books/client/ui/keyboard.js

module.exports = {
    bindKey(element, key, listener) {
        element.addEventListener('keydown', (e) => {
            if (key === this.getKey(e)) {
                listener(e);
            }
        })
    },

    getKey(e) {
        var keycode = e.keyCode || e.which;
        var key = this.keyMap[keycode] || String.fromCharCode(keycode);

        if(e.ctrlKey || e.metaKey) {
            // add ctrl+ the key
            key = 'ctrl+' + key;
        }
        if(e.shiftKey) {
            // add ctrl+ the key
            key = 'shift+' + key;
        }
        return key.toLowerCase();
    },

    keyMap: {
        8: 'backspace',
        9: 'tab',
        13: 'enter',
        16: 'shift',
        17: 'ctrl',
        91: 'meta',
        18: 'alt',
        27: 'escape',
        37: 'left',
        39: 'right',
        38: 'up',
        40: 'down',
        32: 'space'
    },
}