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 2.1 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#ifndef __G_SEEKABLE_H__
22#define __G_SEEKABLE_H__
23
24#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
25#error "Only <gio/gio.h> can be included directly."
26#endif
27
28#include <gio/giotypes.h>
29
30G_BEGIN_DECLS
31
32#define G_TYPE_SEEKABLE (g_seekable_get_type ())
33#define G_SEEKABLE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_SEEKABLE, GSeekable))
34#define G_IS_SEEKABLE(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_SEEKABLE))
35#define G_SEEKABLE_GET_IFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_SEEKABLE, GSeekableIface))
36
37/**
38 * GSeekable:
39 *
40 * Seek object for streaming operations.
41 **/
42typedef struct _GSeekableIface GSeekableIface;
43
44/**
45 * GSeekableIface:
46 * @g_iface: The parent interface.
47 * @tell: Tells the current location within a stream.
48 * @can_seek: Checks if seeking is supported by the stream.
49 * @seek: Seeks to a location within a stream.
50 * @can_truncate: Checks if truncation is supported by the stream.
51 * @truncate_fn: Truncates a stream.
52 *
53 * Provides an interface for implementing seekable functionality on I/O Streams.
54 **/
55struct _GSeekableIface
56{
57 GTypeInterface g_iface;
58
59 /* Virtual Table */
60
61 goffset (* tell) (GSeekable *seekable);
62
63 gboolean (* can_seek) (GSeekable *seekable);
64 gboolean (* seek) (GSeekable *seekable,
65 goffset offset,
66 GSeekType type,
67 GCancellable *cancellable,
68 GError **error);
69
70 gboolean (* can_truncate) (GSeekable *seekable);
71 gboolean (* truncate_fn) (GSeekable *seekable,
72 goffset offset,
73 GCancellable *cancellable,
74 GError **error);
75
76 /* TODO: Async seek/truncate */
77};
78
79GLIB_AVAILABLE_IN_ALL
80GType g_seekable_get_type (void) G_GNUC_CONST;
81
82GLIB_AVAILABLE_IN_ALL
83goffset g_seekable_tell (GSeekable *seekable);
84GLIB_AVAILABLE_IN_ALL
85gboolean g_seekable_can_seek (GSeekable *seekable);
86GLIB_AVAILABLE_IN_ALL
87gboolean g_seekable_seek (GSeekable *seekable,
88 goffset offset,
89 GSeekType type,
90 GCancellable *cancellable,
91 GError **error);
92GLIB_AVAILABLE_IN_ALL
93gboolean g_seekable_can_truncate (GSeekable *seekable);
94GLIB_AVAILABLE_IN_ALL
95gboolean g_seekable_truncate (GSeekable *seekable,
96 goffset offset,
97 GCancellable *cancellable,
98 GError **error);
99
100G_END_DECLS
101
102
103#endif /* __G_SEEKABLE_H__ */
104

source code of gtk/subprojects/glib/gio/gseekable.h