_val_if_fail (name != NULL, 0);
 248   g_return_val_if_fail (const_static_values != NULL, 0);
 249
 250   flags_type_info.class_data = const_static_values;
 251
 252   type = g_type_register_static (G_TYPE_FLAGS, name, &flags_type_info, 0);
 253
 254   return type;
 255 }
 256
 257 /**
 258  * g_enum_complete_type_info:
 259  * @g_enum_type: the type identifier of the type being completed
 260  * @info: the #GTypeInfo struct to be filled in
 261  * @const_values: An array of #GEnumValue structs for the possible
 262  *  enumeration values. The array is terminated by a struct with all
 263  *  members being 0.
 264  *
 265  * This function is meant to be called from the complete_type_info()
 266  * function of a #GTypePlugin implementation, as in the following
 267  * example:
 268  *
 269  * |[
 270  * static void
 271  * my_enum_complete_type_info (GTypePlugin     *plugin,
 272  *                             GType            g_type,
 273  *                             GTypeInfo       *info,
 274  *                             GTypeValueTable *value_table)
 275  * {
 276  *   static const GEnumValue values[] = {
 277  *     { MY_ENUM_FOO, "MY_ENUM_FOO", "foo" },
 278  *     { MY_ENUM_BAR, "MY_ENUM_BAR", "bar" },
 279  *     { 0, NULL, NULL }
 280  *   };
 281  *
 282  *   g_enum_complete_type_info (type, info, values);
 283  * }
 284  * ]|
 285  */
 286 void
 287 g_enum_complete_type_info (GType             g_enum_type,
 288                            GTypeInfo        *info,
 289                            const GEnumValue *const_values)
 290 {
 291   g_return_if_fail (G_TYPE_IS_ENUM (g_enum_type));
 292   g_return_if_fail (info != NULL);
 293   g_return_if_fail (const_values != NULL);
 294
 295   info->class_size = sizeof (GEnumClass);
 296   info->base_init = NULL;
 297   info->base_finalize = NULL;
 298   info->class_init = (GClassInitFunc) g_enum_class_init;
 299   info->class_finalize = NULL;
 300   info->class_data = const_values;
 301 }
 302
 303 /**
 304  * g_flags_complete_type_info:
 305  * @g_flags_type: the type identifier of the type being completed
 306  * @info: the #GTypeInfo struct to be filled in
 307  * @const_values: An array of #GFlagsValue structs for the possible
 308  *  enumeration values. The array is terminated by a struct with all
 309  *  members being 0.
 310  *
 311  * This function is meant to be called from the complete_type_info()
 312  * function of a #GTypePlugin implementation, see the example for
 313  * g_enum_complete_type_info() above.
 314  */
 315 void
 316 g_flags_complete_type_info (GType              g_flags_type,
 317                             GTypeInfo         *info,
 318                             const GFlagsValue *const_values)
 319 {
 320   g_return_if_fail (G_TYPE_IS_FLAGS (g_flags_type));
 321   g_return_if_fail (info != NULL);
 322   g_return_if_fail (const_values != NULL);
 323
 324   info->class_size = sizeof (GFlagsClass);
 325   info->base_init = NULL;
 326   info->base_finalize = NULL;
 327   info->class_init = (GClassInitFunc) g_flags_class_init;
 328   info->class_finalize = NULL;
 329   info->class_data = const_values;
 330 }
 331
 332 static void
 333 g_enum_class_init (GEnumClass *class,
 334                    gpointer    class_data)
 335 {
 336   g_return_if_fail (G_IS_ENUM_CLASS (class));
 337
 338   class->minimum = 0;
 339   class->maximum = 0;
 340   class->n_values = 0;
 341   class->values = class_data;
 342
 343   if (class->values)
 344     {
 345       GEnumValue *values;
 346
 347       class->minimum = class->values->value;
 348       class->maximum = class->values->value;
 349       for (values = class->values; values->value_name; values++)
 350         {
 351           class->minimum = MIN (class->minimum, values->value);
 352           class->maximum = MAX (class->maximum, values->value);
 353           class->n_values++;
 354         }
 355     }
 356 }
 357
 358 static void
 359 g_flags_class_init (GFlagsClass *class,
 360                     gpointer     class_data)
 361 {
 362   g_return_if_fail (G_IS_FLAGS_CLASS (class));
 363
 364   class->mask = 0;
 365   class->n_values = 0;
 366   class->values = class_data;
 367
 368   if (class->values)
 369     {
 370       GFlagsValue *values;
 371
 372       for (values = class->values; values->value_name; values++)
 373         {
 374           class->mask |= values->value;
 375           class->n_values++;
 376         }
 377     }
 378 }
 379
 380 /**
 381  * g_enum_get_value_by_name:
 382  * @enum_class: a #GEnumClass
 383  * @name: the name to look up
 384  *
 385  * Looks up a #GEnumValue by name.
