Refractor proposal

[QuantumEntangledAndy]

I was thinking about the current way we issue command to the camera because I found it difficult just to add another stream on one login (maybe my lack of rust-fu). Was thinking of how we could generalise the login and adding of tasks for a camera and thought of this pseudo code.

let camera = Camera::new(&addr, &channel);
let login_task = Login::new(username, pass);
let handle_login = camera.run_task(login_task); // Async
if let Err(e) =  handle_login.wait() { // Wait for async to finish
  return Err(e); // Login failed
}

let stream_1_task = Stream::new(gst_outputs, "mainStream");
let stream_2_task = Stream::new(gst_outputs, "subStream");
let handle_stream1 = camera.run_task(stream_1_task); // Async
let handle_stream2 = camera.run_task(stream_2_task); // Async
loop {
  match (handle_stream1.status(), handle_stream2.status()) { // status returns enum of Status::Error(e), Status::Running, Status::Complete
    (Status::Error(e), _ ) => {handle_stream2.abort(); return Err(e);},
    (_, Status::Error(e)) => {handle_stream1.abort(); return Err(e);},
    (Status::Complete, Status::Complete) => {break;},
    (_,_) => continue;,
  }
}

let logout_task = Logout::new(username, pass);
let handle_logout = camera.run_task(logout_task); // Async

let _ = handle_logout.wait();

Task should be a trait with bring_up, poll and tear_down all of which return the Status::Complete/Running/Error.

The camera.run_task should be a templated function that runs bring_up then loops poll until Status::Complete then runs tear_down on another thread.

Providing my rust-fu can make this happen what do you think about making this a PR?