main.js

const electron = require('electron')
const {ipcMain} = require('electron');

// Module to control application life.
const app = electron.app
// Module to create native browser window.
const BrowserWindow = electron.BrowserWindow
const Menu = electron.Menu

// 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 mainWindow

function createWindow() {
  // Create the browser window.
  mainWindow = new BrowserWindow({ width: 1400, height: 600 })

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

  // Open the DevTools.
  mainWindow.webContents.openDevTools()

  // Emitted when the window is closed.
  mainWindow.on('closed', function () {
    // 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.
    mainWindow = 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', function () {
  // On OS X 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', function () {
  // On OS X 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 (mainWindow === 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.
ipcMain.on('update-menu', (event, arg) => {

  var template = [
    // {
    //   label: "File",
    //   submenu: [{
    //     label: 'Test',
    //     accelerator: 'CmdOrCtrl+M',
    //     click: function () { alert("Test") }
    //   }, {
    //       label: 'Open Google',
    //       accelerator: 'CmdOrCtrl+W',
    //       click: function () {
    //         //electron.shell.openExternal('http://google.com')
    //       }
    //     }]
    // },
    {
      label: "Panels",
      submenu: [
        {
          label: "Swap",
          accelerator: "Shift+CmdOrCtrl+P",
          click: () => {
            mainWindow.webContents.send("swap-panels");
          }
        }
      ]
    },
    {
      label: "Language",
      submenu: arg.languages.map(l => {
        return {
          label: l,
          click: () => {
            mainWindow.webContents.send('select-language', l);
          }
        };
      })
    },
    {
      label: "Theme",
      submenu: arg.themes.map(t => {
        return {
          label: t,
          click: () => {
            mainWindow.webContents.send('select-theme', t);
          }
        };
      })
    }
  ];

  const menu = Menu.buildFromTemplate(template)
  Menu.setApplicationMenu(menu)
})