components/mod.rs

In components/mod.rs, we implement a trait called Component:

pub trait Component {
  #[allow(unused_variables)]
  fn register_action_handler(&mut self, tx: UnboundedSender<Action>) -> Result<()> {
    Ok(())
  }
  #[allow(unused_variables)]
  fn register_config_handler(&mut self, config: Config) -> Result<()> {
    Ok(())
  }
  fn init(&mut self) -> Result<()> {
    Ok(())
  }
  fn handle_events(&mut self, event: Option<Event>) -> Result<Option<Action>> {
    let r = match event {
      Some(Event::Key(key_event)) => self.handle_key_events(key_event)?,
      Some(Event::Mouse(mouse_event)) => self.handle_mouse_events(mouse_event)?,
      _ => None,
    };
    Ok(r)
  }
  #[allow(unused_variables)]
  fn handle_key_events(&mut self, key: KeyEvent) -> Result<Option<Action>> {
    Ok(None)
  }
  #[allow(unused_variables)]
  fn handle_mouse_events(&mut self, mouse: MouseEvent) -> Result<Option<Action>> {
    Ok(None)
  }
  #[allow(unused_variables)]
  fn update(&mut self, action: Action) -> Result<Option<Action>> {
    Ok(None)
  }
  fn draw(&mut self, f: &mut Frame<'_>, rect: Rect) -> Result<()>;
}

I personally like keeping the functions for handle_events (i.e. event -> action mapping), dispatch (i.e. action -> state update mapping) and render (i.e. state -> drawing mapping) all in one file for each component of my application.

There’s also an init function that can be used to setup the Component when it is loaded.

The Home struct (i.e. the root struct that may hold other Components) will implement the Component trait. We’ll have a look at Home next.