You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

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/* 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 */
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[";1"].
os.addObserver(observe, SPELL_CHECK_STARTED_TOPIC, false);
os.addObserver(observe, SPELL_CHECK_ENDED_TOPIC, false);
let timer = Cc[";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);