Re: implementation plan for music streams

[Han-Wen Nienhuys]

Erik Sandberg wrote:
> Hi,
>
> Here's my plan on how to front-port music streams to the 2.9 branch.
>
> 1. Implement classes Dispatcher, Stream_event, Listener (move modules from my 
> thesis fork)
> 2. Add dispatchers event_source_, and possibly events_below_, to Context 
> class.
> 3. Make Context::try_music send stream events to the event_source_.
> 4. Refactor certain iterators (apply-context, time-scaled-music), so that all 
> music events are sent to bottom contexts.
> 5. Refactor commands such as lyricsto, to eliminate busy-playing-event etc.
> 6. There should now be no dependency on the try_music return value, so it 
> should be safe to make Translator_group::try_music an event handler.
> 7. Add stream events for CreateContext, ChangeContext, Prepare, OneTimeStep, 
> SetProperty, etc. These are quite easy to implement.
> 8. Various cleanups; e.g., remove the unneeded Score_context class.
>
> Comments?

I'd start with 4. because they're independent from the rest, and we can 
readily test the rest of those.


--

Han-Wen Nienhuys - address@hidden - http://www.xs4all.nl/~hanwen

LilyPond Software Design
 -- Code for Music Notation
http://www.lilypond-design.com