glib/gio/gicon.c
Philip Withnall 824ae3f931 docs: Move the GIcon SECTION
Move it to the struct docs.

Signed-off-by: Philip Withnall <philip@tecnocode.co.uk>

Helps: #3037
2023-10-23 13:18:13 +01:00

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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include "gicon.h"
#include "gthemedicon.h"
#include "gfileicon.h"
#include "gemblemedicon.h"
#include "gbytesicon.h"
#include "gfile.h"
#include "gioerror.h"
#include "gioenumtypes.h"
#include "gvfs.h"
#include "glibintl.h"
/* There versioning of this is implicit, version 1 would be ".1 " */
#define G_ICON_SERIALIZATION_MAGIC0 ". "
/**
* GIcon:
*
* `GIcon` is a very minimal interface for icons. It provides functions
* for checking the equality of two icons, hashing of icons and
* serializing an icon to and from strings.
*
* `GIcon` does not provide the actual pixmap for the icon as this is out
* of GIO's scope, however implementations of `GIcon` may contain the name
* of an icon (see [class@Gio.ThemedIcon]), or the path to an icon
* (see [iface@Gio.LoadableIcon]).
*
* To obtain a hash of a `GIcon`, see [method@Gio.Icon.hash].
*
* To check if two `GIcon`s are equal, see [method@Gio.Icon.equal].
*
* For serializing a `GIcon`, use [method@Gio.Icon.serialize] and
* [func@Gio.Icon.deserialize].
*
* If you want to consume `GIcon` (for example, in a toolkit) you must
* be prepared to handle at least the three following cases:
* [iface@Gio.LoadableIcon], [class@Gio.ThemedIcon] and [class@Gio.EmblemedIcon].
* It may also make sense to have fast-paths for other cases (like handling
* [class@GdkPixbuf.Pixbuf] directly, for example) but all compliant `GIcon`
* implementations outside of GIO must implement [iface@Gio.LoadableIcon].
*
* If your application or library provides one or more `GIcon`
* implementations you need to ensure that your new implementation also
* implements [iface@Gio.LoadableIcon]. Additionally, you must provide an
* implementation of [method@Gio.Icon.serialize] that gives a result that is
* understood by [func@Gio.Icon.deserialize], yielding one of the built-in
* icon types.
**/
typedef GIconIface GIconInterface;
G_DEFINE_INTERFACE(GIcon, g_icon, G_TYPE_OBJECT)
static void
g_icon_default_init (GIconInterface *iface)
{
}
/**
* g_icon_hash: (hash)
* @icon: (not nullable) (type Gio.Icon): #gconstpointer to an icon object.
*
* Gets a hash for an icon.
*
* Returns: a #guint containing a hash for the @icon, suitable for
* use in a #GHashTable or similar data structure.
**/
guint
g_icon_hash (gconstpointer icon)
{
GIconIface *iface;
g_return_val_if_fail (G_IS_ICON (icon), 0);
iface = G_ICON_GET_IFACE (icon);
return (* iface->hash) ((GIcon *)icon);
}
/**
* g_icon_equal: (virtual equal)
* @icon1: (nullable): pointer to the first #GIcon.
* @icon2: (nullable): pointer to the second #GIcon.
*
* Checks if two icons are equal.
*
* Returns: %TRUE if @icon1 is equal to @icon2. %FALSE otherwise.
**/
gboolean
g_icon_equal (GIcon *icon1,
GIcon *icon2)
{
GIconIface *iface;
if (icon1 == NULL && icon2 == NULL)
return TRUE;
if (icon1 == NULL || icon2 == NULL)
return FALSE;
if (G_TYPE_FROM_INSTANCE (icon1) != G_TYPE_FROM_INSTANCE (icon2))
return FALSE;
iface = G_ICON_GET_IFACE (icon1);
return (* iface->equal) (icon1, icon2);
}
static gboolean
g_icon_to_string_tokenized (GIcon *icon, GString *s)
{
GPtrArray *tokens;
gint version;
GIconIface *icon_iface;
guint i;
g_return_val_if_fail (icon != NULL, FALSE);
g_return_val_if_fail (G_IS_ICON (icon), FALSE);
icon_iface = G_ICON_GET_IFACE (icon);
if (icon_iface->to_tokens == NULL)
return FALSE;
tokens = g_ptr_array_new ();
if (!icon_iface->to_tokens (icon, tokens, &version))
{
g_ptr_array_free (tokens, TRUE);
return FALSE;
}
/* format: TypeName[.Version] <token_0> .. <token_N-1>
version 0 is implicit and can be omitted
all the tokens are url escaped to ensure they have no spaces in them */
g_string_append (s, g_type_name_from_instance ((GTypeInstance *)icon));
if (version != 0)
g_string_append_printf (s, ".%d", version);
for (i = 0; i < tokens->len; i++)
{
char *token;
token = g_ptr_array_index (tokens, i);
g_string_append_c (s, ' ');
/* We really only need to escape spaces here, so allow lots of otherwise reserved chars */
g_string_append_uri_escaped (s, token,
G_URI_RESERVED_CHARS_ALLOWED_IN_PATH, TRUE);
g_free (token);
}
g_ptr_array_free (tokens, TRUE);
return TRUE;
}
/**
* g_icon_to_string:
* @icon: a #GIcon.
