Merge pull request #10896 from electron/update_desktop_capturer

Update desktop capturer to ES6

lib/browser/desktop-capturer.js

@@ -1,23 +1,23 @@
 'use strict'
 
-const ipcMain = require('electron').ipcMain
+const {ipcMain} = require('electron')
-const desktopCapturer = process.atomBinding('desktop_capturer').desktopCapturer
+const {desktopCapturer} = process.atomBinding('desktop_capturer')
 
-var deepEqual = function (opt1, opt2) {
+const deepEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b)
-  return JSON.stringify(opt1) === JSON.stringify(opt2)
-}
 
 // A queue for holding all requests from renderer process.
-var requestsQueue = []
+let requestsQueue = []
 
-ipcMain.on('ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES', function (event, captureWindow, captureScreen, thumbnailSize, id) {
+const electronSources = 'ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES'
-  var request
+const capturerResult = (id) => `ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_${id}`
-  request = {
+
-    id: id,
+ipcMain.on(electronSources, (event, captureWindow, captureScreen, thumbnailSize, id) => {
+  const request = {
+    id,
     options: {
-      captureWindow: captureWindow,
+      captureWindow,
-      captureScreen: captureScreen,
+      captureScreen,
-      thumbnailSize: thumbnailSize
+      thumbnailSize
     },
     webContents: event.sender
   }
@@ -28,45 +28,38 @@ ipcMain.on('ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES', function (event, cap
 
   // If the WebContents is destroyed before receiving result, just remove the
   // reference from requestsQueue to make the module not send the result to it.
-  event.sender.once('destroyed', function () {
+  event.sender.once('destroyed', () => {
     request.webContents = null
   })
 })
 
-desktopCapturer.emit = function (event, name, sources) {
+desktopCapturer.emit = (event, name, sources) => {
   // Receiving sources result from main process, now send them back to renderer.
-  var handledRequest, i, len, ref, ref1, request, result, source, unhandledRequestsQueue
+  const handledRequest = requestsQueue.shift()
-  handledRequest = requestsQueue.shift(0)
+  const handledWebContents = handledRequest.webContents
-  result = (function () {
+  const unhandledRequestsQueue = []
-    var i, len, results
+
-    results = []
+  const result = sources.map(source => {
-    for (i = 0, len = sources.length; i < len; i++) {
+    return {
-      source = sources[i]
-      results.push({
       id: source.id,
       name: source.name,
       thumbnail: source.thumbnail.toDataURL()
-      })
     }
-    return results
+  })
-  })()
+
-  if ((ref = handledRequest.webContents) != null) {
+  if (handledWebContents) {
-    ref.send('ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_' + handledRequest.id, result)
+    handledWebContents.send(capturerResult(handledRequest.id), result)
   }
 
-  // Check the queue to see whether there is other same request. If has, handle
+  // Check the queue to see whether there is another identical request & handle
-  // it for reducing redunplicated `desktopCaptuer.startHandling` calls.
+  requestsQueue.forEach(request => {
-  unhandledRequestsQueue = []
+    const webContents = request.webContents
-  for (i = 0, len = requestsQueue.length; i < len; i++) {
-    request = requestsQueue[i]
     if (deepEqual(handledRequest.options, request.options)) {
-      if ((ref1 = request.webContents) != null) {
+      if (webContents) webContents.send(capturerResult(request.id), result)
-        ref1.send('ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_' + request.id, result)
-      }
     } else {
       unhandledRequestsQueue.push(request)
     }
-  }
+  })
   requestsQueue = unhandledRequestsQueue
 
   // If the requestsQueue is not empty, start a new request handling.

lib/renderer/api/desktop-capturer.js

@@ -1,46 +1,43 @@
-const ipcRenderer = require('electron').ipcRenderer
+const {ipcRenderer, nativeImage} = require('electron')
-const nativeImage = require('electron').nativeImage
 
-var nextId = 0
+const includes = [].includes
-var includes = [].includes
+let currentId = 0
 
-var getNextId = function () {
+const incrementId = () => {
-  return ++nextId
+  currentId += 1
+  return currentId
 }
 
-// |options.type| can not be empty and has to include 'window' or 'screen'.
+// |options.types| can't be empty and must be an array
-var isValid = function (options) {
+function isValid (options) {
-  return ((options != null ? options.types : void 0) != null) && Array.isArray(options.types)
+  const types = options ? options.types : undefined
+  return Array.isArray(types)
 }
 
 exports.getSources = function (options, callback) {
-  var captureScreen, captureWindow, id
+  if (!isValid(options)) return callback(new Error('Invalid options'))
-  if (!isValid(options)) {
+  const captureWindow = includes.call(options.types, 'window')
-    return callback(new Error('Invalid options'))
+  const captureScreen = includes.call(options.types, 'screen')
-  }
+
-  captureWindow = includes.call(options.types, 'window')
-  captureScreen = includes.call(options.types, 'screen')
   if (options.thumbnailSize == null) {
     options.thumbnailSize = {
       width: 150,
       height: 150
     }
   }
-  id = getNextId()
+
+  const id = incrementId()
   ipcRenderer.send('ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES', captureWindow, captureScreen, options.thumbnailSize, id)
-  return ipcRenderer.once('ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_' + id, function (event, sources) {
+  return ipcRenderer.once(`ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_${id}`, (event, sources) => {
-    var source
+    callback(null, (() => {
-    callback(null, (function () {
+      const results = []
-      var i, len, results
+      sources.forEach(source => {
-      results = []
-      for (i = 0, len = sources.length; i < len; i++) {
-        source = sources[i]
         results.push({
           id: source.id,
           name: source.name,
           thumbnail: nativeImage.createFromDataURL(source.thumbnail)
         })
-      }
+      })
       return results
     })())
   })