editor/AsyncSpellCheckTestHelper.jsm
author Narcis Beleuzu <nbeleuzu@mozilla.com>
Fri, 15 Dec 2017 02:16:50 +0200
changeset 396515 d0d709880f192e88d1601b657cd562a6fe56d4aa
parent 353235 56bf52d4ddeb1dc7019c4f9e23961670d0a31414
child 402660 b38d59f71915f78922b46a7c7bc65a48488c45f1
permissions -rw-r--r--
Backed out 7 changesets (bug 1377007) for web platform reftests failures on CSS2/borders. r=backout Backed out changeset c30bc5d5adbc (bug 1377007) Backed out changeset 33fdf9e531e2 (bug 1377007) Backed out changeset 267abdb38036 (bug 1377007) Backed out changeset 4a452c3ac115 (bug 1377007) Backed out changeset e9310960c9e6 (bug 1377007) Backed out changeset 8e5e61dfbbaf (bug 1377007) Backed out changeset 9ac83e79e656 (bug 1377007)

/* 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/. */

this.EXPORTED_SYMBOLS = [
  "onSpellCheck",
];

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.ownerGlobal;
    editor = win.QueryInterface(Ci.nsIInterfaceRequestor).
                 getInterface(Ci.nsIWebNavigation).
                 QueryInterface(Ci.nsIInterfaceRequestor).
                 getInterface(Ci.nsIEditingSession).
                 getEditorForWindow(win);
  }
  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)
      return;
    count = 0;
    let expectedTopic = waitingForEnded ? SPELL_CHECK_ENDED_TOPIC :
                        SPELL_CHECK_STARTED_TOPIC;
    if (topic != expectedTopic)
      Cu.reportError("Expected " + expectedTopic + " but got " + topic + "!");
    waitingForEnded = !waitingForEnded;
  }

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

  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)
      return;
    timer.cancel();
    os.removeObserver(observe, SPELL_CHECK_STARTED_TOPIC);
    os.removeObserver(observe, SPELL_CHECK_ENDED_TOPIC);
    callback();
  }, 0, Ci.nsITimer.TYPE_REPEATING_SLACK);
};