glib/gio/gseekable.h

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/* 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>
*/
#if !defined (__GIO_GIO_H_INSIDE__) && !defined (GIO_COMPILATION)
#error "Only <gio/gio.h> can be included directly."
#endif
#ifndef __G_SEEKABLE_H__
#define __G_SEEKABLE_H__
#include <gio/giotypes.h>
G_BEGIN_DECLS
#define G_TYPE_SEEKABLE (g_seekable_get_type ())
#define G_SEEKABLE(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_SEEKABLE, GSeekable))
#define G_IS_SEEKABLE(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_SEEKABLE))
#define G_SEEKABLE_GET_IFACE(obj) (G_TYPE_INSTANCE_GET_INTERFACE ((obj), G_TYPE_SEEKABLE, GSeekableIface))
/**
* GSeekable:
*
* Seek object for streaming operations.
**/
typedef struct _GSeekableIface GSeekableIface;
/**
* GSeekableIface:
* @g_iface: The parent interface.
* @tell: Tells the current location within a stream.
* @can_seek: Checks if seeking is supported by the stream.
* @seek: Seeks to a location within a stream.
* @can_truncate: Checks if truncation is supported by the stream.
* @truncate_fn: Truncates a stream.
*
* Provides an interface for implementing seekable functionality on I/O Streams.
**/
struct _GSeekableIface
{
GTypeInterface g_iface;
/* Virtual Table */
goffset (* tell) (GSeekable *seekable);
gboolean (* can_seek) (GSeekable *seekable);
gboolean (* seek) (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error);
gboolean (* can_truncate) (GSeekable *seekable);
gboolean (* truncate_fn) (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error);
/* TODO: Async seek/truncate */
};
GType g_seekable_get_type (void) G_GNUC_CONST;
goffset g_seekable_tell (GSeekable *seekable);
gboolean g_seekable_can_seek (GSeekable *seekable);
gboolean g_seekable_seek (GSeekable *seekable,
goffset offset,
GSeekType type,
GCancellable *cancellable,
GError **error);
gboolean g_seekable_can_truncate (GSeekable *seekable);
gboolean g_seekable_truncate (GSeekable *seekable,
goffset offset,
GCancellable *cancellable,
GError **error);
G_END_DECLS
#endif /* __G_SEEKABLE_H__ */