(root)/
glib-2.79.0/
gio/
gicon.c
       1  /* GIO - GLib Input, Output and Streaming Library
       2   * 
       3   * Copyright (C) 2006-2007 Red Hat, Inc.
       4   *
       5   * SPDX-License-Identifier: LGPL-2.1-or-later
       6   *
       7   * This library is free software; you can redistribute it and/or
       8   * modify it under the terms of the GNU Lesser General Public
       9   * License as published by the Free Software Foundation; either
      10   * version 2.1 of the License, or (at your option) any later version.
      11   *
      12   * This library is distributed in the hope that it will be useful,
      13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
      14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      15   * Lesser General Public License for more details.
      16   *
      17   * You should have received a copy of the GNU Lesser General
      18   * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
      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 "gbytesicon.h"
      32  #include "gfile.h"
      33  #include "gioerror.h"
      34  #include "gioenumtypes.h"
      35  #include "gvfs.h"
      36  
      37  #include "glibintl.h"
      38  
      39  
      40  /* There versioning of this is implicit, version 1 would be ".1 " */
      41  #define G_ICON_SERIALIZATION_MAGIC0 ". "
      42  
      43  /**
      44   * GIcon:
      45   *
      46   * `GIcon` is a very minimal interface for icons. It provides functions
      47   * for checking the equality of two icons, hashing of icons and
      48   * serializing an icon to and from strings.
      49   *
      50   * `GIcon` does not provide the actual pixmap for the icon as this is out
      51   * of GIO's scope, however implementations of `GIcon` may contain the name
      52   * of an icon (see [class@Gio.ThemedIcon]), or the path to an icon
      53   * (see [iface@Gio.LoadableIcon]).
      54   *
      55   * To obtain a hash of a `GIcon`, see [method@Gio.Icon.hash].
      56   *
      57   * To check if two `GIcon`s are equal, see [method@Gio.Icon.equal].
      58   *
      59   * For serializing a `GIcon`, use [method@Gio.Icon.serialize] and
      60   * [func@Gio.Icon.deserialize].
      61   *
      62   * If you want to consume `GIcon` (for example, in a toolkit) you must
      63   * be prepared to handle at least the three following cases:
      64   * [iface@Gio.LoadableIcon], [class@Gio.ThemedIcon] and [class@Gio.EmblemedIcon].
      65   * It may also make sense to have fast-paths for other cases (like handling
      66   * [class@GdkPixbuf.Pixbuf] directly, for example) but all compliant `GIcon`
      67   * implementations outside of GIO must implement [iface@Gio.LoadableIcon].
      68   *
      69   * If your application or library provides one or more `GIcon`
      70   * implementations you need to ensure that your new implementation also
      71   * implements [iface@Gio.LoadableIcon].  Additionally, you must provide an
      72   * implementation of [method@Gio.Icon.serialize] that gives a result that is
      73   * understood by [func@Gio.Icon.deserialize], yielding one of the built-in
      74   * icon types.
      75   **/
      76  
      77  typedef GIconIface GIconInterface;
      78  G_DEFINE_INTERFACE(GIcon, g_icon, G_TYPE_OBJECT)
      79  
      80  static void
      81  g_icon_default_init (GIconInterface *iface)
      82  {
      83  }
      84  
      85  /**
      86   * g_icon_hash: (virtual hash)
      87   * @icon: (not nullable) (type Gio.Icon): #gconstpointer to an icon object.
      88   * 
      89   * Gets a hash for an icon.
      90   *
      91   * Returns: a #guint containing a hash for the @icon, suitable for 
      92   *   use in a #GHashTable or similar data structure.
      93   **/
      94  guint
      95  g_icon_hash (gconstpointer icon)
      96  {
      97    GIconIface *iface;
      98  
      99    g_return_val_if_fail (G_IS_ICON (icon), 0);
     100  
     101    iface = G_ICON_GET_IFACE (icon);
     102  
     103    return (* iface->hash) ((GIcon *)icon);
     104  }
     105  
     106  /**
     107   * g_icon_equal: (virtual equal)
     108   * @icon1: (nullable): pointer to the first #GIcon.
     109   * @icon2: (nullable): pointer to the second #GIcon.
