gecko-dev/b2g/components/PresentationRequestUIGlue.js

/* 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"

function debug(aMsg) {
  //dump("-*- PresentationRequestUIGlue: " + aMsg + "\n");
}

const { interfaces: Ci, utils: Cu, classes: Cc } = Components;

Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");

XPCOMUtils.defineLazyModuleGetter(this, "SystemAppProxy",
                                  "resource://gre/modules/SystemAppProxy.jsm");

function PresentationRequestUIGlue() {
  // This is to store the session ID / resolver binding.
  // An example of the object literal is shown below:
  //
  // {
  //   "sessionId1" : resolver1,
  //   ...
  // }
  this._resolvers = {};

  // Listen to the result for the opened iframe from front-end.
  SystemAppProxy.addEventListener("mozPresentationContentEvent", aEvent => {
    let detail = aEvent.detail;

    switch (detail.type) {
      case "presentation-receiver-launched": {
        let sessionId = detail.id;
        let resolver = this._resolvers[sessionId];
        if (!resolver) {
          debug("No correspondent resolver for session ID: " + sessionId);
          return;
        }

        delete this._resolvers[sessionId];
        resolver.resolve(detail.frame);
        break;
      }
      case "presentation-receiver-permission-denied": {
        let sessionId = detail.id;
        let resolver = this._resolvers[sessionId];
        if (!resolver) {
          debug("No correspondent resolver for session ID: " + sessionId);
          return;
        }

        delete this._resolvers[sessionId];
        resolver.reject();
        break;
      }
      default:
        return;
      }
  });
}

PresentationRequestUIGlue.prototype = {

  sendRequest: function(aUrl, aSessionId) {
    return new Promise(function(aResolve, aReject) {
      this._resolvers[aSessionId] = {
        resolve: aResolve,
        reject: aReject,
      };

      SystemAppProxy._sendCustomEvent("mozPresentationChromeEvent",
                                      { type: "presentation-launch-receiver",
                                        url: aUrl,
                                        id: aSessionId });
    }.bind(this));
  },

  classID: Components.ID("{ccc8a839-0b64-422b-8a60-fb2af0e376d0}"),

  QueryInterface: XPCOMUtils.generateQI([Ci.nsIPresentationRequestUIGlue])
};

this.NSGetFactory = XPCOMUtils.generateNSGetFactory([PresentationRequestUIGlue]);