Trait InputHandler

Source

pub trait InputHandler: AsRcAny {
    // Required methods
    fn handle_input_event<'async_trait>(
        self: Rc<Self>,
        input_event: InputEvent,
    ) -> Pin<Box<dyn Future<Output = Vec<InputEvent>> + 'async_trait>>
       where Self: 'async_trait;
    fn set_handler_healthy(self: Rc<Self>);
    fn set_handler_unhealthy(self: Rc<Self>, msg: &str);

    // Provided method
    fn get_name(&self) -> &'static str { ... }
}

Expand description

An InputHandler dispatches InputEvents to an external service. It maintains service connections necessary to handle the events.

For example, an [ImeInputHandler] holds a proxy to IME and keyboard services.

InputHandlers process individual input events through [handle_input_event()], which can produce multiple events as an outcome. If the InputHandler sends an [InputEvent] to a service that consumes the event, then the InputHandler updates the [InputEvent.handled] accordingly.

§Notes

Callers should not invoke [handle_input_event()] concurrently since sequences of events must be preserved. The state created by event n may affect the interpretation of event n+1.
Callees should avoid blocking unnecessarily, as that prevents InputEvents from propagating to downstream handlers in a timely manner. See further discussion of blocking.

Required Methods§

Source

fn handle_input_event<'async_trait>( self: Rc<Self>, input_event: InputEvent, ) -> Pin<Box<dyn Future<Output = Vec<InputEvent>> + 'async_trait>>
where Self: 'async_trait,

Returns a vector of InputEvents to propagate to the next InputHandler.

The vector may be empty if, e.g., the handler chose to buffer the event.
The vector may have multiple events if, e.g.,
- the handler chose to release previously buffered events, or
- the handler unpacked a single event into multiple events