     110   * 
     111   * Checks if two icons are equal.
     112   * 
     113   * Returns: %TRUE if @icon1 is equal to @icon2. %FALSE otherwise.
     114   **/
     115  gboolean
     116  g_icon_equal (GIcon *icon1,
     117  	      GIcon *icon2)
     118  {
     119    GIconIface *iface;
     120  
     121    if (icon1 == NULL && icon2 == NULL)
     122      return TRUE;
     123  
     124    if (icon1 == NULL || icon2 == NULL)
     125      return FALSE;
     126    
     127    if (G_TYPE_FROM_INSTANCE (icon1) != G_TYPE_FROM_INSTANCE (icon2))
     128      return FALSE;
     129  
     130    iface = G_ICON_GET_IFACE (icon1);
     131    
     132    return (* iface->equal) (icon1, icon2);
     133  }
     134  
     135  static gboolean
     136  g_icon_to_string_tokenized (GIcon *icon, GString *s)
     137  {
     138    GPtrArray *tokens;
     139    gint version;
     140    GIconIface *icon_iface;
     141    guint i;
     142  
     143    g_return_val_if_fail (icon != NULL, FALSE);
     144    g_return_val_if_fail (G_IS_ICON (icon), FALSE);
     145  
     146    icon_iface = G_ICON_GET_IFACE (icon);
     147    if (icon_iface->to_tokens == NULL)
     148      return FALSE;
     149  
     150    tokens = g_ptr_array_new ();
     151    if (!icon_iface->to_tokens (icon, tokens, &version))
     152      {
     153        g_ptr_array_free (tokens, TRUE);
     154        return FALSE;
     155      }
     156  
     157    /* format: TypeName[.Version] <token_0> .. <token_N-1>
     158       version 0 is implicit and can be omitted
     159       all the tokens are url escaped to ensure they have no spaces in them */
     160    
     161    g_string_append (s, g_type_name_from_instance ((GTypeInstance *)icon));
     162    if (version != 0)
     163      g_string_append_printf (s, ".%d", version);
     164    
     165    for (i = 0; i < tokens->len; i++)
     166      {
     167        char *token;
     168  
     169        token = g_ptr_array_index (tokens, i);
     170  
     171        g_string_append_c (s, ' ');
     172        /* We really only need to escape spaces here, so allow lots of otherwise reserved chars */
     173        g_string_append_uri_escaped (s, token,
     174  				   G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
     175  
     176        g_free (token);
     177      }
     178    
     179    g_ptr_array_free (tokens, TRUE);
     180    
     181    return TRUE;
     182  }
     183  
     184  /**
     185   * g_icon_to_string:
     186   * @icon: a #GIcon.
     187   *
     188   * Generates a textual representation of @icon that can be used for
     189   * serialization such as when passing @icon to a different process or
     190   * saving it to persistent storage. Use g_icon_new_for_string() to
     191   * get @icon back from the returned string.
     192   *
     193   * The encoding of the returned string is proprietary to #GIcon except
     194   * in the following two cases
     195   *
     196   * - If @icon is a #GFileIcon, the returned string is a native path
     197   *   (such as `/path/to/my icon.png`) without escaping
     198   *   if the #GFile for @icon is a native file.  If the file is not
     199   *   native, the returned string is the result of g_file_get_uri()
     200   *   (such as `sftp://path/to/my%20icon.png`).
     201   * 
     202   * - If @icon is a #GThemedIcon with exactly one name and no fallbacks,
     203   *   the encoding is simply the name (such as `network-server`).
     204   *
     205   * Returns: (nullable): An allocated NUL-terminated UTF8 string or
     206   * %NULL if @icon can't be serialized. Use g_free() to free.
