Struct KeypadListener

pub struct KeypadListener<'a> { /* private fields */ }

Polls the keypad.

use ndless_async::task::{block_on, AsyncListeners};
use ndless_async::keypad::{KeypadListener, KeyState};
use ndless_async::StreamExt;

let listeners = AsyncListeners::new();
block_on(&listeners, async {
    let keypad = KeypadListener::new(&listeners.timer());
    let mut stream = keypad.stream();
    while let Some(event) = stream.next().await {
        println!(
            "Key {:?} was {}",
            event.key,
            if event.state == KeyState::Released {
                "released"
            } else {
                "pressed"
            }
        );
    }
});

Implementations

impl<'a> KeypadListener<'a>

pub fn new(timer_listener: &'a TimerListener) -> Self

Creates a new keypad listener that polls the keypad 30 times per second. Use the new_with_* series of functions to change the polling rate. You may also poll the keypad manually by using new_manually_polled.

pub fn new_with_hz(timer_listener: &'a TimerListener, hz: u32) -> Self

Creates a new keypad listener that polls the keypad with the specified number of events per second.

pub fn new_with_ms(timer_listener: &'a TimerListener, dur: u32) -> Self

Creates a new keypad listener that polls the keypad every dur milliseconds.

pub fn new_with_rate(timer_listener: &'a TimerListener, dur: Duration) -> Self

Creates a new keypad listener that polls the keypad with the specified interval.

pub fn new_with_ticks(timer_listener: &'a TimerListener, ticks: u32) -> Self

Creates a new keypad listener that polls the keypad every specified ticks.

pub fn new_manually_polled() -> Self

Creates a new keypad listener that isn’t automatically polled. You’ll need to use poll periodically to poll the keypad.

pub fn poll(&self)

Polls the keypad. You shouldn’t have to use this normally.

pub fn stream(&self) -> KeyStream

Each call to stream returns a unique stream, meaning that calling it from different tasks will allow each task to receive every event. A buffer of 100 keypress events is allocated. Use stream_with_buffer to specify a custom size.

Warning

Don’t use this function in a loop. You should call stream before the loop, or use a stream combinator such as for_each. Failure to do so will result in lost events and less efficient code.

pub fn stream_with_buffer(&self, size: usize) -> KeyStream

This is the same as stream, except that it allows specifying a buffer size other than the default of 100.

Warning

Don’t use this function in a loop. You should call stream_with_buffer before the loop, or use a stream combinator such as for_each. Failure to do so will result in lost events and less efficient code.

pub fn list_keys(&self) -> Ref<'_, Vec<Key>>

Returns a Ref to the keys that are currently pressed. You must drop this reference either explicitly or by ending the current scope before .awaiting something. The program will crash otherwise.