/* GStreamer * Copyright (C) 2004 Wim Taymans * * 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., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #ifndef __GST_BUS_H__ #define __GST_BUS_H__ typedef struct _GstBus GstBus; typedef struct _GstBusPrivate GstBusPrivate; typedef struct _GstBusClass GstBusClass; #include #include #include 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 * @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 data); /** * GstBusFunc: * @bus: the #GstBus that sent the message * @message: the #GstMessage * @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 data); /** * GstBus: * * The opaque #GstBus data structure. */ struct _GstBus { GstObject object; /*< private >*/ GstAtomicQueue *queue; GMutex *queue_lock; GstBusSyncHandler sync_handler; gpointer sync_handler_data; guint signal_watch_id; guint num_signal_watchers; /*< private >*/ GstBusPrivate *priv; gpointer _gst_reserved[GST_PADDING - 1]; }; 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 data); /* 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, GstClockTimeDiff 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__ */