gst/gstelement.h

/* Gnome-Streamer
 * 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_ELEMENT_H__
#define __GST_ELEMENT_H__


#include <gnome-xml/parser.h>
#include <gst/gstlog.h>
#include <gst/gstobject.h>
#include <gst/gstpad.h>
#include <gst/gstbuffer.h>
#include <gst/cothreads.h>


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */


typedef enum {
  GST_STATE_COMPLETE    = (1 << 0),
  GST_STATE_RUNNING     = (1 << 1),
  GST_STATE_DISCOVERY   = (1 << 2),
  GST_STATE_PREROLL     = (1 << 3),

  GST_STATE_PLAYING	= (1 << 4),
  GST_STATE_PAUSED	= (1 << 5),

  GST_STATE_MAX		= (1 << 15),
} GstElementState;


#define GST_STATE(obj)			(GST_ELEMENT(obj)->state)
#define GST_STATE_IS_SET(obj,flag)	(GST_STATE (obj) & (flag))
#define GST_STATE_SET(obj,flag) \
G_STMT_START{ (GST_STATE (obj) |= (flag)); \
gst_info("set '%s' state %d\n",gst_element_get_name(obj),flag); \
}G_STMT_END
#define GST_STATE_UNSET(obj,flag) \
G_STMT_START{ (GST_STATE (obj) &= ~(flag)); \
gst_info("unset '%s' state %d\n",gst_element_get_name(obj),flag); \
}G_STMT_END


#define GST_TYPE_ELEMENT \
  (gst_element_get_type())
#define GST_ELEMENT(obj) \
  (GTK_CHECK_CAST((obj),GST_TYPE_ELEMENT,GstElement))
#define GST_ELEMENT_CLASS(klass) \
  (GTK_CHECK_CLASS_CAST((klass),GST_TYPE_ELEMENT,GstElementClass))
#define GST_IS_ELEMENT(obj) \
  (GTK_CHECK_TYPE((obj),GST_TYPE_ELEMENT))
#define GST_IS_ELEMENT_CLASS(obj) \
  (GTK_CHECK_CLASS_TYPE((klass),GST_TYPE_ELEMENT)))

typedef struct _GstElement GstElement;
typedef struct _GstElementClass GstElementClass;
typedef struct _GstElementDetails GstElementDetails;
typedef struct _GstElementFactory GstElementFactory;

typedef void (*GstElementLoopFunction) (GstElement *element);

struct _GstElement {
  GstObject object;

  gchar *name;

  guint16 state;

  GstElementLoopFunction loopfunc;
  cothread_state *threadstate;

  guint16 numpads;
  GList *pads;

  GstElement *manager;
};

struct _GstElementClass {
  GstObjectClass parent_class;

  /* the elementfactory that created us */
  GstElementFactory *elementfactory;

  /* signal callbacks */
  void (*state_change) (GstElement *element,GstElementState state);
  void (*new_pad) (GstElement *element,GstPad *pad);
  void (*new_ghost_pad) (GstElement *element,GstPad *pad);
  void (*error) (GstElement *element,gchar *error);

  /* events */
  gboolean (*start) (GstElement *element,GstElementState state);
  gboolean (*stop) (GstElement *element);

  /* change the element state */
  gboolean (*change_state) (GstElement *element,GstElementState state);

  /* create or read XML representation of self */
  xmlNodePtr (*save_thyself)(GstElement *element,xmlNodePtr parent);
  void (*restore_thyself)(GstElement *element,xmlNodePtr *self);
};

struct _GstElementDetails {
  gchar *longname;              /* long, english name */
  gchar *class;                 /* type of element, kinda */
  gchar *description;           /* insights of one form or another */
  gchar *version;               /* version of the element */
  gchar *author;                /* who wrote this thing? */
  gchar *copyright;             /* copyright details (year, etc.) */
};

struct _GstElementFactory {
  gchar *name;
  GtkType type;

  GstElementDetails *details;
};


GtkType gst_element_get_type(void);
GstElement *gst_element_new(void);

void gst_element_set_loop_function(GstElement *element,
                                   GstElementLoopFunction loop);

void gst_element_set_name(GstElement *element,gchar *name);
gchar *gst_element_get_name(GstElement *element);

void gst_element_set_manager(GstElement *element,GstElement *manager);
GstElement *gst_element_get_manager(GstElement *element);

void gst_element_add_pad(GstElement *element,GstPad *pad);
void gst_element_add_ghost_pad(GstElement *element,GstPad *pad);
GstPad *gst_element_get_pad(GstElement *element,gchar *name);
GList *gst_element_get_pad_list(GstElement *element);

void gst_element_connect(GstElement *src,gchar *srcpadname,
                         GstElement *dest,gchar *destpadname);

/* called by the app to set the state of the element */
gboolean gst_element_set_state(GstElement *element,GstElementState state);

void gst_element_error(GstElement *element,gchar *error);

/* callback to actually set the state */
gboolean gst_element_change_state(GstElement *element,
                                  GstElementState state);

#define gst_element_destroy(element) gst_object_destroy(GST_OBJECT(element))

/* XML write and read */
xmlNodePtr gst_element_save_thyself(GstElement *element,xmlNodePtr parent);


GstElementFactory *gst_elementfactory_new(gchar *name,GtkType type,
                                          GstElementDetails *details);
void gst_elementfactory_register(GstElementFactory *elementfactory);

GstElementFactory *gst_elementfactory_find(gchar *name);
GList *gst_elementfactory_get_list();

GstElement *gst_elementfactory_create(GstElementFactory *factory,
                                      gchar *name);
  
// FIXME this name is wrong, probably so is the one above it
GstElement *gst_elementfactory_make(gchar *factoryname,gchar *name);

int gst_element_loopfunc_wrapper(int argc,char **argv);

#ifdef __cplusplus
}
#endif /* __cplusplus */


#endif /* __GST_ELEMENT_H__ */