     207   *
     208   * Since: 2.20
     209   */
     210  gchar *
     211  g_icon_to_string (GIcon *icon)
     212  {
     213    gchar *ret;
     214  
     215    g_return_val_if_fail (icon != NULL, NULL);
     216    g_return_val_if_fail (G_IS_ICON (icon), NULL);
     217  
     218    ret = NULL;
     219  
     220    if (G_IS_FILE_ICON (icon))
     221      {
     222        GFile *file;
     223  
     224        file = g_file_icon_get_file (G_FILE_ICON (icon));
     225        if (g_file_is_native (file))
     226  	{
     227  	  ret = g_file_get_path (file);
     228  	  if (!g_utf8_validate (ret, -1, NULL))
     229  	    {
     230  	      g_free (ret);
     231  	      ret = NULL;
     232  	    }
     233  	}
     234        else
     235          ret = g_file_get_uri (file);
     236      }
     237    else if (G_IS_THEMED_ICON (icon))
     238      {
     239        char     **names                 = NULL;
     240        gboolean   use_default_fallbacks = FALSE;
     241  
     242        g_object_get (G_OBJECT (icon),
     243                      "names",                 &names,
     244                      "use-default-fallbacks", &use_default_fallbacks,
     245                      NULL);
     246        /* Themed icon initialized with a single name and no fallbacks. */
     247        if (names != NULL &&
     248  	  names[0] != NULL &&
     249  	  names[0][0] != '.' && /* Allowing icons starting with dot would break G_ICON_SERIALIZATION_MAGIC0 */
     250  	  g_utf8_validate (names[0], -1, NULL) && /* Only return utf8 strings */
     251            names[1] == NULL &&
     252            ! use_default_fallbacks)
     253  	ret = g_strdup (names[0]);
     254  
     255        g_strfreev (names);
     256      }
     257  
     258    if (ret == NULL)
     259      {
     260        GString *s;
     261  
     262        s = g_string_new (G_ICON_SERIALIZATION_MAGIC0);
     263  
     264        if (g_icon_to_string_tokenized (icon, s))
     265  	ret = g_string_free (s, FALSE);
     266        else
     267  	g_string_free (s, TRUE);
     268      }
     269  
     270    return ret;
     271  }
     272  
     273  static GIcon *
     274  g_icon_new_from_tokens (char   **tokens,
     275  			GError **error)
     276  {
     277    GIcon *icon;
     278    char *typename, *version_str;
     279    GType type;
     280    gpointer klass;
     281    GIconIface *icon_iface;
     282    gint version;
     283    char *endp;
     284    int num_tokens;
     285    int i;
     286  
     287    icon = NULL;
     288    klass = NULL;
     289  
     290    num_tokens = g_strv_length (tokens);
     291  
     292    if (num_tokens < 1)
     293      {
     294        g_set_error (error,
     295                     G_IO_ERROR,
     296                     G_IO_ERROR_INVALID_ARGUMENT,
     297                     _("Wrong number of tokens (%d)"),
     298                     num_tokens);
     299        goto out;
     300      }
     301    
     302    typename = tokens[0];
     303    version_str = strchr (typename, '.');
     304    if (version_str)
     305      {
     306        *version_str = 0;
     307        version_str += 1;
     308      }
     309    
     310    
     311    type = g_type_from_name (tokens[0]);
     312    if (type == 0)
     313      {
     314        g_set_error (error,
     315                     G_IO_ERROR,
     316                     G_IO_ERROR_INVALID_ARGUMENT,
     317                     _("No type for class name %s"),
     318                     tokens[0]);
     319        goto out;
     320      }
     321  
     322    if (!g_type_is_a (type, G_TYPE_ICON))
     323      {
     324        g_set_error (error,
     325                     G_IO_ERROR,
     326                     G_IO_ERROR_INVALID_ARGUMENT,
