youtube-music/plugins/touchbar/back.js

const {
	TouchBar
} = require('electron');
const {
	TouchBarButton,
	TouchBarLabel,
	TouchBarSpacer,
	TouchBarSegmentedControl,
	TouchBarScrubber
} = TouchBar;

// This selects the title
const titleSelector = '.title.style-scope.ytmusic-player-bar';

// These keys will be used to go backwards, pause and skip songs
const keys = ['k', 'space', 'j'];

const presskey = (window, key) => {
	window.webContents.sendInputEvent({
		type: 'keydown',
		keyCode: key
	});
};

// Grab the title using the selector
const getTitle = win => {
	return win.webContents.executeJavaScript(
		'document.querySelector(\'' + titleSelector + '\').innerText'
	).catch(error => {
		console.log(error);
	});
};

module.exports = win => {
	// Songtitle label
	const songTitle = new TouchBarLabel({
		label: ''
	});

	// The song control buttons (keys to press are in the same order)
	const buttons = new TouchBarSegmentedControl({
		mode: 'buttons',
		segments: [
			new TouchBarButton({
				label: '<'
			}),
			new TouchBarButton({
				label: '⏯️'
			}),
			new TouchBarButton({
				label: '>'
			})
		],
		change: i => presskey(win, keys[i])
	});

	// This is the touchbar object, this combines everything with proper layout
	const touchBar = new TouchBar({
		items: [
			new TouchBarScrubber({
				items: [songTitle],
				continuous: false
			}),
			new TouchBarSpacer({
				size: 'flexible'
			}),
			buttons
		]
	});

	// If the page title changes, update touchbar and song title
	win.on('page-title-updated', async () => {
		songTitle.label = await getTitle(win);
		win.setTouchBar(touchBar);
	});
};