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 30 G_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 **/ 42 typedef 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 **/ 55 struct _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 79 GLIB_AVAILABLE_IN_ALL 80 GType g_seekable_get_type (void) G_GNUC_CONST; 81 82 GLIB_AVAILABLE_IN_ALL 83 goffset g_seekable_tell (GSeekable *seekable); 84 GLIB_AVAILABLE_IN_ALL 85 gboolean g_seekable_can_seek (GSeekable *seekable); 86 GLIB_AVAILABLE_IN_ALL 87 gboolean g_seekable_seek (GSeekable *seekable, 88 goffset offset, 89 GSeekType type, 90 GCancellable *cancellable, 91 GError **error); 92 GLIB_AVAILABLE_IN_ALL 93 gboolean g_seekable_can_truncate (GSeekable *seekable); 94 GLIB_AVAILABLE_IN_ALL 95 gboolean g_seekable_truncate (GSeekable *seekable, 96 goffset offset, 97 GCancellable *cancellable, 98 GError **error); 99 100 G_END_DECLS 101 102 103 #endif /* __G_SEEKABLE_H__ */ 104