electron-quick-start-oop.js

const electron = require('electron');
const { app, BrowserWindow } = electron;
const path = require('path');
const url = require('url');

class Application {
	constructor() {
		this.windows = {};
		app.on('ready', () => this.createWindow('main'));
		app.on('activate', () => this.createWindow('main'));
		app.on('window-all-closed', function () {
			if (process.platform !== 'darwin') {
				app.quit();
			}
		});		
	}

	createWindow(name) {
		if(!this.windows.hasOwnProperty(name)) {
			const window = this.windows[name] = new BrowserWindow({ width: 800, height: 600 });
			window.loadURL(url.format({
				pathname: path.join(__dirname, 'gui', 'index.html'),
				protocol: 'file:',
				slashes: true
			}));
			window.webContents.openDevTools();
			window.on('closed', () => {
				this.windows[name] = null;
			});
		}
	}
}

new Application();