expo-key-event/src/hooks/useKeyEventListener.web.ts

Provides an interface for reading key events such as from external bluetooth keyboards on Android, iOS and Web.

import { useCallback, useEffect } from "react";

import { KeyPressEvent } from "../ExpoKeyEvent.types";

/**
 *
 * @param listenOnMount Pass 'false' to prevent automatic key event listening
 * - Use startListening/stopListening to control the listener manually
 * @returns
 *
 */
export function useKeyEventListener(
  listener: (event: KeyPressEvent) => void,
  listenOnMount = true,
) {
  const onKeyDown = useCallback(
    (event: KeyboardEvent) => listener({ key: event.code }),
    [listener],
  );

  const startListening = useCallback(
    () => addEventListener("keydown", onKeyDown),
    [onKeyDown],
  );

  const stopListening = useCallback(
    () => removeEventListener("keydown", onKeyDown),
    [onKeyDown],
  );

  useEffect(() => {
    if (listenOnMount) startListening();

    return () => {
      stopListening();
    };
  }, [listenOnMount, startListening, stopListening]);

  return {
    /**
     * Start listening for key events
     */
    startListening,
    /**
     * Stop listening for key events
     */
    stopListening,
  };
}