APTR handle = OpenDir(STRPTR name, int mode, struct hwTagList *tags);
OpenDir()implementation has to check whether your plugin wants to handle this directory or not. If your plugin wants to handle this directory, your
OpenDir()implementation needs to open it and return a handle back to Hollywood. Otherwise
NULL. The handle returned by this function is an opaque data type only your plugin knows about. Hollywood will pass this handle to you whenever it wants to get the next object from this directory.
tags parameters are currently unused and reserved for future use.
NULLif your plugin doesn't want to handle this directory