gio/gloadableicon.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, see <http://www.gnu.org/licenses/>.
  17  *
  18  * Author: Alexander Larsson <alexl@redhat.com>
  19  */
  20
  21 #include "config.h"
  22 #include "gicon.h"
  23 #include "gloadableicon.h"
  24 #include "gasyncresult.h"
  25 #include "gtask.h"
  26 #include "glibintl.h"
  27
  28
  29 /**
  30  * SECTION:gloadableicon
  31  * @short_description: Loadable Icons
  32  * @include: gio/gio.h
  33  * @see_also: #GIcon, #GThemedIcon
  34  *
  35  * Extends the #GIcon interface and adds the ability to
  36  * load icons from streams.
  37  **/
  38
  39 static void          g_loadable_icon_real_load_async  (GLoadableIcon        *icon,
  40                                                        int                   size,
  41                                                        GCancellable         *cancellable,
  42                                                        GAsyncReadyCallback   callback,
  43                                                        gpointer              user_data);
  44 static GInputStream *g_loadable_icon_real_load_finish (GLoadableIcon        *icon,
  45                                                        GAsyncResult         *res,
  46                                                        char                **type,
  47                                                        GError              **error);
  48
  49 typedef GLoadableIconIface GLoadableIconInterface;
  50 G_DEFINE_INTERFACE(GLoadableIcon, g_loadable_icon, G_TYPE_ICON)
  51
  52 static void
  53 g_loadable_icon_default_init (GLoadableIconIface *iface)
  54 {
  55   iface->load_async = g_loadable_icon_real_load_async;
  56   iface->load_finish = g_loadable_icon_real_load_finish;
  57 }
  58
  59 /**
  60  * g_loadable_icon_load:
  61  * @icon: a #GLoadableIcon.
  62  * @size: an integer.
  63  * @type: (out) (optional): a location to store the type of the loaded
  64  * icon, %NULL to ignore.
  65  * @cancellable: (allow-none): optional #GCancellable object, %NULL to
  66  * ignore.
  67  * @error: a #GError location to store the error occurring, or %NULL
  68  * to ignore.
  69  *
  70  * Loads a loadable icon. For the asynchronous version of this function,
  71  * see g_loadable_icon_load_async().
  72  *
  73  * Returns: (transfer full): a #GInputStream to read the icon from.
  74  **/
  75 GInputStream *
  76 g_loadable_icon_load (GLoadableIcon  *icon,
  77                       int             size,
  78                       char          **type,
  79                       GCancellable   *cancellable,
  80                       GError        **error)
  81 {
  82   GLoadableIconIface *iface;
  83
  84   g_return_val_if_fail (G_IS_LOADABLE_ICON (icon), NULL);
  85
  86   iface = G_LOADABLE_ICON_GET_IFACE (icon);
  87
  88   return (* iface->load) (icon, size, type, cancellable, error);
  89 }
  90
  91 /**
  92  * g_loadable_icon_load_async:
  93  * @icon: a #GLoadableIcon.
  94  * @size: an integer.
  95  * @cancellable: (allow-none): optional #GCancellable object, %NULL to ignore.
  96  * @callback: (scope async): a #GAsyncReadyCallback to call when the
  97  *            request is satisfied
  98  * @user_data: (closure): the data to pass to callback function
  99  *
 100  * Loads an icon asynchronously. To finish this function, see
 101  * g_loadable_icon_load_finish(). For the synchronous, blocking
 102  * version of this function, see g_loadable_icon_load().
 103  **/
 104 void
 105 g_loadable_icon_load_async (GLoadableIcon       *icon,
 106                             int                  size,
 107                             GCancellable        *cancellable,
 108                             GAsyncReadyCallback  callback,
 109                             gpointer             user_data)
 110 {
 111   GLoadableIconIface *iface;
 112
 113   g_return_if_fail (G_IS_LOADABLE_ICON (icon));
 114
 115   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 116
 117   (* iface->load_async) (icon, size, cancellable, callback, user_data);
 118 }
 119
 120 /**
 121  * g_loadable_icon_load_finish:
 122  * @icon: a #GLoadableIcon.
 123  * @res: a #GAsyncResult.
 124  * @type: (out) (optional): a location to store the type of the loaded
 125  *        icon, %NULL to ignore.
 126  * @error: a #GError location to store the error occurring, or %NULL to
 127  * ignore.
 128  *
 129  * Finishes an asynchronous icon load started in g_loadable_icon_load_async().
 130  *
 131  * Returns: (transfer full): a #GInputStream to read the icon from.
 132  **/
 133 GInputStream *
 134 g_loadable_icon_load_finish (GLoadableIcon  *icon,
 135                              GAsyncResult   *res,
 136                              char          **type,
 137                              GError        **error)
 138 {
 139   GLoadableIconIface *iface;
 140
 141   g_return_val_if_fail (G_IS_LOADABLE_ICON (icon), NULL);
 142   g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL);
 143
 144   if (g_async_result_legacy_propagate_error (res, error))
 145     return NULL;
 146
 147   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 148
 149   return (* iface->load_finish) (icon, res, type, error);
 150 }
 151
 152 /********************************************
 153  *   Default implementation of async load   *
 154  ********************************************/
 155
 156 typedef struct {
 157   int size;
 158   char *type;
 159 } LoadData;
 160
 161 static void
 162 load_data_free (LoadData *data)
 163 {
 164   g_free (data->type);
 165   g_free (data);
 166 }
 167
 168 static void
 169 load_async_thread (GTask        *task,
 170                    gpointer      source_object,
 171                    gpointer      task_data,
 172                    GCancellable *cancellable)
 173 {
 174   GLoadableIcon *icon = source_object;
 175   LoadData *data = task_data;
 176   GLoadableIconIface *iface;
 177   GInputStream *stream;
 178   GError *error = NULL;
 179
 180   iface = G_LOADABLE_ICON_GET_IFACE (icon);
 181   stream = iface->load (icon, data->size, &data->type,
 182                         cancellable, &error);
 183
 184   if (stream)
 185     g_task_return_pointer (task, stream, g_object_unref);
 186   else
 187     g_task_return_error (task, error);
 188 }
 189
 190
 191
 192 static void
 193 g_loadable_icon_real_load_async (GLoadableIcon       *icon,
 194                                  int                  size,
 195                                  GCancellable        *cancellable,
 196                                  GAsyncReadyCallback  callback,
 197                                  gpointer             user_data)
 198 {
 199   GTask *task;
 200   LoadData *data;
 201
 202   task = g_task_new (icon, cancellable, callback, user_data);
 203   data = g_new0 (LoadData, 1);
 204   g_task_set_task_data (task, data, (GDestroyNotify) load_data_free);
 205   g_task_run_in_thread (task, load_async_thread);
 206   g_object_unref (task);
 207 }
 208
 209 static GInputStream *
 210 g_loadable_icon_real_load_finish (GLoadableIcon        *icon,
 211                                   GAsyncResult         *res,
 212                                   char                **type,
 213                                   GError              **error)
 214 {
 215   GTask *task;
 216   LoadData *data;
 217   GInputStream *stream;
 218
 219   g_return_val_if_fail (g_task_is_valid (res, icon), NULL);
 220
 221   task = G_TASK (res);
 222   data = g_task_get_task_data (task);
 223
 224   stream = g_task_propagate_pointer (task, error);
 225   if (stream && type)
 226     {
 227       *type = data->type;
 228       data->type = NULL;
 229     }
 230
 231   return stream;
 232 }