main.js

// @ts-check
const { app, BrowserWindow } = require('electron');
let win;

function createWindow() {
  // Create the browser window.
  win = new BrowserWindow({
    width: 700,
    height: 700,
    backgroundColor: '#ffffff',
    icon: `file://${__dirname}/dist/browser/assets/icon/android-chrome-256x256.png`
  });

  win.loadURL(`file://${__dirname}/dist/browser/index.html`);
  //// uncomment below to open the DevTools.
  // win.webContents.openDevTools()
  // Event when the window is closed.
  win.on('closed', function() {
    win = null;
  });
}

// Create window on electron intialization
app.on('ready', createWindow);

// Quit when all windows are closed.
app.on('window-all-closed', function() {
  // On macOS specific close process
  if (process.platform !== 'darwin') {
    app.quit();
  }
});

app.on('activate', function() {
  // macOS specific close process
  if (win === null) {
    createWindow();
  }
});