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, write to the
17 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
18 * Boston, MA 02111-1307, USA.
19 *
20 * Author: Alexander Larsson <alexl@redhat.com>
21 */
22
23#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
24#error "Only <gio/gio.h> can be included directly."
25#endif
26
27#ifndef __G_SEEKABLE_H__
28#define __G_SEEKABLE_H__
29
30#include <gio/giotypes.h>
31
32G_BEGIN_DECLS
33
34#define G_TYPE_SEEKABLE            (g_seekable_get_type ())
35#define G_SEEKABLE(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_SEEKABLE, GSeekable))
36#define G_IS_SEEKABLE(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_SEEKABLE))
37#define G_SEEKABLE_GET_IFACE(obj)  (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_SEEKABLE, GSeekableIface))
38
39/**
40 * GSeekable:
41 *
42 * Seek object for streaming operations.
43 **/
44typedef struct _GSeekableIface   GSeekableIface;
45
46/**
47 * GSeekableIface:
48 * @g_iface: The parent interface.
49 * @tell: Tells the current location within a stream.
50 * @can_seek: Checks if seeking is supported by the stream.
51 * @seek: Seeks to a location within a stream.
52 * @can_truncate: Chekcs if truncation is suppored by the stream.
53 * @truncate_fn: Truncates a stream.
54 *
55 * Provides an interface for implementing seekable functionality on I/O Streams.
56 **/
57struct _GSeekableIface
58{
59  GTypeInterface g_iface;
60
61  /* Virtual Table */
62
63  goffset     (* tell)	         (GSeekable    *seekable);
64
65  gboolean    (* can_seek)       (GSeekable    *seekable);
66  gboolean    (* seek)	         (GSeekable    *seekable,
67				  goffset       offset,
68				  GSeekType     type,
69				  GCancellable *cancellable,
70				  GError      **error);
71
72  gboolean    (* can_truncate)   (GSeekable    *seekable);
73  gboolean    (* truncate_fn)    (GSeekable    *seekable,
74				  goffset       offset,
75				  GCancellable *cancellable,
76				  GError       **error);
77
78  /* TODO: Async seek/truncate */
79};
80
81GType    g_seekable_get_type     (void) G_GNUC_CONST;
82
83goffset  g_seekable_tell         (GSeekable     *seekable);
84gboolean g_seekable_can_seek     (GSeekable     *seekable);
85gboolean g_seekable_seek         (GSeekable     *seekable,
86				  goffset        offset,
87				  GSeekType      type,
88				  GCancellable  *cancellable,
89				  GError       **error);
90gboolean g_seekable_can_truncate (GSeekable     *seekable);
91gboolean g_seekable_truncate     (GSeekable     *seekable,
92				  goffset        offset,
93				  GCancellable  *cancellable,
94				  GError       **error);
95
96G_END_DECLS
97
98
99#endif /* __G_SEEKABLE_H__ */
100