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