--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gstreamer_core/gst/gstinterface.h	Thu Dec 17 08:53:32 2009 +0200
@@ -0,0 +1,98 @@
+/* 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_IMPLEMENTS_INTERFACE_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_IMPLEMENTS_INTERFACE, \
+			    GstImplementsInterfaceClass))
+#define GST_IS_IMPLEMENTS_INTERFACE(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_IMPLEMENTS_INTERFACE))
+#define GST_IS_IMPLEMENTS_INTERFACE_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE ((klass), 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 */
+#ifdef __SYMBIAN32__
+IMPORT_C
+#endif
+
+gboolean gst_element_implements_interface     (GstElement *element,
+					       GType       iface_type);
+#ifdef __SYMBIAN32__
+IMPORT_C
+#endif
+
+gpointer gst_implements_interface_cast	      (gpointer    from,
+					       GType       type);
+#ifdef __SYMBIAN32__
+IMPORT_C
+#endif
+
+gboolean gst_implements_interface_check	      (gpointer    from,
+					       GType       type);
+
+G_END_DECLS
+
+#endif /* __GST_IMPLEMENTS_INTERFACE_H__ */