 386  *
 387  * Returns: the #GEnumValue with name @name, or %NULL if the
 388  *          enumeration doesn't have a member with that name
 389  */
 390 GEnumValue*
 391 g_enum_get_value_by_name (GEnumClass  *enum_class,
 392                           const gchar *name)
 393 {
 394   g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
 395   g_return_val_if_fail (name != NULL, NULL);
 396
 397   if (enum_class->n_values)
 398     {
 399       GEnumValue *enum_value;
 400
 401       for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
 402         if (strcmp (name, enum_value->value_name) == 0)
 403           return enum_value;
 404     }
 405
 406   return NULL;
 407 }
 408
 409 /**
 410  * g_flags_get_value_by_name:
 411  * @flags_class: a #GFlagsClass
 412  * @name: the name to look up
 413  *
 414  * Looks up a #GFlagsValue by name.
 415  *
 416  * Returns: the #GFlagsValue with name @name, or %NULL if there is no
 417  *          flag with that name
 418  */
 419 GFlagsValue*
 420 g_flags_get_value_by_name (GFlagsClass *flags_class,
 421                            const gchar *name)
 422 {
 423   g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
 424   g_return_val_if_fail (name != NULL, NULL);
 425
 426   if (flags_class->n_values)
 427     {
 428       GFlagsValue *flags_value;
 429
 430       for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
 431         if (strcmp (name, flags_value->value_name) == 0)
 432           return flags_value;
 433     }
 434
 435   return NULL;
 436 }
 437
 438 /**
 439  * g_enum_get_value_by_nick:
 440  * @enum_class: a #GEnumClass
 441  * @nick: the nickname to look up
 442  *
 443  * Looks up a #GEnumValue by nickname.
 444  *
 445  * Returns: the #GEnumValue with nickname @nick, or %NULL if the
 446  *          enumeration doesn't have a member with that nickname
 447  */
 448 GEnumValue*
 449 g_enum_get_value_by_nick (GEnumClass  *enum_class,
 450                           const gchar *nick)
 451 {
 452   g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
 453   g_return_val_if_fail (nick != NULL, NULL);
 454
 455   if (enum_class->n_values)
 456     {
 457       GEnumValue *enum_value;
 458
 459       for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
 460         if (enum_value->value_nick && strcmp (nick, enum_value->value_nick) == 0)
 461           return enum_value;
 462     }
 463
 464   return NULL;
 465 }
 466
 467 /**
 468  * g_flags_get_value_by_nick:
 469  * @flags_class: a #GFlagsClass
 470  * @nick: the nickname to look up
 471  *
 472  * Looks up a #GFlagsValue by nickname.
 473  *
 474  * Returns: the #GFlagsValue with nickname @nick, or %NULL if there is
 475  *          no flag with that nickname
 476  */
 477 GFlagsValue*
 478 g_flags_get_value_by_nick (GFlagsClass *flags_class,
 479                            const gchar *nick)
 480 {
 481   g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
 482   g_return_val_if_fail (nick != NULL, NULL);
 483
 484   if (flags_class->n_values)
 485     {
 486       GFlagsValue *flags_value;
 487
 488       for (flags_value = flags_class->values; flags_value->value_nick; flags_value++)
 489         if (flags_value->value_nick && strcmp (nick, flags_value->value_nick) == 0)
 490           return flags_value;
 491     }
 492
 493   return NULL;
 494 }
 495
 496 /**
 497  * g_enum_get_value:
 498  * @enum_class: a #GEnumClass
 499  * @value: the value to look up
 500  *
 501  * Returns the #GEnumValue for a value.