*
* Generates a textual representation of @icon that can be used for
* serialization such as when passing @icon to a different process or
* saving it to persistent storage. Use g_icon_new_for_string() to
* get @icon back from the returned string.
*
* The encoding of the returned string is proprietary to #GIcon except
* in the following two cases
*
* - If @icon is a #GFileIcon, the returned string is a native path
* (such as `/path/to/my icon.png`) without escaping
* if the #GFile for @icon is a native file. If the file is not
* native, the returned string is the result of g_file_get_uri()
* (such as `sftp://path/to/my%20icon.png`).
*
* - If @icon is a #GThemedIcon with exactly one name and no fallbacks,
* the encoding is simply the name (such as `network-server`).
*
* Returns: (nullable): An allocated NUL-terminated UTF8 string or
* %NULL if @icon can't be serialized. Use g_free() to free.
*
* Since: 2.20
*/
gchar *
g_icon_to_string (GIcon *icon)
{
gchar *ret;
g_return_val_if_fail (icon != NULL, NULL);
g_return_val_if_fail (G_IS_ICON (icon), NULL);
ret = NULL;
if (G_IS_FILE_ICON (icon))
{
GFile *file;
file = g_file_icon_get_file (G_FILE_ICON (icon));
if (g_file_is_native (file))
{
ret = g_file_get_path (file);
if (!g_utf8_validate (ret, -1, NULL))
{
g_free (ret);
ret = NULL;
}
}
else
ret = g_file_get_uri (file);
}
else if (G_IS_THEMED_ICON (icon))
{
char **names = NULL;
gboolean use_default_fallbacks = FALSE;
g_object_get (G_OBJECT (icon),
"names", &names,
"use-default-fallbacks", &use_default_fallbacks,
NULL);
/* Themed icon initialized with a single name and no fallbacks. */
if (names != NULL &&
names[0] != NULL &&
names[0][0] != '.' && /* Allowing icons starting with dot would break G_ICON_SERIALIZATION_MAGIC0 */
g_utf8_validate (names[0], -1, NULL) && /* Only return utf8 strings */
names[1] == NULL &&
! use_default_fallbacks)
ret = g_strdup (names[0]);
g_strfreev (names);
}
if (ret == NULL)
{
GString *s;
s = g_string_new (G_ICON_SERIALIZATION_MAGIC0);
if (g_icon_to_string_tokenized (icon, s))
ret = g_string_free (s, FALSE);
else
g_string_free (s, TRUE);
}
return ret;
}
static GIcon *
g_icon_new_from_tokens (char **tokens,
GError **error)
{
GIcon *icon;
char *typename, *version_str;
GType type;
gpointer klass;
GIconIface *icon_iface;
gint version;
char *endp;
int num_tokens;
int i;
icon = NULL;
klass = NULL;
num_tokens = g_strv_length (tokens);
if (num_tokens < 1)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Wrong number of tokens (%d)"),
num_tokens);
goto out;
}
typename = tokens[0];
version_str = strchr (typename, '.');
if (version_str)
{
*version_str = 0;
version_str += 1;
}
type = g_type_from_name (tokens[0]);
if (type == 0)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("No type for class name %s"),
tokens[0]);
goto out;
}
if (!g_type_is_a (type, G_TYPE_ICON))
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Type %s does not implement the GIcon interface"),
tokens[0]);
goto out;
}
klass = g_type_class_ref (type);
if (klass == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Type %s is not classed"),
tokens[0]);
goto out;
}
version = 0;
if (version_str)
{
version = strtol (version_str, &endp, 10);
if (endp == NULL || *endp != '\0')
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Malformed version number: %s"),
version_str);
goto out;
}
}
icon_iface = g_type_interface_peek (klass, G_TYPE_ICON);
g_assert (icon_iface != NULL);
if (icon_iface->from_tokens == NULL)
{
g_set_error (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Type %s does not implement from_tokens() on the GIcon interface"),
tokens[0]);
goto out;
}
for (i = 1; i < num_tokens; i++)
{
char *escaped;
escaped = tokens[i];
tokens[i] = g_uri_unescape_string (escaped, NULL);
g_free (escaped);
}
icon = icon_iface->from_tokens (tokens + 1, num_tokens - 1, version, error);
out:
if (klass != NULL)
g_type_class_unref (klass);
return icon;
}
static void
ensure_builtin_icon_types (void)
{
g_type_ensure (G_TYPE_THEMED_ICON);
g_type_ensure (G_TYPE_FILE_ICON);
g_type_ensure (G_TYPE_EMBLEMED_ICON);
g_type_ensure (G_TYPE_EMBLEM);
}
/* handles the 'simple' cases: GFileIcon and GThemedIcon */
static GIcon *
g_icon_new_for_string_simple (const gchar *str)
{
gchar *scheme;
GIcon *icon;
if (str[0] == '.')
