Audio-synchronized widget linking

[Benoit Bovy]

Similarly to Ipywidgets's jsdlink, it would be nice if we could easily link an ipytone widget to any other widget, e.g.,

l = ipytone.sync_jsdlink((audio_widget, 'value'), (graphic_widget, 'value'), "8n")

that would do something like this on the JS side:

Tone.Transport.scheduleRepeat((time) => {
  Tone.Draw.schedule(() => {
    graphic_widget.set('value', audio_widget.get('value'));
    graphic_widget.save_changes();
  }, time);
}, '8n');

And l.unlink() would basically call Tone.Transport.clear() with the corresponding event id.

That would provide a high-level, convenient way of synchronizing any widget state (e.g., some ipycanvas drawing) with an audio signal on the JS side.

I'd be happy to hear your thoughts @davidbrochart! I guess that we could reuse the same approach that you used in #14?

[David Brochart]

So that would all happen in the front-end, or would there be a round-trip with the back-end?
I don't quite understand why time has anything to play with it, wouldn't the synchronization be instantaneous, whenever a change happens?

[Benoit Bovy]

So that would all happen in the front-end, or would there be a round-trip with the back-end?

All in the front-end, as I don't think any round-trip would be fast enough to result in an apparent synchronized state between a (DOM) widget and an audio signal.

I don't quite understand why time has anything to play with it, wouldn't the synchronization be instantaneous, whenever a change happens?

I'm not sure we'd be able to synchronize a widget trait value with an audio signal value that changes at the audio sample rate, so the idea is to force the synchronization to happen at some specific scheduled times (<< 44.1kHz), using Tone.Draw to improve the time accuracy.

[David Brochart]

Oh I didn't know Tone.Draw was something from tonejs 😄
Yes it makes total sense then.

[Benoit Bovy]

Closed in #70.