mlt_repository.[hc]: implement the metadata registration and lookup interface

[melted] / src / framework / mlt_repository.h

diff --git a/src/framework/mlt_repository.h b/src/framework/mlt_repository.h
index 6517030..e7b0c67 100644 (file)
--- a/src/framework/mlt_repository.h
+++ b/src/framework/mlt_repository.h
@@ -2,6 +2,7 @@
  * repository.h -- provides a map between service and shared objects
  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
  * Author: Charles Yates <charles.yates@pandora.be>
+ * Contributor: Dan Dennedy <dan@dennedy.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -29,25 +30,37 @@
 
 typedef struct mlt_repository_s *mlt_repository;
 
-/** This macro can be used to register services if the function is declared as 
-*   void mlt_register( mlt_repository )
+/** This callback is the main entry point into a module, which must be exported
+    with the symbol "mlt_register".
+    Inside the callback, the module registers the additional callbacks below.
+*/
+
+typedef void ( *mlt_repository_callback )( mlt_repository );
+
+/** These are callback functions that modules implement to construct services
+    and metadata.
+*/
+typedef void *( *mlt_register_callback )( mlt_profile, mlt_service_type, const char * /* service name */, void * /* arg */ );
+typedef mlt_properties ( *mlt_metadata_callback )( mlt_service_type, const char * /* service name */, void * /* callback_data */ );
+
+/** These convenience macros can be used to register services in a more declarative manner.
 */
 #define MLT_REPOSITORY void mlt_register( mlt_repository repository )
-#define MLT_REGISTER( type, service, symbol  ) ( mlt_repository_register( repository, (type), (service), (symbol) ) )
-#define MLT_REGISTER_METADATA( type, service, properties  ) ( mlt_repository_register_metadata( repository, (type), (service), (properties) ) )
+#define MLT_REGISTER( type, service, symbol  ) ( mlt_repository_register( repository, (type), (service), ( mlt_register_callback )(symbol) ) )
+#define MLT_REGISTER_METADATA( type, service, callback, data ) ( mlt_repository_register_metadata( repository, (type), (service), ( mlt_metadata_callback )(callback), (data) ) )
 
 /** Public functions.
 */
 
 extern mlt_repository mlt_repository_init( const char *directory );
-extern void mlt_repository_register( mlt_repository self, mlt_service_type service_type, const char *service, void *symbol );
+extern void mlt_repository_register( mlt_repository self, mlt_service_type service_type, const char *service, mlt_register_callback );
 extern void *mlt_repository_create( mlt_repository self, mlt_profile profile, mlt_service_type type, const char *service, void *arg ); 
 extern void mlt_repository_close( mlt_repository self );
 extern mlt_properties mlt_repository_consumers( mlt_repository self );
 extern mlt_properties mlt_repository_filters( mlt_repository self );
 extern mlt_properties mlt_repository_producers( mlt_repository self );
 extern mlt_properties mlt_repository_transitions( mlt_repository self );
-extern void mlt_repository_register_metadata( mlt_repository self, mlt_service_type type, const char *service, mlt_properties metadata );
+extern void mlt_repository_register_metadata( mlt_repository self, mlt_service_type type, const char *service, mlt_metadata_callback, void *callback_data );
 extern mlt_properties mlt_repository_metadata( mlt_repository self, mlt_service_type type, const char *service );
 
 #endif