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/* GStreamer
* Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
*
* gstbus.h: Header for GstBus subsystem
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_BUS_H__
#define __GST_BUS_H__
typedef struct _GstBus GstBus;
typedef struct _GstBusPrivate GstBusPrivate;
typedef struct _GstBusClass GstBusClass;
#include <gst/gstmessage.h>
#include <gst/gstclock.h>
G_BEGIN_DECLS
/* --- standard type macros --- */
#define GST_TYPE_BUS (gst_bus_get_type ())
#define GST_BUS(bus) (G_TYPE_CHECK_INSTANCE_CAST ((bus), GST_TYPE_BUS, GstBus))
#define GST_IS_BUS(bus) (G_TYPE_CHECK_INSTANCE_TYPE ((bus), GST_TYPE_BUS))
#define GST_BUS_CLASS(bclass) (G_TYPE_CHECK_CLASS_CAST ((bclass), GST_TYPE_BUS, GstBusClass))
#define GST_IS_BUS_CLASS(bclass) (G_TYPE_CHECK_CLASS_TYPE ((bclass), GST_TYPE_BUS))
#define GST_BUS_GET_CLASS(bus) (G_TYPE_INSTANCE_GET_CLASS ((bus), GST_TYPE_BUS, GstBusClass))
#define GST_BUS_CAST(bus) ((GstBus*)(bus))
/**
* GstBusFlags:
* @GST_BUS_FLUSHING: The bus is currently dropping all messages
* @GST_BUS_FLAG_LAST: offset to define more flags
*
* The standard flags that a bus may have.
*/
typedef enum {
GST_BUS_FLUSHING = (GST_OBJECT_FLAG_LAST << 0),
/* padding */
GST_BUS_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 1)
} GstBusFlags;
/**
* GstBusSyncReply:
* @GST_BUS_DROP: drop the message
* @GST_BUS_PASS: pass the message to the async queue
* @GST_BUS_ASYNC: pass message to async queue, continue if message is handled
*
* The result values for a GstBusSyncHandler.
*/
typedef enum
{
GST_BUS_DROP = 0,
GST_BUS_PASS = 1,
GST_BUS_ASYNC = 2
} GstBusSyncReply;
/**
* GstBusSyncHandler:
* @bus: the #GstBus that sent the message
* @message: the #GstMessage
* @user_data: user data that has been given, when registering the handler
*
* Handler will be invoked synchronously, when a new message has been injected
* into the bus. This function is mostly used internally. Only one sync handler
* can be attached to a given bus.
*
* If the handler returns GST_BUS_DROP, it should unref the message, else the
* message should not be unreffed by the sync handler.
*
* Returns: #GstBusSyncReply stating what to do with the message
*/
typedef GstBusSyncReply (*GstBusSyncHandler) (GstBus * bus, GstMessage * message, gpointer user_data);
/**
* GstBusFunc:
* @bus: the #GstBus that sent the message
* @message: the #GstMessage
* @user_data: user data that has been given, when registering the handler
*
* Specifies the type of function passed to gst_bus_add_watch() or
* gst_bus_add_watch_full(), which is called from the mainloop when a message
* is available on the bus.
*
* The message passed to the function will be unreffed after execution of this
* function so it should not be freed in the function.
*
* Note that this function is used as a GSourceFunc which means that returning
* FALSE will remove the GSource from the mainloop.
*
* Returns: %FALSE if the event source should be removed.
*/
typedef gboolean (*GstBusFunc) (GstBus * bus, GstMessage * message, gpointer user_data);
/**
* GstBus:
*
* The opaque #GstBus data structure.
*/
struct _GstBus
{
GstObject object;
/*< private >*/
GstBusPrivate *priv;
gpointer _gst_reserved[GST_PADDING];
};
struct _GstBusClass
{
GstObjectClass parent_class;
/* signals */
void (*message) (GstBus *bus, GstMessage *message);
void (*sync_message) (GstBus *bus, GstMessage *message);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_bus_get_type (void);
GstBus* gst_bus_new (void);
gboolean gst_bus_post (GstBus * bus, GstMessage * message);
gboolean gst_bus_have_pending (GstBus * bus);
GstMessage * gst_bus_peek (GstBus * bus);
GstMessage * gst_bus_pop (GstBus * bus);
GstMessage * gst_bus_pop_filtered (GstBus * bus, GstMessageType types);
GstMessage * gst_bus_timed_pop (GstBus * bus, GstClockTime timeout);
GstMessage * gst_bus_timed_pop_filtered (GstBus * bus, GstClockTime timeout, GstMessageType types);
void gst_bus_set_flushing (GstBus * bus, gboolean flushing);
/* synchronous dispatching */
void gst_bus_set_sync_handler (GstBus * bus, GstBusSyncHandler func,
gpointer user_data, GDestroyNotify notify);
/* GSource based dispatching */
GSource * gst_bus_create_watch (GstBus * bus);
guint gst_bus_add_watch_full (GstBus * bus,
gint priority,
GstBusFunc func,
gpointer user_data,
GDestroyNotify notify);
guint gst_bus_add_watch (GstBus * bus,
GstBusFunc func,
gpointer user_data);
/* polling the bus */
GstMessage* gst_bus_poll (GstBus *bus, GstMessageType events,
GstClockTime timeout);
/* signal based dispatching helper functions. */
gboolean gst_bus_async_signal_func (GstBus *bus, GstMessage *message,
gpointer data);
GstBusSyncReply gst_bus_sync_signal_handler (GstBus *bus, GstMessage *message,
gpointer data);
/* convenience api to add/remove a gsource that emits the async signals */
void gst_bus_add_signal_watch (GstBus * bus);
void gst_bus_add_signal_watch_full (GstBus * bus, gint priority);
void gst_bus_remove_signal_watch (GstBus * bus);
void gst_bus_enable_sync_message_emission (GstBus * bus);
void gst_bus_disable_sync_message_emission (GstBus * bus);
G_END_DECLS
#endif /* __GST_BUS_H__ */
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