pdf.js/extensions/firefox/content/PdfjsChromeUtils.jsm

/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/* globals Components, Services, XPCOMUtils */

"use strict";

var EXPORTED_SYMBOLS = ["PdfjsChromeUtils"];

const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const Cu = Components.utils;

const PREF_PREFIX = "PDFJSSCRIPT_PREF_PREFIX";
const PDF_CONTENT_TYPE = "application/pdf";

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

var Svc = {};
XPCOMUtils.defineLazyServiceGetter(Svc, "mime",
                                   "@mozilla.org/mime;1",
                                   "nsIMIMEService");

var DEFAULT_PREFERENCES =
//#include ../../../web/default_preferences.json
//#if false
  "end of DEFAULT_PREFERENCES";
//#endif

var PdfjsChromeUtils = {
  // For security purposes when running remote, we restrict preferences
  // content can access.
  _allowedPrefNames: Object.keys(DEFAULT_PREFERENCES),
  _ppmm: null,
  _mmg: null,

  /*
   * Public API
   */

  init() {
    this._browsers = new WeakSet();
    if (!this._ppmm) {
      // global parent process message manager (PPMM)
      this._ppmm = Cc["@mozilla.org/parentprocessmessagemanager;1"].
        getService(Ci.nsIMessageBroadcaster);
      this._ppmm.addMessageListener("PDFJS:Parent:clearUserPref", this);
      this._ppmm.addMessageListener("PDFJS:Parent:setIntPref", this);
      this._ppmm.addMessageListener("PDFJS:Parent:setBoolPref", this);
      this._ppmm.addMessageListener("PDFJS:Parent:setCharPref", this);
      this._ppmm.addMessageListener("PDFJS:Parent:setStringPref", this);
      this._ppmm.addMessageListener("PDFJS:Parent:isDefaultHandlerApp", this);

      // global dom message manager (MMg)
      this._mmg = Cc["@mozilla.org/globalmessagemanager;1"].
        getService(Ci.nsIMessageListenerManager);
      this._mmg.addMessageListener("PDFJS:Parent:displayWarning", this);

      this._mmg.addMessageListener("PDFJS:Parent:addEventListener", this);
      this._mmg.addMessageListener("PDFJS:Parent:removeEventListener", this);
      this._mmg.addMessageListener("PDFJS:Parent:updateControlState", this);

      // observer to handle shutdown
      Services.obs.addObserver(this, "quit-application", false);
    }
  },

  uninit() {
    if (this._ppmm) {
      this._ppmm.removeMessageListener("PDFJS:Parent:clearUserPref", this);
      this._ppmm.removeMessageListener("PDFJS:Parent:setIntPref", this);
      this._ppmm.removeMessageListener("PDFJS:Parent:setBoolPref", this);
      this._ppmm.removeMessageListener("PDFJS:Parent:setCharPref", this);
      this._ppmm.removeMessageListener("PDFJS:Parent:setStringPref", this);
      this._ppmm.removeMessageListener("PDFJS:Parent:isDefaultHandlerApp",
                                       this);

      this._mmg.removeMessageListener("PDFJS:Parent:displayWarning", this);

      this._mmg.removeMessageListener("PDFJS:Parent:addEventListener", this);
      this._mmg.removeMessageListener("PDFJS:Parent:removeEventListener", this);
      this._mmg.removeMessageListener("PDFJS:Parent:updateControlState", this);

      Services.obs.removeObserver(this, "quit-application");

      this._mmg = null;
      this._ppmm = null;
    }
  },

  /*
   * Called by the main module when preference changes are picked up
   * in the parent process. Observers don't propagate so we need to
   * instruct the child to refresh its configuration and (possibly)
   * the module's registration.
   */
  notifyChildOfSettingsChange() {
    if (Services.appinfo.processType ===
        Services.appinfo.PROCESS_TYPE_DEFAULT && this._ppmm) {
      // XXX kinda bad, we want to get the parent process mm associated
      // with the content process. _ppmm is currently the global process
      // manager, which means this is going to fire to every child process
      // we have open. Unfortunately I can't find a way to get at that
      // process specific mm from js.
      this._ppmm.broadcastAsyncMessage("PDFJS:Child:refreshSettings", {});
    }
  },

  /*
   * Events
   */

  observe(aSubject, aTopic, aData) {
    if (aTopic === "quit-application") {
      this.uninit();
    }
  },

  receiveMessage(aMsg) {
    switch (aMsg.name) {
      case "PDFJS:Parent:clearUserPref":
        this._clearUserPref(aMsg.data.name);
        break;
      case "PDFJS:Parent:setIntPref":
        this._setIntPref(aMsg.data.name, aMsg.data.value);
        break;
      case "PDFJS:Parent:setBoolPref":
        this._setBoolPref(aMsg.data.name, aMsg.data.value);
        break;
      case "PDFJS:Parent:setCharPref":
        this._setCharPref(aMsg.data.name, aMsg.data.value);
        break;
      case "PDFJS:Parent:setStringPref":
        this._setStringPref(aMsg.data.name, aMsg.data.value);
        break;
      case "PDFJS:Parent:isDefaultHandlerApp":
        return this.isDefaultHandlerApp();
      case "PDFJS:Parent:displayWarning":
        this._displayWarning(aMsg);
        break;

      case "PDFJS:Parent:updateControlState":
        return this._updateControlState(aMsg);
      case "PDFJS:Parent:addEventListener":
        return this._addEventListener(aMsg);
      case "PDFJS:Parent:removeEventListener":
        return this._removeEventListener(aMsg);
    }
    return undefined;
  },

