Pointer to a DrawHandlerDesc data structure, into which the macro will
copy the remaining parameters.
Pointer to the callback function that BREW will call when drawing the
the decorator. This routine will override the default drawing routine
for the decorator, allowing an application to apply a custom rendering
technique to the widget wrapped by the draw decorator object.
A pointer to private data allocated and managed by the caller that
has registered the draw handler with the draw decorator. This data
pointer is passed into the draw handler, as well as the free handler,
providing each of these callbacks with access to this private storage.
Pointer to the callback function that BREW will call when freeing the
memory associated with a draw decorator upon releasing the object.
This gives the draw decorator the opportunity to release any private
"deep" storage that may have been allocated by the object.