gio/gicon.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright (C) 2006-2007 Red Hat, Inc.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  *
  20  * Author: Alexander Larsson <alexl@redhat.com>
  21  */
  22
  23 #include "config.h"
  24 #include <stdlib.h>
  25 #include <string.h>
  26
  27 #include "gicon.h"
  28 #include "gthemedicon.h"
  29 #include "gfileicon.h"
  30 #include "gemblemedicon.h"
  31 #include "gfile.h"
  32 #include "gioerror.h"
  33
  34 #include "glibintl.h"
  35
  36
  37 /* There versioning of this is implicit, version 1 would be ".1 " */
  38 #define G_ICON_SERIALIZATION_MAGIC0 ". "
  39
  40 /**
  41  * SECTION:gicon
  42  * @short_description: Interface for icons
  43  * @include: gio/gio.h
  44  *
  45  * #GIcon is a very minimal interface for icons. It provides functions
  46  * for checking the equality of two icons, hashing of icons and
  47  * serializing an icon to and from strings.
  48  *
  49  * #GIcon does not provide the actual pixmap for the icon as this is out
  50  * of GIO's scope, however implementations of #GIcon may contain the name
  51  * of an icon (see #GThemedIcon), or the path to an icon (see #GLoadableIcon).
  52  *
  53  * To obtain a hash of a #GIcon, see g_icon_hash().
  54  *
  55  * To check if two #GIcons are equal, see g_icon_equal().
  56  *
  57  * For serializing a #GIcon, use g_icon_to_string() and
  58  * g_icon_new_for_string().
  59  *
  60  * If your application or library provides one or more #GIcon
  61  * implementations you need to ensure that each #GType is registered
  62  * with the type system prior to calling g_icon_new_for_string().
  63  **/
  64
  65 typedef GIconIface GIconInterface;
  66 G_DEFINE_INTERFACE(GIcon, g_icon, G_TYPE_OBJECT)
  67
  68 static void
  69 g_icon_default_init (GIconInterface *iface)
  70 {
  71 }
  72
  73 /**
  74  * g_icon_hash:
  75  * @icon: #gconstpointer to an icon object.
  76  *
  77  * Gets a hash for an icon.
  78  *
  79  * Virtual: hash
  80  * Returns: a #guint containing a hash for the @icon, suitable for
  81  * use in a #GHashTable or similar data structure.
  82  **/
  83 guint
  84 g_icon_hash (gconstpointer icon)
  85 {
  86   GIconIface *iface;
  87
  88   g_return_val_if_fail (G_IS_ICON (icon), 0);
  89
  90   iface = G_ICON_GET_IFACE (icon);
  91
  92   return (* iface->hash) ((GIcon *)icon);
  93 }
  94
  95 /**
  96  * g_icon_equal:
  97  * @icon1: (allow-none): pointer to the first #GIcon.
  98  * @icon2: (allow-none): pointer to the second #GIcon.
  99  *
 100  * Checks if two icons are equal.
 101  *
 102  * Returns: %TRUE if @icon1 is equal to @icon2. %FALSE otherwise.
 103  **/
 104 gboolean
 105 g_icon_equal (GIcon *icon1,
 106               GIcon *icon2)
 107 {
 108   GIconIface *iface;
 109
 110   if (icon1 == NULL && icon2 == NULL)
 111     return TRUE;
 112
 113   if (icon1 == NULL || icon2 == NULL)
 114     return FALSE;
 115
 116   if (G_TYPE_FROM_INSTANCE (icon1) != G_TYPE_FROM_INSTANCE (icon2))
 117     return FALSE;
 118
 119   iface = G_ICON_GET_IFACE (icon1);
 120
 121   return (* iface->equal) (icon1, icon2);
 122 }
 123
 124 static gboolean
 125 g_icon_to_string_tokenized (GIcon *icon, GString *s)
 126 {
 127   GPtrArray *tokens;
 128   gint version;
 129   GIconIface *icon_iface;
 130   int i;
 131
 132   g_return_val_if_fail (icon != NULL, FALSE);
 133   g_return_val_if_fail (G_IS_ICON (icon), FALSE);
 134
 135   icon_iface = G_ICON_GET_IFACE (icon);
 136   if (icon_iface->to_tokens == NULL)
 137     return FALSE;
 138
 139   tokens = g_ptr_array_new ();
 140   if (!icon_iface->to_tokens (icon, tokens, &version))
 141     {
 142       g_ptr_array_free (tokens, TRUE);
 143       return FALSE;
 144     }
 145
 146   /* format: TypeName[.Version] <token_0> .. <token_N-1>
 147      version 0 is implicit and can be omitted
 148      all the tokens are url escaped to ensure they have no spaces in them */
 149
 150   g_string_append (s, g_type_name_from_instance ((GTypeInstance *)icon));
 151   if (version != 0)
 152     g_string_append_printf (s, ".%d", version);
 153
 154   for (i = 0; i < tokens->len; i++)
 155     {
 156       char *token;
 157
 158       token = g_ptr_array_index (tokens, i);
 159
 160       g_string_append_c (s, ' ');
 161       /* We really only need to escape spaces here, so allow lots of otherwise reserved chars */
 162       g_string_append_uri_escaped (s, token,
 163                                    G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
 164
 165       g_free (token);
 166     }
 167
 168   g_ptr_array_free (tokens, TRUE);
 169
 170   return TRUE;
 171 }
 172
 173 /**
 174  * g_icon_to_string:
 175  * @icon: a #GIcon.
