2 * Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
4 * gstbus.h: Header for GstBus subsystem
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
25 typedef struct _GstBus GstBus;
26 typedef struct _GstBusPrivate GstBusPrivate;
27 typedef struct _GstBusClass GstBusClass;
29 #include <gst/gstmessage.h>
30 #include <gst/gstclock.h>
31 #include <gst/gstatomicqueue.h>
35 /* --- standard type macros --- */
36 #define GST_TYPE_BUS (gst_bus_get_type ())
37 #define GST_BUS(bus) (G_TYPE_CHECK_INSTANCE_CAST ((bus), GST_TYPE_BUS, GstBus))
38 #define GST_IS_BUS(bus) (G_TYPE_CHECK_INSTANCE_TYPE ((bus), GST_TYPE_BUS))
39 #define GST_BUS_CLASS(bclass) (G_TYPE_CHECK_CLASS_CAST ((bclass), GST_TYPE_BUS, GstBusClass))
40 #define GST_IS_BUS_CLASS(bclass) (G_TYPE_CHECK_CLASS_TYPE ((bclass), GST_TYPE_BUS))
41 #define GST_BUS_GET_CLASS(bus) (G_TYPE_INSTANCE_GET_CLASS ((bus), GST_TYPE_BUS, GstBusClass))
42 #define GST_BUS_CAST(bus) ((GstBus*)(bus))
46 * @GST_BUS_FLUSHING: The bus is currently dropping all messages
47 * @GST_BUS_FLAG_LAST: offset to define more flags
49 * The standard flags that a bus may have.
52 GST_BUS_FLUSHING = (GST_OBJECT_FLAG_LAST << 0),
54 GST_BUS_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 1)
59 * @GST_BUS_DROP: drop the message
60 * @GST_BUS_PASS: pass the message to the async queue
61 * @GST_BUS_ASYNC: pass message to async queue, continue if message is handled
63 * The result values for a GstBusSyncHandler.
74 * @bus: the #GstBus that sent the message
75 * @message: the #GstMessage
76 * @data: user data that has been given, when registering the handler
78 * Handler will be invoked synchronously, when a new message has been injected
79 * into the bus. This function is mostly used internally. Only one sync handler
80 * can be attached to a given bus.
82 * If the handler returns GST_BUS_DROP, it should unref the message, else the
83 * message should not be unreffed by the sync handler.
85 * Returns: #GstBusSyncReply stating what to do with the message
87 typedef GstBusSyncReply (*GstBusSyncHandler) (GstBus * bus, GstMessage * message, gpointer data);
91 * @bus: the #GstBus that sent the message
92 * @message: the #GstMessage
93 * @data: user data that has been given, when registering the handler
95 * Specifies the type of function passed to gst_bus_add_watch() or
96 * gst_bus_add_watch_full(), which is called from the mainloop when a message
97 * is available on the bus.
99 * The message passed to the function will be unreffed after execution of this
100 * function so it should not be freed in the function.
102 * Note that this function is used as a GSourceFunc which means that returning
103 * FALSE will remove the GSource from the mainloop.
105 * Returns: %FALSE if the event source should be removed.
107 typedef gboolean (*GstBusFunc) (GstBus * bus, GstMessage * message, gpointer data);
112 * The opaque #GstBus data structure.
121 gpointer _gst_reserved[GST_PADDING];
126 GstObjectClass parent_class;
129 void (*message) (GstBus *bus, GstMessage *message);
130 void (*sync_message) (GstBus *bus, GstMessage *message);
133 gpointer _gst_reserved[GST_PADDING];
136 GType gst_bus_get_type (void);
138 GstBus* gst_bus_new (void);
140 gboolean gst_bus_post (GstBus * bus, GstMessage * message);
142 gboolean gst_bus_have_pending (GstBus * bus);
143 GstMessage * gst_bus_peek (GstBus * bus);
144 GstMessage * gst_bus_pop (GstBus * bus);
145 GstMessage * gst_bus_pop_filtered (GstBus * bus, GstMessageType types);
146 GstMessage * gst_bus_timed_pop (GstBus * bus, GstClockTime timeout);
147 GstMessage * gst_bus_timed_pop_filtered (GstBus * bus, GstClockTime timeout, GstMessageType types);
148 void gst_bus_set_flushing (GstBus * bus, gboolean flushing);
150 /* synchronous dispatching */
151 void gst_bus_set_sync_handler (GstBus * bus, GstBusSyncHandler func,
153 /* GSource based dispatching */
154 GSource * gst_bus_create_watch (GstBus * bus);
155 guint gst_bus_add_watch_full (GstBus * bus,
159 GDestroyNotify notify);
160 guint gst_bus_add_watch (GstBus * bus,
164 /* polling the bus */
165 GstMessage* gst_bus_poll (GstBus *bus, GstMessageType events,
166 GstClockTimeDiff timeout);
168 /* signal based dispatching helper functions. */
169 gboolean gst_bus_async_signal_func (GstBus *bus, GstMessage *message,
171 GstBusSyncReply gst_bus_sync_signal_handler (GstBus *bus, GstMessage *message,
174 /* convenience api to add/remove a gsource that emits the async signals */
175 void gst_bus_add_signal_watch (GstBus * bus);
176 void gst_bus_add_signal_watch_full (GstBus * bus, gint priority);
177 void gst_bus_remove_signal_watch (GstBus * bus);
179 void gst_bus_enable_sync_message_emission (GstBus * bus);
180 void gst_bus_disable_sync_message_emission (GstBus * bus);
184 #endif /* __GST_BUS_H__ */