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helgoboss / reaper-rs

Rust bindings for the REAPER C++ API
MIT License
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How to get notified when tracks/effects change? #36

Closed Boscop closed 3 years ago

Boscop commented 3 years ago

Before reaper-rs existed I wrote a VST plugin that I now want to port to using reaper-rs.. I've been using my own hacky Reaper API bindings, and they worked well for calls but I couldn't figure out how to get notified when the configuration of tracks or effect plugins changes. I had tried to register my VST as a control surface but it wasn't being called for some reason. (This was my attempt at writing a Rust API for registering a control surface, and then in my VST state I'd have a member surface: MyControlSurfaceHandle<MySurface> and this impl:

impl MyControlSurface for MySurface {
    fn log(&mut self, s: &str) {
        info!("{}", s);
    }
}

But it logged nothing when I loaded the VST in Reaper.. Any idea why it didn't work?)

How would it be done with reaper-rs? I see that in the readme you have an example like this: rx.track_removed().subscribe(|t| println!("Track {:?} removed", t)); But that's part of the unreleased crate for which there is no doc. It looks like the relevant events are all handled already: https://github.com/helgoboss/reaper-rs/blob/faf49999c7a76cb82a613c80f73334c225c9f823/main/rx/src/control_surface.rs#L33-L36 So I guess my main question is: How can I use this? / Where should I get the rx handle from? :) And is there anything else I need to take into account (e.g. regarding when those events are sent)?

helgoboss commented 3 years ago

Better don't use reaper-high. The high stands for highly unstable ;)

You can do that in a much more stable way using the medium-level API: ReaperSession::plugin_register_add_csurf_inst(). This method also has an example doc.

Not sure why yours didn't work but getting the control surface stuff to work in Rust was quite some effort because it's interfacing with C++ virtual classes.

Boscop commented 3 years ago

Thanks for the quick reply :) So it seems like I then only need to impl set_track_list_change and ext_set_fx_change to be notified whenever a track or effect is added/removed/renamed?

helgoboss commented 3 years ago

If you don't mind which track, yes. REAPER calls set_track_list_change in many situations. You need some more elaborate mechanism to detect what has been changed. This is only in reaper-high at the moment. You can have a look here to see how it works: ChangeDetectionMiddleware.

Boscop commented 3 years ago

Thanks, and which value should I return from ext_set_fx_change?