 176  *
 177  * Generates a textual representation of @icon that can be used for
 178  * serialization such as when passing @icon to a different process or
 179  * saving it to persistent storage. Use g_icon_new_for_string() to
 180  * get @icon back from the returned string.
 181  *
 182  * The encoding of the returned string is proprietary to #GIcon except
 183  * in the following two cases
 184  *
 185  * <itemizedlist>
 186  * <listitem><para>
 187  *     If @icon is a #GFileIcon, the returned string is a native path
 188  *     (such as <literal>/path/to/my icon.png</literal>) without escaping
 189  *     if the #GFile for @icon is a native file.  If the file is not
 190  *     native, the returned string is the result of g_file_get_uri()
 191  *     (such as <literal>sftp://path/to/my&percnt;20icon.png</literal>).
 192  * </para></listitem>
 193  * <listitem><para>
 194  *    If @icon is a #GThemedIcon with exactly one name, the encoding is
 195  *    simply the name (such as <literal>network-server</literal>).
 196  * </para></listitem>
 197  * </itemizedlist>
 198  *
 199  * Virtual: to_tokens
 200  * Returns: An allocated NUL-terminated UTF8 string or %NULL if @icon can't
 201  * be serialized. Use g_free() to free.
 202  *
 203  * Since: 2.20
 204  */
 205 gchar *
 206 g_icon_to_string (GIcon *icon)
 207 {
 208   gchar *ret;
 209
 210   g_return_val_if_fail (icon != NULL, NULL);
 211   g_return_val_if_fail (G_IS_ICON (icon), NULL);
 212
 213   ret = NULL;
 214
 215   if (G_IS_FILE_ICON (icon))
 216     {
 217       GFile *file;
 218
 219       file = g_file_icon_get_file (G_FILE_ICON (icon));
 220       if (g_file_is_native (file))
 221         {
 222           ret = g_file_get_path (file);
 223           if (!g_utf8_validate (ret, -1, NULL))
 224             {
 225               g_free (ret);
 226               ret = NULL;
 227             }
 228         }
 229       else
 230         ret = g_file_get_uri (file);
 231     }
 232   else if (G_IS_THEMED_ICON (icon))
 233     {
 234       const char * const *names;
 235
 236       names = g_themed_icon_get_names (G_THEMED_ICON (icon));
 237       if (names != NULL &&
 238           names[0] != NULL &&
 239           names[0][0] != '.' && /* Allowing icons starting with dot would break G_ICON_SERIALIZATION_MAGIC0 */
 240           g_utf8_validate (names[0], -1, NULL) && /* Only return utf8 strings */
 241           names[1] == NULL)
 242         ret = g_strdup (names[0]);
 243     }
 244
 245   if (ret == NULL)
 246     {
 247       GString *s;
 248
 249       s = g_string_new (G_ICON_SERIALIZATION_MAGIC0);
 250
 251       if (g_icon_to_string_tokenized (icon, s))
 252         ret = g_string_free (s, FALSE);
 253       else
 254         g_string_free (s, TRUE);
 255     }
 256
 257   return ret;
 258 }
 259
 260 static GIcon *
 261 g_icon_new_from_tokens (char   **tokens,
 262                         GError **error)
 263 {
 264   GIcon *icon;
 265   char *typename, *version_str;
 266   GType type;
 267   gpointer klass;
 268   GIconIface *icon_iface;
 269   gint version;
 270   char *endp;
 271   int num_tokens;
 272   int i;
 273
 274   icon = NULL;
 275   klass = NULL;
 276
 277   num_tokens = g_strv_length (tokens);
 278
 279   if (num_tokens < 1)
 280     {
 281       g_set_error (error,
 282                    G_IO_ERROR,
 283                    G_IO_ERROR_INVALID_ARGUMENT,
 284                    _("Wrong number of tokens (%d)"),
 285                    num_tokens);
 286       goto out;
 287     }
 288
 289   typename = tokens[0];
 290   version_str = strchr (typename, '.');
 291   if (version_str)
 292     {
 293       *version_str = 0;
 294       version_str += 1;
 295     }
 296
 297
 298   type = g_type_from_name (tokens[0]);
 299   if (type == 0)
 300     {
 301       g_set_error (error,
 302                    G_IO_ERROR,
 303                    G_IO_ERROR_INVALID_ARGUMENT,
 304                    _("No type for class name %s"),
 305                    tokens[0]);
 306       goto out;
 307     }
 308
 309   if (!g_type_is_a (type, G_TYPE_ICON))
 310     {
 311       g_set_error (error,
 312                    G_IO_ERROR,
 313                    G_IO_ERROR_INVALID_ARGUMENT,
