gio/gloadableicon.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 "gicon.h"
  25 #include "gloadableicon.h"
  26 #include "gasyncresult.h"
  27 #include "gtask.h"
  28 #include "glibintl.h"
  29
  30
  31 /**
  32  * SECTION:gloadableicon
  33  * @short_description: Loadable Icons
  34  * @include: gio/gio.h
  35  * @see_also: #GIcon, #GThemedIcon
  36  *
  37  * Extends the #GIcon interface and adds the ability to
  38  * load icons from streams.
  39  **/
  40
  41 static void          g_loadable_icon_real_load_async  (GLoadableIcon        *icon,
  42                                                        int                   size,
  43                                                        GCancellable         *cancellable,
  44                                                        GAsyncReadyCallback   callback,
  45                                                        gpointer              user_data);
  46 static GInputStream *g_loadable_icon_real_load_finish (GLoadableIcon        *icon,
  47                                                        GAsyncResult         *res,
  48                                                        char                **type,
  49                                                        GError              **error);
  50
  51 typedef GLoadableIconIface GLoadableIconInterface;
  52 G_DEFINE_INTERFACE(GLoadableIcon, g_loadable_icon, G_TYPE_ICON)
  53
  54 static void
  55 g_loadable_icon_default_init (GLoadableIconIface *iface)
  56 {
  57   iface->load_async = g_loadable_icon_real_load_async;
  58   iface->load_finish = g_loadable_icon_real_load_finish;
  59 }
  60
  61 /**
  62  * g_loadable_icon_load:
  63  * @icon: a #GLoadableIcon.
  64  * @size: an integer.
  65  * @type: (out) (optional): a location to store the type of the loaded
  66  * icon, %NULL to ignore.
  67  * @cancellable: (nullable): optional #GCancellable object, %NULL to
  68  * ignore.
  69  * @error: a #GError location to store the error occurring, or %NULL
  70  * to ignore.
  71  *
  72  * Loads a loadable icon. For the asynchronous version of this function,
  73  * see g_loadable_icon_load_async().
  74  *
  75  * Returns: (transfer full): a #GInputStream to read the icon from.
  76  **/
  77 GInputStream *
  78 g_loadable_icon_load (GLoadableIcon  *icon,
  79                       int             size,
  80                       char          **type,
  81                       GCancellable   *cancellable,
  82                       GError        **error)
  83 {
  84   GLoadableIconIface *iface;
  85
  86   g_return_val_if_fail (G_IS_LOADABLE_ICON (icon), NULL);
  87
  88   iface = G_LOADABLE_ICON_GET_IFACE (icon);
  89
  90   return (* iface->load) (icon, size, type, cancellable, error);
  91 }
  92
  93 /**
  94  * g_loadable_icon_load_async:
  95  * @icon: a #GLoadableIcon.
  96  * @size: an integer.
  97  * @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
  98  * @callback: (scope async): a #GAsyncReadyCallback
  99  *   to call when the request is satisfied
 100  * @user_data: the data to pass to callback function
 101  *
 102  * Loads an icon asynchronously. To finish this function, see
 103  * g_loadable_icon_load_finish(). For the synchronous, blocking
 104  * version of this function, see g_loadable_icon_load().
 105  **/
 106 void
 107 g_loadable_icon_load_async (GLoadableIcon       *icon,
 108                             int                  size,
 109                             GCancellable        *cancellable,
 110                             GAsyncReadyCallback  callback,
 111                             gpointer             user_data)
 112 {
 113   GLoadableIconIface *iface;
 114
 115   g_return_if_fail (G_IS_LOADABLE_ICON (icon));
 116
 117   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 118
 119   (* iface->load_async) (icon, size, cancellable, callback, user_data);
 120 }
 121
 122 /**
 123  * g_loadable_icon_load_finish:
 124  * @icon: a #GLoadableIcon.
 125  * @res: a #GAsyncResult.
 126  * @type: (out) (optional): a location to store the type of the loaded
 127  *        icon, %NULL to ignore.
 128  * @error: a #GError location to store the error occurring, or %NULL to
 129  * ignore.
 130  *
 131  * Finishes an asynchronous icon load started in g_loadable_icon_load_async().
 132  *
 133  * Returns: (transfer full): a #GInputStream to read the icon from.
 134  **/
 135 GInputStream *
 136 g_loadable_icon_load_finish (GLoadableIcon  *icon,
 137                              GAsyncResult   *res,
 138                              char          **type,
 139                              GError        **error)
 140 {
 141   GLoadableIconIface *iface;
 142
 143   g_return_val_if_fail (G_IS_LOADABLE_ICON (icon), NULL);
 144   g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL);
 145
 146   if (g_async_result_legacy_propagate_error (res, error))
 147     return NULL;
 148
 149   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 150
 151   return (* iface->load_finish) (icon, res, type, error);
 152 }
 153
 154 /********************************************
 155  *   Default implementation of async load   *
 156  ********************************************/
 157
 158 typedef struct {
 159   int size;
 160   char *type;
 161 } LoadData;
 162
 163 static void
 164 load_data_free (LoadData *data)
 165 {
 166   g_free (data->type);
 167   g_free (data);
 168 }
 169
 170 static void
 171 load_async_thread (GTask        *task,
 172                    gpointer      source_object,
 173                    gpointer      task_data,
 174                    GCancellable *cancellable)
 175 {
 176   GLoadableIcon *icon = source_object;
 177   LoadData *data = task_data;
 178   GLoadableIconIface *iface;
 179   GInputStream *stream;
 180   GError *error = NULL;
 181
 182   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 183   stream = iface->load (icon, data->size, &data->type,
 184                         cancellable, &error);
 185
 186   if (stream)
 187     g_task_return_pointer (task, stream, g_object_unref);
 188   else
 189     g_task_return_error (task, error);
 190 }
 191
 192
 193
 194 static void
 195 g_loadable_icon_real_load_async (GLoadableIcon       *icon,
 196                                  int                  size,
 197                                  GCancellable        *cancellable,
 198                                  GAsyncReadyCallback  callback,
 199                                  gpointer             user_data)
 200 {
 201   GTask *task;
 202   LoadData *data;
 203
 204   task = g_task_new (icon, cancellable, callback, user_data);
 205   g_task_set_source_tag (task, g_loadable_icon_real_load_async);
 206   data = g_new0 (LoadData, 1);
 207   g_task_set_task_data (task, data, (GDestroyNotify) load_data_free);
 208   g_task_run_in_thread (task, load_async_thread);
 209   g_object_unref (task);
 210 }
 211
 212 static GInputStream *
 213 g_loadable_icon_real_load_finish (GLoadableIcon        *icon,
 214                                   GAsyncResult         *res,
 215                                   char                **type,
 216                                   GError              **error)
 217 {
 218   GTask *task;
 219   LoadData *data;
 220   GInputStream *stream;
 221
 222   g_return_val_if_fail (g_task_is_valid (res, icon), NULL);
 223
 224   task = G_TASK (res);
 225   data = g_task_get_task_data (task);
 226
 227   stream = g_task_propagate_pointer (task, error);
 228   if (stream && type)
 229     {
 230       *type = data->type;
 231       data->type = NULL;
 232     }
 233
 234   return stream;
 235 }