gecko-dev/mobile/android/modules/WebrtcUI.jsm

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";

var EXPORTED_SYMBOLS = ["WebrtcUI"];

const { XPCOMUtils } = ChromeUtils.import(
  "resource://gre/modules/XPCOMUtils.jsm"
);

XPCOMUtils.defineLazyModuleGetters(this, {
  DoorHanger: "resource://gre/modules/Prompt.jsm",
  Notifications: "resource://gre/modules/Notifications.jsm",
  RuntimePermissions: "resource://gre/modules/RuntimePermissions.jsm",
  Services: "resource://gre/modules/Services.jsm",
});

XPCOMUtils.defineLazyServiceGetter(
  this,
  "MediaManagerService",
  "@mozilla.org/mediaManagerService;1",
  "nsIMediaManagerService"
);
XPCOMUtils.defineLazyServiceGetter(
  this,
  "ParentalControls",
  "@mozilla.org/parental-controls-service;1",
  "nsIParentalControlsService"
);

var Strings = {};

XPCOMUtils.defineLazyGetter(Strings, "brand", _ =>
  Services.strings.createBundle("chrome://branding/locale/brand.properties")
);
XPCOMUtils.defineLazyGetter(Strings, "browser", _ =>
  Services.strings.createBundle("chrome://browser/locale/browser.properties")
);

var WebrtcUI = {
  _notificationId: null,

  // Add-ons can override stock permission behavior by doing:
  //
  //   var stockObserve = WebrtcUI.observe;
  //
  //   webrtcUI.observe = function(aSubject, aTopic, aData) {
  //     switch (aTopic) {
  //      case "PeerConnection:request": {
  //        // new code.
  //        break;
  //      ...
  //      default:
  //        return stockObserve.call(this, aSubject, aTopic, aData);
  //
  // See browser/modules/webrtcUI.jsm for details.

  observe: function(aSubject, aTopic, aData) {
    if (aTopic === "getUserMedia:ask-device-permission") {
      RuntimePermissions.waitForPermissions(
        this._determineNeededRuntimePermissions(aData)
      ).then(_ => {
        Services.obs.notifyObservers(
          aSubject,
          "getUserMedia:got-device-permission"
        );
      });
    } else if (aTopic === "getUserMedia:request") {
      RuntimePermissions.checkPermissions(
        this._determineNeededRuntimePermissions(aSubject)
      ).then(permissionGranted => {
        if (permissionGranted) {
          WebrtcUI.handleGumRequest(aSubject, aTopic, aData);
        } else {
          Services.obs.notifyObservers(
            null,
            "getUserMedia:response:deny",
            aSubject.callID
          );
        }
      });
    } else if (aTopic === "PeerConnection:request") {
      this.handlePCRequest(aSubject, aTopic, aData);
    } else if (aTopic === "recording-device-events") {
      this.notify();
    } else if (aTopic === "VideoCapture:Paused") {
      if (this._notificationId) {
        Notifications.cancel(this._notificationId);
        this._notificationId = null;
      }
    } else if (aTopic === "VideoCapture:Resumed") {
      this.notify();
    }
  },

  notify: function() {
    let windows = MediaManagerService.activeMediaCaptureWindows;
    let count = windows.length;
    let msg = {};
    if (count == 0) {
      if (this._notificationId) {
        Notifications.cancel(this._notificationId);
        this._notificationId = null;
      }
    } else {
      let notificationOptions = {
        title: Strings.brand.GetStringFromName("brandShortName"),
        when: null, // hide the date row
        light: [0xff9500ff, 1000, 1000],
        ongoing: true,
      };

      let cameraActive = false;
      let audioActive = false;
      for (let i = 0; i < count; i++) {
        let win = windows.queryElementAt(i, Ci.nsIDOMWindow);
        let hasCamera = {};
        let hasMicrophone = {};
        MediaManagerService.mediaCaptureWindowState(
          win,
          hasCamera,
          hasMicrophone
        );
        if (hasCamera.value != MediaManagerService.STATE_NOCAPTURE) {
          cameraActive = true;
        }
        if (hasMicrophone.value != MediaManagerService.STATE_NOCAPTURE) {
          audioActive = true;
        }
      }

