/* GStreamer * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu> * 2000 Wim Taymans <wtay@chello.be> * * gstinterface.h: Declarations of interface stuff * * 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_IMPLEMENTS_INTERFACE_H__ #define __GST_IMPLEMENTS_INTERFACE_H__ #include <gst/gstelement.h> G_BEGIN_DECLS #define GST_TYPE_IMPLEMENTS_INTERFACE \ (gst_implements_interface_get_type ()) #define GST_IMPLEMENTS_INTERFACE(obj) \ (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_IMPLEMENTS_INTERFACE, \ GstImplementsInterface)) #define GST_IS_IMPLEMENTS_INTERFACE(obj) \ (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_IMPLEMENTS_INTERFACE)) #define GST_IMPLEMENTS_INTERFACE_GET_CLASS(inst) \ (G_TYPE_INSTANCE_GET_INTERFACE ((inst), GST_TYPE_IMPLEMENTS_INTERFACE, \ GstImplementsInterfaceClass)) /** * GstImplementsInterface: * * Opaque #GstImplementsInterface structure. */ typedef struct _GstImplementsInterface GstImplementsInterface; typedef struct _GstImplementsInterfaceClass GstImplementsInterfaceClass; /* This small extra virtual function is here to provide an * interface functionality on a per-instance basis rather * than a per-class basis, which is the case for glib. */ struct _GstImplementsInterfaceClass { GTypeInterface parent; /* virtual functions */ gboolean (* supported) (GstImplementsInterface *iface, GType iface_type); gpointer _gst_reserved[GST_PADDING]; }; #define GST_IMPLEMENTS_INTERFACE_CHECK_INSTANCE_CAST(obj, type, cast_t) \ ((cast_t *) gst_implements_interface_cast ((obj), (type))) #define GST_IMPLEMENTS_INTERFACE_CHECK_INSTANCE_TYPE(obj, type) \ (gst_implements_interface_check ((obj), (type))) GType gst_implements_interface_get_type (void); /* wrapper functions to check for functionality implementation */ gboolean gst_element_implements_interface (GstElement *element, GType iface_type); gpointer gst_implements_interface_cast (gpointer from, GType type); gboolean gst_implements_interface_check (gpointer from, GType type); G_END_DECLS #endif /* __GST_IMPLEMENTS_INTERFACE_H__ */