  /*
   * Internal
   */

  _findbarFromMessage(aMsg) {
    let browser = aMsg.target;
    let tabbrowser = browser.getTabBrowser();
    let tab = tabbrowser.getTabForBrowser(browser);
    return tabbrowser.getFindBar(tab);
  },

  _updateControlState(aMsg) {
    let data = aMsg.data;
    this._findbarFromMessage(aMsg)
        .updateControlState(data.result, data.findPrevious);
  },

  handleEvent(aEvent) {
    // To avoid forwarding the message as a CPOW, create a structured cloneable
    // version of the event for both performance, and ease of usage, reasons.
    let type = aEvent.type;
    let detail = {
      query: aEvent.detail.query,
      caseSensitive: aEvent.detail.caseSensitive,
      highlightAll: aEvent.detail.highlightAll,
      findPrevious: aEvent.detail.findPrevious
    };

    let browser = aEvent.currentTarget.browser;
    if (!this._browsers.has(browser)) {
      throw new Error("FindEventManager was not bound " +
                      "for the current browser.");
    }
    // Only forward the events if the current browser is a registered browser.
    let mm = browser.messageManager;
    mm.sendAsyncMessage("PDFJS:Child:handleEvent", { type, detail, });
    aEvent.preventDefault();
  },

  _types: ["find",
           "findagain",
           "findhighlightallchange",
           "findcasesensitivitychange"],

  _addEventListener(aMsg) {
    let browser = aMsg.target;
    if (this._browsers.has(browser)) {
      throw new Error("FindEventManager was bound 2nd time " +
                      "without unbinding it first.");
    }

    // Since this jsm is global, we need to store all the browsers
    // we have to forward the messages for.
    this._browsers.add(browser);

    // And we need to start listening to find events.
    for (var i = 0; i < this._types.length; i++) {
      var type = this._types[i];
      this._findbarFromMessage(aMsg)
          .addEventListener(type, this, true);
    }
  },

  _removeEventListener(aMsg) {
    let browser = aMsg.target;
    if (!this._browsers.has(browser)) {
      throw new Error("FindEventManager was unbound without binding it first.");
    }

    this._browsers.delete(browser);

    // No reason to listen to find events any longer.
    for (var i = 0; i < this._types.length; i++) {
      var type = this._types[i];
      this._findbarFromMessage(aMsg)
          .removeEventListener(type, this, true);
    }
  },

  _ensurePreferenceAllowed(aPrefName) {
    let unPrefixedName = aPrefName.split(PREF_PREFIX + ".");
    if (unPrefixedName[0] !== "" ||
        this._allowedPrefNames.indexOf(unPrefixedName[1]) === -1) {
      let msg = "\"" + aPrefName + "\" " +
                "can't be accessed from content. See PdfjsChromeUtils.";
      throw new Error(msg);
    }
  },

  _clearUserPref(aPrefName) {
    this._ensurePreferenceAllowed(aPrefName);
    Services.prefs.clearUserPref(aPrefName);
  },

  _setIntPref(aPrefName, aPrefValue) {
    this._ensurePreferenceAllowed(aPrefName);
    Services.prefs.setIntPref(aPrefName, aPrefValue);
  },

  _setBoolPref(aPrefName, aPrefValue) {
    this._ensurePreferenceAllowed(aPrefName);
    Services.prefs.setBoolPref(aPrefName, aPrefValue);
  },

  _setCharPref(aPrefName, aPrefValue) {
    this._ensurePreferenceAllowed(aPrefName);
    Services.prefs.setCharPref(aPrefName, aPrefValue);
  },

  _setStringPref(aPrefName, aPrefValue) {
    this._ensurePreferenceAllowed(aPrefName);
    let str = Cc["@mozilla.org/supports-string;1"]
                .createInstance(Ci.nsISupportsString);
    str.data = aPrefValue;
    Services.prefs.setComplexValue(aPrefName, Ci.nsISupportsString, str);
  },

  /*
   * Svc.mime doesn't have profile information in the child, so
   * we bounce this pdfjs enabled configuration check over to the
   * parent.
   */
  isDefaultHandlerApp() {
    var handlerInfo = Svc.mime.getFromTypeAndExtension(PDF_CONTENT_TYPE, "pdf");
    return (!handlerInfo.alwaysAskBeforeHandling &&
            handlerInfo.preferredAction === Ci.nsIHandlerInfo.handleInternally);
  },

  /*
   * Display a notification warning when the renderer isn't sure
   * a pdf displayed correctly.
   */
  _displayWarning(aMsg) {
    let data = aMsg.data;
    let browser = aMsg.target;

    let tabbrowser = browser.getTabBrowser();
    let notificationBox = tabbrowser.getNotificationBox(browser);

    // Flag so we don't send the message twice, since if the user clicks
    // "open with different viewer" both the button callback and
    // eventCallback will be called.
    let messageSent = false;
    function sendMessage(download) {
      let mm = browser.messageManager;
      mm.sendAsyncMessage("PDFJS:Child:fallbackDownload", { download, });
    }
    let buttons = [{
      label: data.label,
      accessKey: data.accessKey,
      callback() {
        messageSent = true;
        sendMessage(true);
      }
    }];
    notificationBox.appendNotification(data.message, "pdfjs-fallback", null,
                                       notificationBox.PRIORITY_INFO_LOW,
                                       buttons,
                                       function eventsCallback(eventType) {
      // Currently there is only one event "removed" but if there are any other
      // added in the future we still only care about removed at the moment.
      if (eventType !== "removed") {
        return;
      }
      // Don't send a response again if we already responded when the button was
      // clicked.
      if (messageSent) {
        return;
      }
      sendMessage(false);
    });
  }
};