 314                    _("Type %s does not implement the GIcon interface"),
 315                    tokens[0]);
 316       goto out;
 317     }
 318
 319   klass = g_type_class_ref (type);
 320   if (klass == NULL)
 321     {
 322       g_set_error (error,
 323                    G_IO_ERROR,
 324                    G_IO_ERROR_INVALID_ARGUMENT,
 325                    _("Type %s is not classed"),
 326                    tokens[0]);
 327       goto out;
 328     }
 329
 330   version = 0;
 331   if (version_str)
 332     {
 333       version = strtol (version_str, &endp, 10);
 334       if (endp == NULL || *endp != '\0')
 335         {
 336           g_set_error (error,
 337                        G_IO_ERROR,
 338                        G_IO_ERROR_INVALID_ARGUMENT,
 339                        _("Malformed version number: %s"),
 340                        version_str);
 341           goto out;
 342         }
 343     }
 344
 345   icon_iface = g_type_interface_peek (klass, G_TYPE_ICON);
 346   g_assert (icon_iface != NULL);
 347
 348   if (icon_iface->from_tokens == NULL)
 349     {
 350       g_set_error (error,
 351                    G_IO_ERROR,
 352                    G_IO_ERROR_INVALID_ARGUMENT,
 353                    _("Type %s does not implement from_tokens() on the GIcon interface"),
 354                    tokens[0]);
 355       goto out;
 356     }
 357
 358   for (i = 1;  i < num_tokens; i++)
 359     {
 360       char *escaped;
 361
 362       escaped = tokens[i];
 363       tokens[i] = g_uri_unescape_string (escaped, NULL);
 364       g_free (escaped);
 365     }
 366
 367   icon = icon_iface->from_tokens (tokens + 1, num_tokens - 1, version, error);
 368
 369  out:
 370   if (klass != NULL)
 371     g_type_class_unref (klass);
 372   return icon;
 373 }
 374
 375 static void
 376 ensure_builtin_icon_types (void)
 377 {
 378   g_type_ensure (G_TYPE_THEMED_ICON);
 379   g_type_ensure (G_TYPE_FILE_ICON);
 380   g_type_ensure (G_TYPE_EMBLEMED_ICON);
 381   g_type_ensure (G_TYPE_EMBLEM);
 382 }
 383
 384 /**
 385  * g_icon_new_for_string:
 386  * @str: A string obtained via g_icon_to_string().
 387  * @error: Return location for error.
 388  *
 389  * Generate a #GIcon instance from @str. This function can fail if
 390  * @str is not valid - see g_icon_to_string() for discussion.
 391  *
 392  * If your application or library provides one or more #GIcon
 393  * implementations you need to ensure that each #GType is registered
 394  * with the type system prior to calling g_icon_new_for_string().
 395  *
 396  * Returns: (transfer full): An object implementing the #GIcon
 397  *          interface or %NULL if @error is set.
 398  *
 399  * Since: 2.20
 400  **/
 401 GIcon *
 402 g_icon_new_for_string (const gchar   *str,
 403                        GError       **error)
 404 {
 405   GIcon *icon;
 406
 407   g_return_val_if_fail (str != NULL, NULL);
 408
 409   ensure_builtin_icon_types ();
 410
 411   icon = NULL;
 412
 413   if (*str == '.')
 414     {
 415       if (g_str_has_prefix (str, G_ICON_SERIALIZATION_MAGIC0))
 416         {
 417           gchar **tokens;
 418
 419           /* handle tokenized encoding */
 420           tokens = g_strsplit (str + sizeof (G_ICON_SERIALIZATION_MAGIC0) - 1, " ", 0);
 421           icon = g_icon_new_from_tokens (tokens, error);
 422           g_strfreev (tokens);
 423         }
 424       else
 425         g_set_error_literal (error,
 426                              G_IO_ERROR,
 427                              G_IO_ERROR_INVALID_ARGUMENT,
 428                              _("Can't handle the supplied version of the icon encoding"));
 429     }
 430   else
 431     {
 432       gchar *scheme;
 433
 434       /* handle special GFileIcon and GThemedIcon cases */
 435       scheme = g_uri_parse_scheme (str);
 436       if (scheme != NULL || str[0] == '/' || str[0] == G_DIR_SEPARATOR)
 437         {
 438           GFile *location;
 439           location = g_file_new_for_commandline_arg (str);
 440           icon = g_file_icon_new (location);
 441           g_object_unref (location);
 442         }
 443       else
 444         icon = g_themed_icon_new (str);
 445       g_free (scheme);
 446     }
 447
 448   return icon;
 449 }