userscript youtube.com toggle controller/chrome/overlay

togglechrome.js

let revoke = (
function() {
    let display_on = false;
    const selectors = `
        .ytp-chrome-top
        .ytp-chrome-bottom
        .ytp-gradient-top
        .ytp-gradient-bottom`.split('\n').map(s => s.trim()).filter(s => s);
    
    function toggleYouTubeControls() {
        if(selectors.map(selector => {
            const element = document.querySelector(selector);
            if (element) {
                element.style.display = display_on ? '' : 'none';
                return true
            }
        }).some(_=>_)){
          display_on = !display_on
        }
    }
    
    function keyListener(event) {
        if (event.altKey && event.key === 'h') {
            toggleYouTubeControls();
        }
    }
    
    document.addEventListener('keydown', keyListener);
    
    return function revoke() {
        document.removeEventListener('keydown', keyListener);
    };
})();