     327                     _("Type %s does not implement the GIcon interface"),
     328                     tokens[0]);
     329        goto out;
     330      }
     331  
     332    klass = g_type_class_ref (type);
     333    if (klass == NULL)
     334      {
     335        g_set_error (error,
     336                     G_IO_ERROR,
     337                     G_IO_ERROR_INVALID_ARGUMENT,
     338                     _("Type %s is not classed"),
     339                     tokens[0]);
     340        goto out;
     341      }
     342  
     343    version = 0;
     344    if (version_str)
     345      {
     346        version = strtol (version_str, &endp, 10);
     347        if (endp == NULL || *endp != '\0')
     348  	{
     349  	  g_set_error (error,
     350  		       G_IO_ERROR,
     351  		       G_IO_ERROR_INVALID_ARGUMENT,
     352  		       _("Malformed version number: %s"),
     353  		       version_str);
     354  	  goto out;
     355  	}
     356      }
     357  
     358    icon_iface = g_type_interface_peek (klass, G_TYPE_ICON);
     359    g_assert (icon_iface != NULL);
     360  
     361    if (icon_iface->from_tokens == NULL)
     362      {
     363        g_set_error (error,
     364                     G_IO_ERROR,
     365                     G_IO_ERROR_INVALID_ARGUMENT,
     366                     _("Type %s does not implement from_tokens() on the GIcon interface"),
     367                     tokens[0]);
     368        goto out;
     369      }
     370  
     371    for (i = 1;  i < num_tokens; i++)
     372      {
     373        char *escaped;
     374  
     375        escaped = tokens[i];
     376        tokens[i] = g_uri_unescape_string (escaped, NULL);
     377        g_free (escaped);
     378      }
     379    
     380    icon = icon_iface->from_tokens (tokens + 1, num_tokens - 1, version, error);
     381  
     382   out:
     383    if (klass != NULL)
     384      g_type_class_unref (klass);
     385    return icon;
     386  }
     387  
     388  static void
     389  ensure_builtin_icon_types (void)
     390  {
     391    g_type_ensure (G_TYPE_THEMED_ICON);
     392    g_type_ensure (G_TYPE_FILE_ICON);
     393    g_type_ensure (G_TYPE_EMBLEMED_ICON);
     394    g_type_ensure (G_TYPE_EMBLEM);
     395  }
     396  
     397  /* handles the 'simple' cases: GFileIcon and GThemedIcon */
     398  static GIcon *
     399  g_icon_new_for_string_simple (const gchar *str)
     400  {
     401    gchar *scheme;
     402    GIcon *icon;
     403  
     404    if (str[0] == '.')
     405      return NULL;
     406  
     407    /* handle special GFileIcon and GThemedIcon cases */
     408    scheme = g_uri_parse_scheme (str);
     409    if (scheme != NULL || str[0] == '/' || str[0] == G_DIR_SEPARATOR)
     410      {
     411        GFile *location;
     412        location = g_file_new_for_commandline_arg (str);
     413        icon = g_file_icon_new (location);
     414        g_object_unref (location);
     415      }
     416    else
     417      icon = g_themed_icon_new (str);
     418  
     419    g_free (scheme);
     420  
     421    return icon;
     422  }
     423  
     424  /**
     425   * g_icon_new_for_string:
     426   * @str: A string obtained via g_icon_to_string().
     427   * @error: Return location for error.
     428   *
     429   * Generate a #GIcon instance from @str. This function can fail if
     430   * @str is not valid - see g_icon_to_string() for discussion.
     431   *
     432   * If your application or library provides one or more #GIcon
     433   * implementations you need to ensure that each #GType is registered
     434   * with the type system prior to calling g_icon_new_for_string().
     435   *
     436   * Returns: (transfer full): An object implementing the #GIcon
     437   *          interface or %NULL if @error is set.
