electron/lib/browser/desktop-capturer.js
2018-09-14 14:57:01 +10:00

71 lines
2.3 KiB
JavaScript

'use strict'
const { ipcMain } = require('electron')
const { desktopCapturer } = process.atomBinding('desktop_capturer')
const deepEqual = (a, b) => JSON.stringify(a) === JSON.stringify(b)
// A queue for holding all requests from renderer process.
let requestsQueue = []
const electronSources = 'ELECTRON_BROWSER_DESKTOP_CAPTURER_GET_SOURCES'
const capturerResult = (id) => `ELECTRON_RENDERER_DESKTOP_CAPTURER_RESULT_${id}`
ipcMain.on(electronSources, (event, captureWindow, captureScreen, thumbnailSize, id) => {
const request = {
id,
options: {
captureWindow,
captureScreen,
thumbnailSize
},
webContents: event.sender
}
requestsQueue.push(request)
if (requestsQueue.length === 1) {
desktopCapturer.startHandling(captureWindow, captureScreen, thumbnailSize)
}
// 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', () => {
request.webContents = null
})
})
desktopCapturer.emit = (event, name, sources) => {
// Receiving sources result from main process, now send them back to renderer.
const handledRequest = requestsQueue.shift()
const handledWebContents = handledRequest.webContents
const unhandledRequestsQueue = []
const result = sources.map(source => {
return {
id: source.id,
name: source.name,
thumbnail: source.thumbnail.toDataURL(),
display_id: source.display_id
}
})
if (handledWebContents) {
handledWebContents.send(capturerResult(handledRequest.id), result)
}
// Check the queue to see whether there is another identical request & handle
requestsQueue.forEach(request => {
const webContents = request.webContents
if (deepEqual(handledRequest.options, request.options)) {
if (webContents) webContents.send(capturerResult(request.id), result)
} else {
unhandledRequestsQueue.push(request)
}
})
requestsQueue = unhandledRequestsQueue
// If the requestsQueue is not empty, start a new request handling.
if (requestsQueue.length > 0) {
const { captureWindow, captureScreen, thumbnailSize } = requestsQueue[0].options
return desktopCapturer.startHandling(captureWindow, captureScreen, thumbnailSize)
}
}