session-desktop/main.js

const electron = require('electron')
const app = electron.app
const BrowserWindow = electron.BrowserWindow
const path = require('path')
const url = require('url')
const fs = require('fs')
const autoUpdater = require('electron-updater').autoUpdater
const autoUpdaterInterval = 60 * 60 * 1000;
const ipc = electron.ipcMain;

app.setAppUserModelId('org.whispersystems.signal-desktop')

var shouldQuit = app.makeSingleInstance(function(commandLine, workingDirectory) {
  // Someone tried to run a second instance, we should focus our window
  if (mainWindow) {
    if (mainWindow.isMinimized()) mainWindow.restore();
    mainWindow.focus();
  }
  return true;
});

if (shouldQuit) {
  app.quit();
  return;
}

// Read package.json
const package_json = JSON.parse(fs.readFileSync(path.join(__dirname, 'package.json'), 'utf-8'))
const NODE_ENV = process.env.NODE_ENV || package_json.NODE_ENV || 'development';

// use a separate data directory for development
if (NODE_ENV !== 'production') {
  app.setPath('userData', path.join(app.getPath('appData'), 'Signal-' + NODE_ENV))
}
// 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: 800,
    height: 600,
    webPreferences: {
      nodeIntegration: false,
      sandbox: true,
      preload: path.join(__dirname, 'preload.js')
    }
  })

  // Load locale
  const locale = 'en'; // FIXME
  const localeData = JSON.parse(fs.readFileSync(path.join(__dirname, '_locales', locale, 'messages.json'), 'utf-8'))
  ipc.on('locale-data', function(event, arg) {
    event.returnValue = localeData;
  });

  // and load the index.html of the app.
  mainWindow.loadURL(url.format({
    pathname: path.join(__dirname, 'background.html'),
    protocol: 'file:',
    slashes: true,
    query: {
      node_env: NODE_ENV,
      locale: locale
    }
  }))

  // 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', function() {
  autoUpdater.addListener('update-downloaded', function() {
    autoUpdater.quitAndInstall()
  });
  autoUpdater.checkForUpdates();

  setInterval(function() { autoUpdater.checkForUpdates(); }, autoUpdaterInterval);
  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.