     438   *
     439   * Since: 2.20
     440   **/
     441  GIcon *
     442  g_icon_new_for_string (const gchar   *str,
     443                         GError       **error)
     444  {
     445    GIcon *icon = NULL;
     446  
     447    g_return_val_if_fail (str != NULL, NULL);
     448  
     449    icon = g_icon_new_for_string_simple (str);
     450    if (icon)
     451      return icon;
     452  
     453    ensure_builtin_icon_types ();
     454  
     455    if (g_str_has_prefix (str, G_ICON_SERIALIZATION_MAGIC0))
     456      {
     457        gchar **tokens;
     458  
     459        /* handle tokenized encoding */
     460        tokens = g_strsplit (str + sizeof (G_ICON_SERIALIZATION_MAGIC0) - 1, " ", 0);
     461        icon = g_icon_new_from_tokens (tokens, error);
     462        g_strfreev (tokens);
     463      }
     464    else
     465      g_set_error_literal (error,
     466                           G_IO_ERROR,
     467                           G_IO_ERROR_INVALID_ARGUMENT,
     468                           _("Can’t handle the supplied version of the icon encoding"));
     469  
     470    return icon;
     471  }
     472  
     473  static GEmblem *
     474  g_icon_deserialize_emblem (GVariant *value)
     475  {
     476    GVariant *emblem_metadata;
     477    GVariant *emblem_data;
     478    const gchar *origin_nick;
     479    GIcon *emblem_icon;
     480    GEmblem *emblem;
     481  
     482    g_variant_get (value, "(v@a{sv})", &emblem_data, &emblem_metadata);
     483  
     484    emblem = NULL;
     485  
     486    emblem_icon = g_icon_deserialize (emblem_data);
     487    if (emblem_icon != NULL)
     488      {
     489        /* Check if we should create it with an origin. */
     490        if (g_variant_lookup (emblem_metadata, "origin", "&s", &origin_nick))
     491          {
     492            GEnumClass *origin_class;
     493            GEnumValue *origin_value;
     494  
     495            origin_class = g_type_class_ref (G_TYPE_EMBLEM_ORIGIN);
     496            origin_value = g_enum_get_value_by_nick (origin_class, origin_nick);
     497            if (origin_value)
     498              emblem = g_emblem_new_with_origin (emblem_icon, origin_value->value);
     499            g_type_class_unref (origin_class);
     500          }
     501  
     502        /* We didn't create it with an origin, so do it without. */
     503        if (emblem == NULL)
     504          emblem = g_emblem_new (emblem_icon);
     505  
     506        g_object_unref (emblem_icon);
     507      }
     508  
     509    g_variant_unref (emblem_metadata);
     510    g_variant_unref (emblem_data);
     511  
     512    return emblem;
     513  }
     514  
     515  static GIcon *
     516  g_icon_deserialize_emblemed (GVariant *value)
     517  {
     518    GVariantIter *emblems;
     519    GVariant *icon_data;
     520    GIcon *main_icon;
     521    GIcon *icon;
     522  
     523    g_variant_get (value, "(va(va{sv}))", &icon_data, &emblems);
     524    main_icon = g_icon_deserialize (icon_data);
     525  
     526    if (main_icon)
     527      {
     528        GVariant *emblem_data;
     529  
     530        icon = g_emblemed_icon_new (main_icon, NULL);
     531  
     532        while ((emblem_data = g_variant_iter_next_value (emblems)))
     533          {
     534            GEmblem *emblem;
     535  
     536            emblem = g_icon_deserialize_emblem (emblem_data);
     537  
     538            if (emblem)
     539              {
     540                g_emblemed_icon_add_emblem (G_EMBLEMED_ICON (icon), emblem);
     541                g_object_unref (emblem);
     542              }
     543  
     544            g_variant_unref (emblem_data);
     545          }
     546  
     547        g_object_unref (main_icon);
     548      }
     549    else
     550      icon = NULL;
     551  
     552    g_variant_iter_free (emblems);
     553    g_variant_unref (icon_data);
     554  
     555    return icon;
     556  }
     557  
     558  /**
     559   * g_icon_deserialize:
     560   * @value: (transfer none): a #GVariant created with g_icon_serialize()
     561   *
     562   * Deserializes a #GIcon previously serialized using g_icon_serialize().
     563   *
     564   * Returns: (nullable) (transfer full): a #GIcon, or %NULL when deserialization fails.
     565   *
     566   * Since: 2.38
     567   */
     568  GIcon *
     569  g_icon_deserialize (GVariant *value)
     570  {
     571    const gchar *tag;
     572    GVariant *val;
     573    GIcon *icon;
     574  
     575    g_return_val_if_fail (value != NULL, NULL);
     576    g_return_val_if_fail (g_variant_is_of_type (value, G_VARIANT_TYPE_STRING) ||
     577                          g_variant_is_of_type (value, G_VARIANT_TYPE ("(sv)")), NULL);
     578  
     579    /* Handle some special cases directly so that people can hard-code
     580     * stuff into GMenuModel xml files without resorting to using GVariant
     581     * text format to describe one of the explicitly-tagged possibilities
     582     * below.
