Plugin Architechture Draft

[TTWNO]

We could have a dedicated communication thread between the SR and plugins—which is running on a blocking task.

Basically:
Plugin <-> Comm. Thread <-> SR

The comm thread will also be how we run each plugins' functions.

So let's say we had a event(ev: Event) for each plugin, so they could, in theory, do something based on an event, we would write the following:

In the plugin, beep-on-blank-line

fn pre_event(comms: Pipe, ev: Event) {
   if Some(caret_moved) = TextCaretMoved::try_from(ev) {
     comms.send(OdiliaEvent::Sound("beep.wav"));
  }
}
fn post_event(ev: Event) {}

The comms thread passes events to the main Odilia even loop (it'll have a Sender<OdiliaEvent>).
It will also have a Received<AtspiEvent> to send events to each plugin:

// Vec<wasmer::Instance> 
for instance in instances {
  let func = instant.get_function(func_name)?;
  func(&event);
}

Finally, there is our atspi even loop:

comms_pipe.send("pre_event", &event);
// dispatch event
comms_pipe.send("post_event", &event);

I'm on mobile, so excuse the mess, but I think this is a good start. We need pre_* and post_* hooks for atspi events, Odilia events, SSIP commands, and module loading itself (basically init and cleanup).

Init should probably return a ModuleOptions

enum HookSystem {
  OdiliaEvents,
  AtspiEvents,
  SsipCommands,
  ModuleLoading
}
enum HookSide {
  Pre,
  Post,
  Core, // implement/override core functionality
}
struct Hook {
  side: HookSide,
  system: HookSystem,
}
struct ModuleOptions {
  hooks: Vec<Hook>,
  core_mod: bool, // is a core module that overrides standard behaviour. Without it, a Hook which uses rhe HookSide::Core value will be rejected. Also nore that only one core mod per system is permitted.
  id: String, // a unique string to identify your module. If not unique, Odilia will remove the module with the same name, and load this one. This should not change wirh versions.
  version: String, // the version of the plugin being used
}

Any comments? I realixe it'll be annoying to pass all those messages around, but I can't think of a better way.

EDIT: Tired and on mobile, will fix up grammsr/spelling later.

[TTWNO]

Another thing to consider: threre is a reasonable chance that plugins may want to communicate with one another. I'm not sure how to cover this case easily.