index.js

const {app, BrowserWindow, Menu, ipcMain} = require('electron')
const path = require('path')
const url = require('url')
var downloadsSaved = false;
// 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: 520, height: 680, icon: __dirname+'/assets/images/build/icon.png', resizable: false});
  // and load the index.html of the app.
  win.loadURL(url.format({
    pathname: path.join(__dirname, 'index.html'),
    protocol: 'file:',
    slashes: true
  }))

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

  win.on('close', (event) => {
    if(!downloadsSaved){
     event.preventDefault();
     win.webContents.send('saveDownloads');
    }
  });

  // 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
  })

const template = [
  {
    label: 'Edit',
    submenu: [
      {role: 'undo'},
      {role: 'redo'},
      {type: 'separator'},
      {role: 'cut'},
      {role: 'copy'},
      {role: 'paste'},
      {role: 'pasteandmatchstyle'},
      {role: 'delete'},
      {role: 'selectall'}
    ]
  }
]

if (process.platform === 'darwin') {
  template.unshift({
    label: app.getName(),
    submenu: [
      {role: 'about'},
      {type: 'separator'},
      {role: 'services', submenu: []},
      {type: 'separator'},
      {role: 'hide'},
      {role: 'hideothers'},
      {role: 'unhide'},
      {type: 'separator'},
      {role: 'quit'}
    ]
  })

  template[1].submenu.push(
    {type: 'separator'},
    {
      label: 'Speech',
      submenu: [
        {role: 'startspeaking'},
        {role: 'stopspeaking'}
      ]
    }
  )

}
Menu.setApplicationMenu(Menu.buildFromTemplate(template));
}

// 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', () => {
    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()
  }
})

ipcMain.on('quitApp',function(){
  downloadsSaved = true;
  app.quit();
});

// 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.