 502  *
 503  * Returns: the #GEnumValue for @value, or %NULL if @value is not a
 504  *          member of the enumeration
 505  */
 506 GEnumValue*
 507 g_enum_get_value (GEnumClass *enum_class,
 508                   gint        value)
 509 {
 510   g_return_val_if_fail (G_IS_ENUM_CLASS (enum_class), NULL);
 511
 512   if (enum_class->n_values)
 513     {
 514       GEnumValue *enum_value;
 515
 516       for (enum_value = enum_class->values; enum_value->value_name; enum_value++)
 517         if (enum_value->value == value)
 518           return enum_value;
 519     }
 520
 521   return NULL;
 522 }
 523
 524 /**
 525  * g_flags_get_first_value:
 526  * @flags_class: a #GFlagsClass
 527  * @value: the value
 528  *
 529  * Returns the first #GFlagsValue which is set in @value.
 530  *
 531  * Returns: the first #GFlagsValue which is set in @value, or %NULL if
 532  *          none is set
 533  */
 534 GFlagsValue*
 535 g_flags_get_first_value (GFlagsClass *flags_class,
 536                          guint        value)
 537 {
 538   g_return_val_if_fail (G_IS_FLAGS_CLASS (flags_class), NULL);
 539
 540   if (flags_class->n_values)
 541     {
 542       GFlagsValue *flags_value;
 543
 544       if (value == 0)
 545         {
 546           for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
 547             if (flags_value->value == 0)
 548               return flags_value;
 549         }
 550       else
 551         {
 552           for (flags_value = flags_class->values; flags_value->value_name; flags_value++)
 553             if (flags_value->value != 0 && (flags_value->value & value) == flags_value->value)
 554               return flags_value;
 555         }
 556     }
 557
 558   return NULL;
 559 }
 560
 561 /**
 562  * g_value_set_enum:
 563  * @value: a valid #GValue whose type is derived from %G_TYPE_ENUM
 564  * @v_enum: enum value to be set
 565  *
 566  * Set the contents of a %G_TYPE_ENUM #GValue to @v_enum.
 567  */
 568 void
 569 g_value_set_enum (GValue *value,
 570                   gint    v_enum)
 571 {
 572   g_return_if_fail (G_VALUE_HOLDS_ENUM (value));
 573
 574   value->data[0].v_long = v_enum;
 575 }
 576
 577 /**
 578  * g_value_get_enum:
 579  * @value: a valid #GValue whose type is derived from %G_TYPE_ENUM
 580  *
 581  * Get the contents of a %G_TYPE_ENUM #GValue.
 582  *
 583  * Returns: enum contents of @value
 584  */
 585 gint
 586 g_value_get_enum (const GValue *value)
 587 {
 588   g_return_val_if_fail (G_VALUE_HOLDS_ENUM (value), 0);
 589
 590   return value->data[0].v_long;
 591 }
 592
 593 /**
 594  * g_value_set_flags:
 595  * @value: a valid #GValue whose type is derived from %G_TYPE_FLAGS
 596  * @v_flags: flags value to be set
 597  *
 598  * Set the contents of a %G_TYPE_FLAGS #GValue to @v_flags.
 599  */
 600 void
 601 g_value_set_flags (GValue *value,
 602                    guint   v_flags)
 603 {
 604   g_return_if_fail (G_VALUE_HOLDS_FLAGS (value));
 605
 606   value->data[0].v_ulong = v_flags;
 607 }
 608
 609 /**
 610  * g_value_get_flags:
 611  * @value: a valid #GValue whose type is derived from %G_TYPE_FLAGS
 612  *
 613  * Get the contents of a %G_TYPE_FLAGS #GValue.
 614  *
 615  * Returns: flags contents of @value
 616  */
 617 guint
 618 g_value_get_flags (const GValue *value)
 619 {
 620   g_return_val_if_fail (G_VALUE_HOLDS_FLAGS (value), 0);
 621
 622   return value->data[0].v_ulong;
 623 }
 624
 625 #define __G_ENUMS_C__
 626 #include "gobjectaliasdef.c"