      if (cameraActive && audioActive) {
        notificationOptions.message = Strings.browser.GetStringFromName(
          "getUserMedia.sharingCameraAndMicrophone.message2"
        );
        notificationOptions.icon = "drawable:alert_mic_camera";
      } else if (cameraActive) {
        notificationOptions.message = Strings.browser.GetStringFromName(
          "getUserMedia.sharingCamera.message2"
        );
        notificationOptions.icon = "drawable:alert_camera";
      } else if (audioActive) {
        notificationOptions.message = Strings.browser.GetStringFromName(
          "getUserMedia.sharingMicrophone.message2"
        );
        notificationOptions.icon = "drawable:alert_mic";
      } else {
        // somethings wrong. lets throw
        throw new Error("Couldn't find any cameras or microphones being used");
      }

      if (this._notificationId) {
        Notifications.update(this._notificationId, notificationOptions);
      } else {
        this._notificationId = Notifications.create(notificationOptions);
      }
      if (count > 1) {
        msg.count = count;
      }
    }
  },

  handlePCRequest: function handlePCRequest(aSubject, aTopic, aData) {
    aSubject = aSubject.wrappedJSObject;
    let { callID } = aSubject;
    // Also available: windowID, isSecure, innerWindowID. For contentWindow do:
    //
    //   let contentWindow = Services.wm.getOuterWindowWithId(windowID);

    Services.obs.notifyObservers(null, "PeerConnection:response:allow", callID);
  },

  handleGumRequest: function handleGumRequest(aSubject, aTopic, aData) {
    let constraints = aSubject.getConstraints();
    let contentWindow = Services.wm.getOuterWindowWithId(aSubject.windowID);

    contentWindow.navigator.mozGetUserMediaDevices(
      constraints,
      function(devices) {
        if (!ParentalControls.isAllowed(ParentalControls.CAMERA_MICROPHONE)) {
          Services.obs.notifyObservers(
            null,
            "getUserMedia:response:deny",
            aSubject.callID
          );
          WebrtcUI.showBlockMessage(contentWindow, devices);
          return;
        }

        WebrtcUI.prompt(
          contentWindow,
          aSubject.callID,
          constraints.audio,
          constraints.video,
          devices
        );
      },
      function(error) {
        Cu.reportError(error);
      },
      aSubject.innerWindowID,
      aSubject.callID
    );
  },

  getDeviceButtons: function(audioDevices, videoDevices, aCallID, aPrincipal) {
    return [
      {
        label: Strings.browser.GetStringFromName(
          "getUserMedia.denyRequest.label"
        ),
        callback: function() {
          Services.obs.notifyObservers(
            null,
            "getUserMedia:response:deny",
            aCallID
          );
        },
      },
      {
        label: Strings.browser.GetStringFromName(
          "getUserMedia.shareRequest.label"
        ),
        callback: function(checked /* ignored */, inputs) {
          let allowedDevices = Cc["@mozilla.org/array;1"].createInstance(
            Ci.nsIMutableArray
          );

          let audioId = 0;
          if (inputs && inputs.audioDevice != undefined) {
            audioId = inputs.audioDevice;
          }
          if (audioDevices[audioId]) {
            allowedDevices.appendElement(audioDevices[audioId]);
          }

          let videoId = 0;
          if (inputs && inputs.videoSource != undefined) {
            videoId = inputs.videoSource;
          }
          if (videoDevices[videoId]) {
            allowedDevices.appendElement(videoDevices[videoId]);
            let perms = Services.perms;
            // Although the lifetime is "session" it will be removed upon
            // use so it's more of a one-shot.
            perms.addFromPrincipal(
              aPrincipal,
              "MediaManagerVideo",
              perms.ALLOW_ACTION,
              perms.EXPIRE_SESSION
            );
          }

          Services.obs.notifyObservers(
            allowedDevices,
            "getUserMedia:response:allow",
            aCallID
          );
        },
        positive: true,
      },
    ];
  },

