old_contents: const electron = require('electron')
  const app = electron.app
  const BrowserWindow = electron.BrowserWindow
  
  const path = require('path')
  const url = require('url')
  
  let mainWindow
  
  function createWindow() {
    mainWindow = new BrowserWindow({ width: 500, height: 200 })
    mainWindow.loadURL(url.format({
      pathname: path.join(__dirname, 'index.html'),
      protocol: 'file:',
      slashes: true
    }))
  
    mainWindow.webContents.openDevTools()
  
    mainWindow.on('closed', function () {
      mainWindow = null
    })
  }
  
  app.on('ready', createWindow)
  
  app.on('window-all-closed', function () {
    if (process.platform !== 'darwin') {
      app.quit()
    }
  })
  
  app.on('activate', function () {
    if (mainWindow === null) {
      createWindow()
    }
  })
  
  const ipc = require('electron').ipcMain
  var maya;
  
  ipc.on('portNum', function (event, arg) {
    const net = require('net');
    maya = new net.createConnection(arg);
  
    maya.on('error', function (e) {
      console.log(e);
      event.sender.send('connection-reply', e.errno);
    });
  
    maya.on('connect', function () {
      console.log('Connected - Maya');
      event.sender.send('connection-reply', 'Connected');
    });
  
    maya.on('data', function (data) {
      console.log('Maya: ' + data);
    });
  
    maya.on('close', function (data) {
      console.log('Maya: commandPort was closed.');
      event.sender.send('connection-reply', 'commandPort was closed.');
      // app.quit()
    });
  });
  
  ipc.on('MIDImessage', function (event, arg) {
    if (typeof maya === "undefined") {
      console.log("Not connection.")
    } else {
      var message = 'start,' + arg[1] + ',' + arg[2] / 127 + ',end';
      maya.write(message);
    }
  });
new_contents: const electron = require('electron')
  const app = electron.app
  const BrowserWindow = electron.BrowserWindow
  
  const path = require('path')
  const url = require('url')
  
  let mainWindow
  
  function createWindow() {
    mainWindow = new BrowserWindow({ width: 500, height: 200 })
    mainWindow.loadURL(url.format({
      pathname: path.join(__dirname, 'index.html'),
      protocol: 'file:',
      slashes: true
    }))
  
    //mainWindow.webContents.openDevTools()
  
    mainWindow.on('closed', function () {
      mainWindow = null
    })
  }
  
  app.on('ready', createWindow)
  
  app.on('window-all-closed', function () {
    if (process.platform !== 'darwin') {
      app.quit()
    }
  })
  
  app.on('activate', function () {
    if (mainWindow === null) {
      createWindow()
    }
  })
  
  const ipc = require('electron').ipcMain
  var maya;
  
  ipc.on('portNum', function (event, arg) {
    const net = require('net');
    maya = new net.createConnection(arg);
  
    maya.on('error', function (e) {
      console.log(e);
      event.sender.send('connection-reply', e.errno);
    });
  
    maya.on('connect', function () {
      console.log('Connected - Maya');
      event.sender.send('connection-reply', 'Connected');
    });
  
    maya.on('data', function (data) {
      console.log('Maya: ' + data);
    });
  
    maya.on('close', function (data) {
      console.log('Maya: commandPort was closed.');
      event.sender.send('connection-reply', 'commandPort was closed.');
      // app.quit()
    });
  });
  
  ipc.on('MIDImessage', function (event, arg) {
    if (typeof maya === "undefined") {
      console.log("Not connection.")
    } else {
      var message = 'start,' + arg[1] + ',' + arg[2] / 127 + ',end';
      maya.write(message);
    }
  });
  
subject: disable dev window