electron.js

const electron = require('electron')
const app = electron.app
const BrowserWindow = electron.BrowserWindow
const Menu = electron.Menu
const path = require('path')
const isDev = require('electron-is-dev')

let mainWindow

const gotTheLock = app.requestSingleInstanceLock()

if (!gotTheLock) {
  app.quit()
  return
}

app.on('second-instance', () => {
  // Someone tried to run a second instance, we should focus our window.
  if (mainWindow) {
    if (mainWindow.isMinimized()) mainWindow.restore()
    mainWindow.focus()
  }
})

function isWin() {
  return process.platform === 'win32'
}

function setDarwinMenu() {
  const name = app.getName()
  const template = [
    {
      label: app.name,
      submenu: [
        {
          label: 'About ' + name,
          role: 'about'
        },
        {
          label: 'Quit',
          accelerator: 'Command+Q',
          click() {
            app.quit()
          }
        }
      ]
    },
    {
      label: 'Edit',
      submenu: [
        { label: 'Undo', accelerator: 'CmdOrCtrl+Z', selector: 'undo:' },
        { label: 'Redo', accelerator: 'Shift+CmdOrCtrl+Z', selector: 'redo:' },
        { type: 'separator' },
        { label: 'Cut', accelerator: 'CmdOrCtrl+X', selector: 'cut:' },
        { label: 'Copy', accelerator: 'CmdOrCtrl+C', selector: 'copy:' },
        { label: 'Paste', accelerator: 'CmdOrCtrl+V', selector: 'paste:' },
        {
          label: 'Select All',
          accelerator: 'CmdOrCtrl+A',
          selector: 'selectAll:'
        }
      ]
    }
  ]

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

function createWindow() {
  if (process.platform === 'darwin') {
    setDarwinMenu()
  }

  mainWindow = new BrowserWindow({
    width: isWin() ? 380 : 358,
    height: isWin() ? 665 : 610,
    webPreferences: { preload: path.join(__dirname, 'preload.js') }
  })
  mainWindow.removeMenu() // only work for linux and windows
  if (isDev) {
    mainWindow
      .loadURL('http://localhost:3002')
      .then(() => console.log('url loaded'))
  } else {
    mainWindow
      .loadFile(path.join(__dirname, './build/index.html'))
      .then(() => console.log('index.html loaded'))
  }

  if (isDev) {
    // Open the DevTools.
    //BrowserWindow.addDevToolsExtension('<location to your react chrome extension>');
    mainWindow.webContents.openDevTools()
  }

  mainWindow.on('closed', () => (mainWindow = null))

  electron.globalShortcut.register('CommandOrControl+O', () => {
    mainWindow.openDevTools()
  })
  electron.globalShortcut.register('CommandOrControl+Shift+I', () => {
    mainWindow.openDevTools()
  })
}

const restoreInstance = () => {
  if (mainWindow.isMinimized()) {
    mainWindow.restore()
  }
  mainWindow.show()
}

const activateInstance = e => {
  if (e) e.preventDefault()
  if (!mainWindow) {
    createWindow()
    return
  }
  restoreInstance()
}

app.on('ready', async () => {
  createWindow()
})

app.on('window-all-closed', () => {
  if (process.platform !== 'darwin') {
    app.quit()
  }
})

app.on('activate', activateInstance)