  _determineNeededRuntimePermissions: function(aSubject) {
    let permissions = [];

    let constraints;
    if (typeof aSubject === "string") {
      constraints = {
        video: aSubject === "video" || aSubject === "all",
        audio: aSubject === "audio" || aSubject === "all",
      };
    } else {
      constraints = aSubject.getConstraints();
    }

    if (constraints.video) {
      permissions.push(RuntimePermissions.CAMERA);
    }
    if (constraints.audio) {
      permissions.push(RuntimePermissions.RECORD_AUDIO);
    }

    return permissions;
  },

  // Get a list of string names for devices. Ensures that none of the strings are blank
  _getList: function(aDevices, aType) {
    let defaultCount = 0;
    return aDevices.map(function(device) {
      // if this is a Camera input, convert the name to something readable
      let res = /Camera\ \d+,\ Facing (front|back)/.exec(device.name);
      if (res) {
        return Strings.browser.GetStringFromName(
          "getUserMedia." + aType + "." + res[1] + "Camera"
        );
      }

      if (device.name.startsWith("&") && device.name.endsWith(";")) {
        return Strings.browser.GetStringFromName(
          device.name.substring(1, device.name.length - 1)
        );
      }

      if (device.name.trim() == "") {
        defaultCount++;
        return Strings.browser.formatStringFromName(
          "getUserMedia." + aType + ".default",
          [defaultCount]
        );
      }
      return device.name;
    }, this);
  },

  _addDevicesToOptions: function(aDevices, aType, aOptions) {
    if (aDevices.length) {
      // Filter out empty items from the list
      let list = this._getList(aDevices, aType);

      if (list.length > 0) {
        aOptions.inputs.push({
          id: aType,
          type: "menulist",
          label: Strings.browser.GetStringFromName(
            "getUserMedia." + aType + ".prompt"
          ),
          values: list,
        });
      }
    }
  },

  showBlockMessage: function(aWindow, aDevices) {
    let microphone = false;
    let camera = false;

    for (let device of aDevices) {
      device = device.QueryInterface(Ci.nsIMediaDevice);
      if (device.type == "audioinput") {
        microphone = true;
      } else if (device.type == "videoinput") {
        camera = true;
      }
    }

    let message;
    if (microphone && !camera) {
      message = Strings.browser.GetStringFromName(
        "getUserMedia.blockedMicrophoneAccess"
      );
    } else if (camera && !microphone) {
      message = Strings.browser.GetStringFromName(
        "getUserMedia.blockedCameraAccess"
      );
    } else {
      message = Strings.browser.GetStringFromName(
        "getUserMedia.blockedCameraAndMicrophoneAccess"
      );
    }

    DoorHanger.show(aWindow, message, "webrtc-blocked");
  },

  getChromeWindow: function getChromeWindow(aWindow) {
    return aWindow.docShell.rootTreeItem.domWindow;
  },

  prompt: function prompt(
    aContentWindow,
    aCallID,
    aAudioRequested,
    aVideoRequested,
    aDevices
  ) {
    let audioDevices = [];
    let videoDevices = [];
    for (let device of aDevices) {
      device = device.QueryInterface(Ci.nsIMediaDevice);
      switch (device.type) {
        case "audioinput":
          if (aAudioRequested) {
            audioDevices.push(device);
          }
          break;
        case "videoinput":
          if (aVideoRequested) {
            videoDevices.push(device);
          }
          break;
      }
    }

    let requestType;
    if (audioDevices.length && videoDevices.length) {
      requestType = "CameraAndMicrophone";
    } else if (audioDevices.length) {
      requestType = "Microphone";
    } else if (videoDevices.length) {
      requestType = "Camera";
    } else {
      return;
    }

    let chromeWin = this.getChromeWindow(aContentWindow);
    let principal = aContentWindow.document.nodePrincipal;
    let host = principal.URI.host;
    let requestor =
      chromeWin.BrowserApp && chromeWin.BrowserApp.manifest
        ? "'" + chromeWin.BrowserApp.manifest.name + "'"
        : host;
    let message = Strings.browser.formatStringFromName(
      "getUserMedia.share" + requestType + ".message",
      [requestor]
    );

    let options = { inputs: [] };
    if (videoDevices.length > 1 || audioDevices.length > 0) {
      // videoSource is both the string used for l10n lookup and the object that will be returned
      this._addDevicesToOptions(videoDevices, "videoSource", options);
    }

    if (audioDevices.length > 1 || videoDevices.length > 0) {
      this._addDevicesToOptions(audioDevices, "audioDevice", options);
    }

    let buttons = this.getDeviceButtons(
      audioDevices,
      videoDevices,
      aCallID,
      principal
    );

    DoorHanger.show(
      aContentWindow,
      message,
      "webrtc-request",
      buttons,
      options,
      "WEBRTC"
    );
  },
};