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 32 G_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 **/ 44 typedef 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 **/ 57 struct _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 81 GType g_seekable_get_type (void) G_GNUC_CONST; 82 83 goffset g_seekable_tell (GSeekable *seekable); 84 gboolean g_seekable_can_seek (GSeekable *seekable); 85 gboolean g_seekable_seek (GSeekable *seekable, 86 goffset offset, 87 GSeekType type, 88 GCancellable *cancellable, 89 GError **error); 90 gboolean g_seekable_can_truncate (GSeekable *seekable); 91 gboolean g_seekable_truncate (GSeekable *seekable, 92 goffset offset, 93 GCancellable *cancellable, 94 GError **error); 95 96 G_END_DECLS 97 98 99 #endif /* __G_SEEKABLE_H__ */ 100