return NULL;
/* handle special GFileIcon and GThemedIcon cases */
scheme = g_uri_parse_scheme (str);
if (scheme != NULL || str[0] == '/' || str[0] == G_DIR_SEPARATOR)
{
GFile *location;
location = g_file_new_for_commandline_arg (str);
icon = g_file_icon_new (location);
g_object_unref (location);
}
else
icon = g_themed_icon_new (str);
g_free (scheme);
return icon;
}
/**
* g_icon_new_for_string:
* @str: A string obtained via g_icon_to_string().
* @error: Return location for error.
*
* Generate a #GIcon instance from @str. This function can fail if
* @str is not valid - see g_icon_to_string() for discussion.
*
* If your application or library provides one or more #GIcon
* implementations you need to ensure that each #GType is registered
* with the type system prior to calling g_icon_new_for_string().
*
* Returns: (transfer full): An object implementing the #GIcon
* interface or %NULL if @error is set.
*
* Since: 2.20
**/
GIcon *
g_icon_new_for_string (const gchar *str,
GError **error)
{
GIcon *icon = NULL;
g_return_val_if_fail (str != NULL, NULL);
icon = g_icon_new_for_string_simple (str);
if (icon)
return icon;
ensure_builtin_icon_types ();
if (g_str_has_prefix (str, G_ICON_SERIALIZATION_MAGIC0))
{
gchar **tokens;
/* handle tokenized encoding */
tokens = g_strsplit (str + sizeof (G_ICON_SERIALIZATION_MAGIC0) - 1, " ", 0);
icon = g_icon_new_from_tokens (tokens, error);
g_strfreev (tokens);
}
else
g_set_error_literal (error,
G_IO_ERROR,
G_IO_ERROR_INVALID_ARGUMENT,
_("Cant handle the supplied version of the icon encoding"));
return icon;
}
static GEmblem *
g_icon_deserialize_emblem (GVariant *value)
{
GVariant *emblem_metadata;
GVariant *emblem_data;
const gchar *origin_nick;
GIcon *emblem_icon;
GEmblem *emblem;
g_variant_get (value, "(v@a{sv})", &emblem_data, &emblem_metadata);
emblem = NULL;
emblem_icon = g_icon_deserialize (emblem_data);
if (emblem_icon != NULL)
{
/* Check if we should create it with an origin. */
if (g_variant_lookup (emblem_metadata, "origin", "&s", &origin_nick))
{
GEnumClass *origin_class;
GEnumValue *origin_value;
origin_class = g_type_class_ref (G_TYPE_EMBLEM_ORIGIN);
origin_value = g_enum_get_value_by_nick (origin_class, origin_nick);
if (origin_value)
emblem = g_emblem_new_with_origin (emblem_icon, origin_value->value);
g_type_class_unref (origin_class);
}
/* We didn't create it with an origin, so do it without. */
if (emblem == NULL)
emblem = g_emblem_new (emblem_icon);
g_object_unref (emblem_icon);
}
g_variant_unref (emblem_metadata);
g_variant_unref (emblem_data);
return emblem;
}
static GIcon *
g_icon_deserialize_emblemed (GVariant *value)
{
GVariantIter *emblems;
GVariant *icon_data;
GIcon *main_icon;
GIcon *icon;
g_variant_get (value, "(va(va{sv}))", &icon_data, &emblems);
main_icon = g_icon_deserialize (icon_data);
if (main_icon)
{
GVariant *emblem_data;
icon = g_emblemed_icon_new (main_icon, NULL);
while ((emblem_data = g_variant_iter_next_value (emblems)))
{
GEmblem *emblem;
emblem = g_icon_deserialize_emblem (emblem_data);
if (emblem)
{
g_emblemed_icon_add_emblem (G_EMBLEMED_ICON (icon), emblem);
g_object_unref (emblem);
}
g_variant_unref (emblem_data);
}
g_object_unref (main_icon);
}
else
icon = NULL;
g_variant_iter_free (emblems);
g_variant_unref (icon_data);
return icon;
}
/**
* g_icon_deserialize:
* @value: (transfer none): a #GVariant created with g_icon_serialize()
*
* Deserializes a #GIcon previously serialized using g_icon_serialize().
