main.js

const electron = require("electron");
// Module to control application life.
const {app} = electron;
// Module to create native browser window.
const {BrowserWindow} = electron;

// Keep a global reference of the window object, if you don't, the window will
// be closed automatically when the JavaScript object is garbage collected.
let win;

function createWindow() {
  // Create the browser window.
    win = new BrowserWindow({width: 800, height: 600});

  // and load the index.html of the app.
    win.loadURL(`file://${__dirname}/index.html`);

  // Open the DevTools.
    win.webContents.openDevTools();

  // Emitted when the window is closed.
    win.on("closed", () => {
    // Dereference the window object, usually you would store windows
    // in an array if your app supports multi windows, this is the time
    // when you should delete the corresponding element.
        win = null;
    });
}

// This method will be called when Electron has finished
// initialization and is ready to create browser windows.
// Some APIs can only be used after this event occurs.
app.on("ready", createWindow);

// Quit when all windows are closed.
app.on("window-all-closed", () => {
  // On macOS it is common for applications and their menu bar
  // to stay active until the user quits explicitly with Cmd + Q
    if (process.platform !== "darwin") {
        app.quit();
    }
});

app.on("activate", () => {
  // On macOS it's common to re-create a window in the app when the
  // dock icon is clicked and there are no other windows open.
    if (win === null) {
        createWindow();
    }
});

// In this file you can include the rest of your app's specific main process
// code. You can also put them in separate files and require them here.