     583     */
     584    if (g_variant_is_of_type (value, G_VARIANT_TYPE_STRING))
     585      return g_icon_new_for_string_simple (g_variant_get_string (value, NULL));
     586  
     587    /* Otherwise, use the tagged union format */
     588    g_variant_get (value, "(&sv)", &tag, &val);
     589  
     590    icon = NULL;
     591  
     592    if (g_str_equal (tag, "file") && g_variant_is_of_type (val, G_VARIANT_TYPE_STRING))
     593      {
     594        GFile *file;
     595  
     596        file = g_file_new_for_commandline_arg (g_variant_get_string (val, NULL));
     597        icon = g_file_icon_new (file);
     598        g_object_unref (file);
     599      }
     600    else if (g_str_equal (tag, "themed") && g_variant_is_of_type (val, G_VARIANT_TYPE_STRING_ARRAY))
     601      {
     602        const gchar **names;
     603        gsize size;
     604  
     605        names = g_variant_get_strv (val, &size);
     606        icon = g_themed_icon_new_from_names ((gchar **) names, size);
     607        g_free (names);
     608      }
     609    else if (g_str_equal (tag, "bytes") && g_variant_is_of_type (val, G_VARIANT_TYPE_BYTESTRING))
     610      {
     611        GBytes *bytes;
     612  
     613        bytes = g_variant_get_data_as_bytes (val);
     614        icon = g_bytes_icon_new (bytes);
     615        g_bytes_unref (bytes);
     616      }
     617    else if (g_str_equal (tag, "emblem") && g_variant_is_of_type (val, G_VARIANT_TYPE ("(va{sv})")))
     618      {
     619        GEmblem *emblem;
     620  
     621        emblem = g_icon_deserialize_emblem (val);
     622        if (emblem)
     623          icon = G_ICON (emblem);
     624      }
     625    else if (g_str_equal (tag, "emblemed") && g_variant_is_of_type (val, G_VARIANT_TYPE ("(va(va{sv}))")))
     626      {
     627        icon = g_icon_deserialize_emblemed (val);
     628      }
     629    else if (g_str_equal (tag, "gvfs"))
     630      {
     631        GVfsClass *class;
     632        GVfs *vfs;
     633  
     634        vfs = g_vfs_get_default ();
     635        class = G_VFS_GET_CLASS (vfs);
     636        if (class->deserialize_icon)
     637          icon = (* class->deserialize_icon) (vfs, val);
     638      }
     639  
     640    g_variant_unref (val);
     641  
     642    return icon;
     643  }
     644  
     645  /**
     646   * g_icon_serialize: (virtual serialize)
     647   * @icon: a #GIcon
     648   *
     649   * Serializes a #GIcon into a #GVariant. An equivalent #GIcon can be retrieved
     650   * back by calling g_icon_deserialize() on the returned value.
     651   * As serialization will avoid using raw icon data when possible, it only
     652   * makes sense to transfer the #GVariant between processes on the same machine,
     653   * (as opposed to over the network), and within the same file system namespace.
     654   *
     655   * Returns: (nullable) (transfer full): a #GVariant, or %NULL when serialization fails. The #GVariant will not be floating.
     656   *
     657   * Since: 2.38
     658   */
     659  GVariant *
     660  g_icon_serialize (GIcon *icon)
     661  {
     662    GIconInterface *iface;
     663    GVariant *result;
     664  
     665    iface = G_ICON_GET_IFACE (icon);
     666  
     667    if (!iface->serialize)
     668      {
     669        g_critical ("g_icon_serialize() on icon type '%s' is not implemented", G_OBJECT_TYPE_NAME (icon));
     670        return NULL;
     671      }
     672  
     673    result = (* iface->serialize) (icon);
     674  
     675    if (result)
     676      {
     677        g_variant_take_ref (result);
     678  
     679        if (!g_variant_is_of_type (result, G_VARIANT_TYPE ("(sv)")))
     680          {
     681            g_critical ("g_icon_serialize() on icon type '%s' returned GVariant of type '%s' but it must return "
     682                        "one with type '(sv)'", G_OBJECT_TYPE_NAME (icon), g_variant_get_type_string (result));
     683            g_variant_unref (result);
     684            result = NULL;
     685          }
     686      }
     687  
     688    return result;
     689  }