*
* Returns: (nullable) (transfer full): a #GIcon, or %NULL when deserialization fails.
*
* Since: 2.38
*/
GIcon *
g_icon_deserialize (GVariant *value)
{
const gchar *tag;
GVariant *val;
GIcon *icon;
g_return_val_if_fail (value != NULL, NULL);
g_return_val_if_fail (g_variant_is_of_type (value, G_VARIANT_TYPE_STRING) ||
g_variant_is_of_type (value, G_VARIANT_TYPE ("(sv)")), NULL);
/* Handle some special cases directly so that people can hard-code
* stuff into GMenuModel xml files without resorting to using GVariant
* text format to describe one of the explicitly-tagged possibilities
* below.
*/
if (g_variant_is_of_type (value, G_VARIANT_TYPE_STRING))
return g_icon_new_for_string_simple (g_variant_get_string (value, NULL));
/* Otherwise, use the tagged union format */
g_variant_get (value, "(&sv)", &tag, &val);
icon = NULL;
if (g_str_equal (tag, "file") && g_variant_is_of_type (val, G_VARIANT_TYPE_STRING))
{
GFile *file;
file = g_file_new_for_commandline_arg (g_variant_get_string (val, NULL));
icon = g_file_icon_new (file);
g_object_unref (file);
}
else if (g_str_equal (tag, "themed") && g_variant_is_of_type (val, G_VARIANT_TYPE_STRING_ARRAY))
{
const gchar **names;
gsize size;
names = g_variant_get_strv (val, &size);
icon = g_themed_icon_new_from_names ((gchar **) names, size);
g_free (names);
}
else if (g_str_equal (tag, "bytes") && g_variant_is_of_type (val, G_VARIANT_TYPE_BYTESTRING))
{
GBytes *bytes;
bytes = g_variant_get_data_as_bytes (val);
icon = g_bytes_icon_new (bytes);
g_bytes_unref (bytes);
}
else if (g_str_equal (tag, "emblem") && g_variant_is_of_type (val, G_VARIANT_TYPE ("(va{sv})")))
{
GEmblem *emblem;
emblem = g_icon_deserialize_emblem (val);
if (emblem)
icon = G_ICON (emblem);
}
else if (g_str_equal (tag, "emblemed") && g_variant_is_of_type (val, G_VARIANT_TYPE ("(va(va{sv}))")))
{
icon = g_icon_deserialize_emblemed (val);
}
else if (g_str_equal (tag, "gvfs"))
{
GVfsClass *class;
GVfs *vfs;
vfs = g_vfs_get_default ();
class = G_VFS_GET_CLASS (vfs);
if (class->deserialize_icon)
icon = (* class->deserialize_icon) (vfs, val);
}
g_variant_unref (val);
return icon;
}
/**
* g_icon_serialize: (virtual serialize)
* @icon: a #GIcon
*
* Serializes a #GIcon into a #GVariant. An equivalent #GIcon can be retrieved
* back by calling g_icon_deserialize() on the returned value.
* As serialization will avoid using raw icon data when possible, it only
* makes sense to transfer the #GVariant between processes on the same machine,
* (as opposed to over the network), and within the same file system namespace.
*
* Returns: (nullable) (transfer full): a #GVariant, or %NULL when serialization fails. The #GVariant will not be floating.
*
* Since: 2.38
*/
GVariant *
g_icon_serialize (GIcon *icon)
{
GIconInterface *iface;
GVariant *result;
iface = G_ICON_GET_IFACE (icon);
if (!iface->serialize)
{
g_critical ("g_icon_serialize() on icon type '%s' is not implemented", G_OBJECT_TYPE_NAME (icon));
return NULL;
}
result = (* iface->serialize) (icon);
if (result)
{
g_variant_take_ref (result);
if (!g_variant_is_of_type (result, G_VARIANT_TYPE ("(sv)")))
{
g_critical ("g_icon_serialize() on icon type '%s' returned GVariant of type '%s' but it must return "
"one with type '(sv)'", G_OBJECT_TYPE_NAME (icon), g_variant_get_type_string (result));
g_variant_unref (result);
result = NULL;
}
}
return result;
}