mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-23 18:21:04 +00:00
87 lines
3 KiB
C
87 lines
3 KiB
C
/* GStreamer
|
|
* Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
|
|
*
|
|
* 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_EXAMPLE_H__
|
|
#define __GST_EXAMPLE_H__
|
|
|
|
#include <gst/gst.h>
|
|
|
|
G_BEGIN_DECLS
|
|
|
|
/* This is the definition of the element's object structure. */
|
|
typedef struct _GstExample GstExample;
|
|
|
|
/* The structure itself is derived from GstElement, as can be seen by the
|
|
* fact that there's a complete instance of the GstElement structure at
|
|
* the beginning of the object. This allows the element to be cast to
|
|
* an Element or even an Object.
|
|
*/
|
|
struct _GstExample {
|
|
GstElement element;
|
|
|
|
/* We need to keep track of our pads, so we do so here. */
|
|
GstPad *sinkpad,*srcpad;
|
|
|
|
/* We'll use this to decide whether to do anything to the data we get. */
|
|
gboolean active;
|
|
};
|
|
|
|
/* The other half of the object is its class. The class also derives from
|
|
* the same parent, though it must be the class structure this time.
|
|
* Function pointers for polymophic methods and signals are placed in this
|
|
* structure. */
|
|
typedef struct _GstExampleClass GstExampleClass;
|
|
|
|
struct _GstExampleClass {
|
|
GstElementClass parent_class;
|
|
|
|
/* signals */
|
|
void (*asdf) (GstElement *element, GstExample *example);
|
|
};
|
|
|
|
/* Five standard preprocessing macros are used in the Gtk+ object system.
|
|
* The first uses the object's _get_type function to return the GType
|
|
* of the object.
|
|
*/
|
|
#define GST_TYPE_EXAMPLE \
|
|
(gst_example_get_type())
|
|
/* The second is a checking cast to the correct type. If the object passed
|
|
* is not the right type, a warning will be generated on stderr.
|
|
*/
|
|
#define GST_EXAMPLE(obj) \
|
|
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_EXAMPLE,GstExample))
|
|
/* The third is a checking cast of the class instead of the object. */
|
|
#define GST_EXAMPLE_CLASS(klass) \
|
|
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_EXAMPLE,GstExampleClass))
|
|
/* The last two simply check to see if the passed pointer is an object or
|
|
* class of the correct type. */
|
|
#define GST_IS_EXAMPLE(obj) \
|
|
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_EXAMPLE))
|
|
#define GST_IS_EXAMPLE_CLASS(obj) \
|
|
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_EXAMPLE))
|
|
|
|
/* This is the only prototype needed, because it is used in the above
|
|
* GST_TYPE_EXAMPLE macro.
|
|
*/
|
|
GType gst_example_get_type(void);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __GST_EXAMPLE_H__ */
|