tabs/report/recorder.js

// recorder.js
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
  function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
  return new (P || (P = Promise))(function (resolve, reject) {
      function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
      function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
      function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
      step((generator = generator.apply(thisArg, _arguments || [])).next());
  });
};
const BLOB_TYPE = "video/webm";
class ScreenCastRecorder {
  /** True if the current browser likely supports screencasts. */
  static isSupportedBrowser() {
      return (navigator.mediaDevices != null &&
          navigator.mediaDevices.getUserMedia != null &&
          navigator.mediaDevices.getDisplayMedia != null &&
          MediaRecorder.isTypeSupported(BLOB_TYPE));
  }
  constructor({ recordAudio, onErrorOrStop }) {
      this.recordAudio = recordAudio;
      this.onErrorOrStopCallback = onErrorOrStop;
      this.inputStream = null;
      this.recordedChunks = [];
      this.mediaRecorder = null;
  }
  /**
   * This asynchronous method will initialize the screen recording object asking
   * for permissions to the user which are needed to start recording.
   */
  initialize() {
      return __awaiter(this, void 0, void 0, function* () {
          const desktopStream = yield navigator.mediaDevices.getDisplayMedia({
              video: true,
          });
          let tracks = desktopStream.getTracks();
          if (this.recordAudio) {
              const voiceStream = yield navigator.mediaDevices.getUserMedia({
                  video: false,
                  audio: true,
              });
              tracks = tracks.concat(voiceStream.getAudioTracks());
          }
          this.recordedChunks = [];
          this.inputStream = new MediaStream(tracks);
          this.mediaRecorder = new MediaRecorder(this.inputStream, {
              mimeType: BLOB_TYPE,
          });
          this.mediaRecorder.ondataavailable = e => this.recordedChunks.push(e.data);
      });
  }
  getState() {
      if (this.mediaRecorder) {
          return this.mediaRecorder.state;
      }
      return "inactive";
  }
  /**
   * This method will start the screen recording if the user has granted permissions
   * and the mediaRecorder has been initialized
   *
   * @returns {boolean}
   */
  start() {
      if (!this.mediaRecorder) {
          console.warn(`ScreenCastRecorder.start: mediaRecorder is null`);
          return false;
      }
      const logRecorderError = (e) => {
          console.warn(`mediaRecorder.start threw an error: ${e}`);
      };
      this.mediaRecorder.onerror = (e) => {
          logRecorderError(e);
          this.onErrorOrStopCallback();
      };
      this.mediaRecorder.onstop = () => this.onErrorOrStopCallback();
      try {
          this.mediaRecorder.start();
      }
      catch (e) {
          logRecorderError(e);
          return false;
      }
      return true;
  }
  /**
   * This method will stop recording and then return the generated Blob
   *
   * @returns {(Promise|undefined)}
   *  A Promise which will return the generated Blob
   *  Undefined if the MediaRecorder could not initialize
   */
  stop() {
      if (!this.mediaRecorder) {
          return undefined;
      }
      let resolver;
      const promise = new Promise(r => {
          resolver = r;
      });
      this.mediaRecorder.onstop = () => resolver();
      this.mediaRecorder.stop();
      if (this.inputStream) {
          this.inputStream.getTracks().forEach(s => s.stop());
          this.inputStream = null;
      }
      return promise.then(() => this.buildOutputBlob());
  }
  buildOutputBlob() {
      return new Blob(this.recordedChunks, { type: BLOB_TYPE });
  }
}