| /* GIO - GLib Input, Output and Streaming Library |
| * |
| * Copyright (C) 2006-2007 Red Hat, Inc. |
| * |
| * 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 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, write to the |
| * Free Software Foundation, Inc., 59 Temple Place, Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * |
| * Author: Alexander Larsson <alexl@redhat.com> |
| */ |
| |
| #include "config.h" |
| #include "gasyncresult.h" |
| #include "glibintl.h" |
| |
| |
| /** |
| * SECTION:gasyncresult |
| * @short_description: Asynchronous Function Results |
| * @include: gio/gio.h |
| * @see_also: #GSimpleAsyncResult |
| * |
| * Provides a base class for implementing asynchronous function results. |
| * |
| * Asynchronous operations are broken up into two separate operations |
| * which are chained together by a #GAsyncReadyCallback. To begin |
| * an asynchronous operation, provide a #GAsyncReadyCallback to the |
| * asynchronous function. This callback will be triggered when the |
| * operation has completed, and will be passed a #GAsyncResult instance |
| * filled with the details of the operation's success or failure, the |
| * object the asynchronous function was started for and any error codes |
| * returned. The asynchronous callback function is then expected to call |
| * the corresponding "_finish()" function, passing the object the |
| * function was called for, the #GAsyncResult instance, and (optionally) |
| * an @error to grab any error conditions that may have occurred. |
| * |
| * The "_finish()" function for an operation takes the generic result |
| * (of type #GAsyncResult) and returns the specific result that the |
| * operation in question yields (e.g. a #GFileEnumerator for a |
| * "enumerate children" operation). If the result or error status of the |
| * operation is not needed, there is no need to call the "_finish()" |
| * function; GIO will take care of cleaning up the result and error |
| * information after the #GAsyncReadyCallback returns. You can pass |
| * %NULL for the #GAsyncReadyCallback if you don't need to take any |
| * action at all after the operation completes. Applications may also |
| * take a reference to the #GAsyncResult and call "_finish()" later; |
| * however, the "_finish()" function may be called at most once. |
| * |
| * Example of a typical asynchronous operation flow: |
| * |[ |
| * void _theoretical_frobnitz_async (Theoretical *t, |
| * GCancellable *c, |
| * GAsyncReadyCallback *cb, |
| * gpointer u); |
| * |
| * gboolean _theoretical_frobnitz_finish (Theoretical *t, |
| * GAsyncResult *res, |
| * GError **e); |
| * |
| * static void |
| * frobnitz_result_func (GObject *source_object, |
| * GAsyncResult *res, |
| * gpointer user_data) |
| * { |
| * gboolean success = FALSE; |
| * |
| * success = _theoretical_frobnitz_finish (source_object, res, NULL); |
| * |
| * if (success) |
| * g_printf ("Hurray!\n"); |
| * else |
| * g_printf ("Uh oh!\n"); |
| * |
| * /<!-- -->* ... *<!-- -->/ |
| * |
| * } |
| * |
| * int main (int argc, void *argv[]) |
| * { |
| * /<!-- -->* ... *<!-- -->/ |
| * |
| * _theoretical_frobnitz_async (theoretical_data, |
| * NULL, |
| * frobnitz_result_func, |
| * NULL); |
| * |
| * /<!-- -->* ... *<!-- -->/ |
| * } |
| * ]| |
| * |
| * The callback for an asynchronous operation is called only once, and is |
| * always called, even in the case of a cancelled operation. On cancellation |
| * the result is a %G_IO_ERROR_CANCELLED error. |
| **/ |
| |
| typedef GAsyncResultIface GAsyncResultInterface; |
| G_DEFINE_INTERFACE (GAsyncResult, g_async_result, G_TYPE_OBJECT) |
| |
| static void |
| g_async_result_default_init (GAsyncResultInterface *iface) |
| { |
| } |
| |
| /** |
| * g_async_result_get_user_data: |
| * @res: a #GAsyncResult. |
| * |
| * Gets the user data from a #GAsyncResult. |
| * |
| * Returns: (transfer full): the user data for @res. |
| **/ |
| gpointer |
| g_async_result_get_user_data (GAsyncResult *res) |
| { |
| GAsyncResultIface *iface; |
| |
| g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL); |
| |
| iface = G_ASYNC_RESULT_GET_IFACE (res); |
| |
| return (* iface->get_user_data) (res); |
| } |
| |
| /** |
| * g_async_result_get_source_object: |
| * @res: a #GAsyncResult |
| * |
| * Gets the source object from a #GAsyncResult. |
| * |
| * Returns: (transfer full): a new reference to the source object for the @res, |
| * or %NULL if there is none. |
| */ |
| GObject * |
| g_async_result_get_source_object (GAsyncResult *res) |
| { |
| GAsyncResultIface *iface; |
| |
| g_return_val_if_fail (G_IS_ASYNC_RESULT (res), NULL); |
| |
| iface = G_ASYNC_RESULT_GET_IFACE (res); |
| |
| return (* iface->get_source_object) (res); |
| } |