☰

Key navigation

To be used for mapping keyboard arrow press events

Fra og med 02.10.2022. Se den nyeste version.

Dette script bør ikke installeres direkte. Det er et bibliotek, som andre scripts kan inkludere med metadirektivet // @require https://update.greatest.deepsurf.us/scripts/396703/1100259/Key%20navigation.js 

(() => {
  'use strict';

  const setUpKeyNavigation = ({
    onDownPressed,
    onLeftPressed,
    onRightPressed,
    onUpPressed,
    preventDefault,
    stopPropagation,
  }) => {
    document.addEventListener('keydown', (event) => {
      const operation = {
        ArrowDown: (e) => executeFn(onDownPressed, e),
        ArrowLeft: (e) => executeFn(onLeftPressed, e),
        ArrowRight: (e) => executeFn(onRightPressed, e),
        ArrowUp: (e) => executeFn(onUpPressed, e),
      }[event.key];

      if (operation) operation(event);

      preventDefault && event.preventDefault();
      stopPropagation && event.stopPropagation();
    });
  };

  const setUpAnchorNavigation = (selectorsMap) => {
    const downHref = getAnchorHref(selectorsMap.down);
    const leftHref = getAnchorHref(selectorsMap.left);
    const rightHref = getAnchorHref(selectorsMap.right);
    const upHref = getAnchorHref(selectorsMap.up);

    setUpKeyNavigation({
      onDownPressed: generateNavigationEvent(downHref),
      onLeftPressed: generateNavigationEvent(leftHref),
      onRightPressed: generateNavigationEvent(rightHref),
      onUpPressed: generateNavigationEvent(upHref),
    });
  };

  const getElement = (selector) => {
    return selector ? document.querySelector(selector) : undefined;
  };

  const getAnchorHref = (selector) => {
    return getElement(selector)?.href;
  };

  const generateNavigationEvent = (href) => {
    return href ? () => (location.href = href) : undefined;
  };

  const executeFn = (fn, ...parameters) => {
    return typeof fn === 'function' && fn(...parameters);
  };

  window.setUpAnchorNavigation = setUpAnchorNavigation;
  window.setUpKeyNavigation = setUpKeyNavigation;
})();