gstreamer/gst/gstbin.h
Wim Taymans 5209b1b0a2 Make message handling overridable.
Original commit message from CVS:
* docs/design/part-TODO.txt:
* gst/gstbin.c: (gst_bin_class_init), (gst_bin_provide_clock_func),
(gst_bin_add_func), (gst_bin_remove_func), (bin_bus_handler),
(gst_bin_handle_message_func):
* gst/gstbin.h:
Make message handling overridable.
2005-11-19 18:28:40 +00:00

177 lines
5.6 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbin.h: Header for GstBin container object
*
* 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_BIN_H__
#define __GST_BIN_H__
#include <gst/gstelement.h>
#include <gst/gstiterator.h>
#include <gst/gstbus.h>
G_BEGIN_DECLS
#define GST_TYPE_BIN (gst_bin_get_type ())
#define GST_IS_BIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BIN))
#define GST_IS_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BIN))
#define GST_BIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BIN, GstBinClass))
#define GST_BIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BIN, GstBin))
#define GST_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BIN, GstBinClass))
#define GST_BIN_CAST(obj) ((GstBin*)(obj))
/**
* GstBinFlags:
* @GST_BIN_FLAG_LAST: the last enum in the series of flags for bins.
* Derived classes can use this as first value in a list of flags.
*
* GstBinFlags are a set of flags specific to bins. Most are set/used
* internally. They can be checked using the GST_OBJECT_FLAG_IS_SET () macro,
* and (un)set using GST_OBJECT_FLAG_SET () and GST_OBJECT_FLAG_UNSET ().
*/
typedef enum {
/* padding */
GST_BIN_FLAG_LAST = (GST_ELEMENT_FLAG_LAST << 5)
} GstBinFlags;
typedef struct _GstBin GstBin;
typedef struct _GstBinClass GstBinClass;
/**
* GST_BIN_NUMCHILDREN:
* @bin: a #GstBin
*
* Gets the number of children in a bin.
*/
#define GST_BIN_NUMCHILDREN(bin) (GST_BIN_CAST(bin)->numchildren)
/**
* GST_BIN_CHILDREN:
* @bin: a #GstBin
*
* Gets the list with children in a bin.
*/
#define GST_BIN_CHILDREN(bin) (GST_BIN_CAST(bin)->children)
/**
* GST_BIN_CHILDREN_COOKIE:
* @bin: a #GstBin
*
* Gets the children cookie that watches the children list.
*/
#define GST_BIN_CHILDREN_COOKIE(bin) (GST_BIN_CAST(bin)->children_cookie)
/**
* GstBin:
* @numchildren: the number of children in this bin
* @children: the list of children in this bin
* @children_cookie: updated whenever @children changes
* @child_bus: internal bus for handling child messages
* @messages: queued messages
* @polling: the bin is currently calculating its state
* @state_dirty: the bin needs to recalculate its state
* @clock_dirty: the bin needs to select a new clock
* @provided_clock: the last clock selected
* @clock_provider: the element that provided @provided_clock
*
* The GstBin base class. Subclasses can access these fields provided
* the LOCK is taken.
*/
struct _GstBin {
GstElement element;
/*< public >*/ /* with LOCK */
/* our children, subclass are supposed to update these
* fields to reflect their state with _iterate_*() */
gint numchildren;
GList *children;
guint32 children_cookie;
GstBus *child_bus;
GList *messages;
gboolean polling;
gboolean state_dirty;
gboolean clock_dirty;
GstClock *provided_clock;
GstElement *clock_provider;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
/**
* GstBinClass:
* @parent_class: bin parent class
* @add_element: method to add an element to a bin
* @remove_element: method to remove an element from a bin
* @handle_message: method to handle a message from the children
*
* Subclasses can override the @add_element and @remove_element to
* update the list of children in the bin.
*
* The @handle_message method can be overriden to implement custom
* message handling.
*/
struct _GstBinClass {
GstElementClass parent_class;
/*< private >*/
GThreadPool *pool;
/* signals */
void (*element_added) (GstBin *bin, GstElement *child);
void (*element_removed) (GstBin *bin, GstElement *child);
/*< public >*/
/* virtual methods for subclasses */
gboolean (*add_element) (GstBin *bin, GstElement *element);
gboolean (*remove_element) (GstBin *bin, GstElement *element);
void (*handle_message) (GstBin *bin, GstMessage *message);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_bin_get_type (void);
GstElement* gst_bin_new (const gchar *name);
/* add and remove elements from the bin */
gboolean gst_bin_add (GstBin *bin, GstElement *element);
gboolean gst_bin_remove (GstBin *bin, GstElement *element);
/* retrieve a single child */
GstElement* gst_bin_get_by_name (GstBin *bin, const gchar *name);
GstElement* gst_bin_get_by_name_recurse_up (GstBin *bin, const gchar *name);
GstElement* gst_bin_get_by_interface (GstBin *bin, GType interface);
/* retrieve multiple children */
GstIterator* gst_bin_iterate_elements (GstBin *bin);
GstIterator* gst_bin_iterate_sorted (GstBin *bin);
GstIterator* gst_bin_iterate_recurse (GstBin *bin);
GstIterator* gst_bin_iterate_sinks (GstBin *bin);
GstIterator* gst_bin_iterate_all_by_interface (GstBin *bin, GType interface);
G_END_DECLS
#endif /* __GST_BIN_H__ */