author Michael Comella <michael.l.comella@gmail.com>
Wed, 22 Apr 2015 16:45:23 -0700
changeset 272491 501e46e3e348fdf8e503f330d40d538456d10544
parent 145664 eac7a8c8d5d42d0ca047102422e13a9bb4fec50e
child 378071 25c0a38d2d7ed50ed3c1d419f70c01595c481ae7
permissions -rw-r--r--
Bug 1137483 - Set content description of SearchEngineBar items. r=liuche I tested with Talkback to ensure only the outer container of each search engine favicon is selected.

/* 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/. */


const SPELL_CHECK_ENDED_TOPIC = "inlineSpellChecker-spellCheck-ended";
const SPELL_CHECK_STARTED_TOPIC = "inlineSpellChecker-spellCheck-started";

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

 * Waits until spell checking has stopped on the given element.
 * When a spell check is pending, this waits indefinitely until the spell check
 * ends.  When a spell check is not pending, it waits a small number of turns of
 * the event loop: if a spell check begins, it resumes waiting indefinitely for
 * the end, and otherwise it stops waiting and calls the callback.
 * This this can therefore trap spell checks that have not started at the time
 * of calling, spell checks that have already started, multiple consecutive
 * spell checks, and the absence of spell checks altogether.
 * @param editableElement  The element being spell checked.
 * @param callback         Called when spell check has completed or enough turns
 *                         of the event loop have passed to determine it has not
 *                         started.
function onSpellCheck(editableElement, callback) {
  let editor = editableElement.editor;
  if (!editor) {
    let win = editableElement.ownerDocument.defaultView;
    editor = win.QueryInterface(Ci.nsIInterfaceRequestor).
  if (!editor)
    throw new Error("Unable to find editor for element " + editableElement);

  try {
    // False is important here.  Pass false so that the inline spell checker
    // isn't created if it doesn't already exist.
    var isc = editor.getInlineSpellChecker(false);
  catch (err) {
    // getInlineSpellChecker throws if spell checking is not enabled instead of
    // just returning null, which seems kind of lame.  (Spell checking is not
    // enabled on Android.)  The point here is only to determine whether spell
    // check is pending, and if getInlineSpellChecker throws, then it's not
    // pending.
  let waitingForEnded = isc && isc.spellCheckPending;
  let count = 0;

  function observe(subj, topic, data) {
    if (subj != editor)
    count = 0;
    let expectedTopic = waitingForEnded ? SPELL_CHECK_ENDED_TOPIC :
    if (topic != expectedTopic)
      Cu.reportError("Expected " + expectedTopic + " but got " + topic + "!");
    waitingForEnded = !waitingForEnded;

  let os = Cc["@mozilla.org/observer-service;1"].
  os.addObserver(observe, SPELL_CHECK_STARTED_TOPIC, false);
  os.addObserver(observe, SPELL_CHECK_ENDED_TOPIC, false);

  let timer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
  timer.init(function tick() {
    // Wait an arbitrarily large number -- 50 -- turns of the event loop before
    // declaring that no spell checks will start.
    if (waitingForEnded || ++count < 50)
    os.removeObserver(observe, SPELL_CHECK_STARTED_TOPIC);
    os.removeObserver(observe, SPELL_CHECK_ENDED_TOPIC);
  }, 0, Ci.nsITimer.TYPE_REPEATING_SLACK);