Source code

Revision control

Copy as Markdown

Other Tools

/* 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";
var EXPORTED_SYMBOLS = ["TranslationChild"];
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
const lazy = {};
ChromeUtils.defineModuleGetter(
lazy,
"LanguageDetector",
);
const STATE_OFFER = 0;
const STATE_TRANSLATED = 2;
const STATE_ERROR = 3;
class TranslationChild extends JSWindowActorChild {
handleEvent(aEvent) {
switch (aEvent.type) {
case "pageshow":
// We are only listening to pageshow events.
let content = this.contentWindow;
if (!content.detectedLanguage) {
return;
}
let data = {};
let trDoc = content.translationDocument;
if (trDoc) {
data.state = trDoc.translationError ? STATE_ERROR : STATE_TRANSLATED;
data.translatedFrom = trDoc.translatedFrom;
data.translatedTo = trDoc.translatedTo;
data.originalShown = trDoc.originalShown;
} else {
data.state = STATE_OFFER;
data.originalShown = true;
}
data.detectedLanguage = content.detectedLanguage;
this.sendAsyncMessage("Translation:DocumentState", data);
break;
case "load":
this.checkForTranslation();
break;
}
}
checkForTranslation() {
let url = String(this.document.location);
if (!url.startsWith("http://") && !url.startsWith("https://")) {
return;
}
let content = this.contentWindow;
if (content.detectedLanguage) {
return;
}
// Grab a 60k sample of text from the page.
let encoder = Cu.createDocumentEncoder("text/plain");
encoder.init(this.document, "text/plain", encoder.SkipInvisibleContent);
let string = encoder.encodeToStringWithMaxLength(60 * 1024);
// Language detection isn't reliable on very short strings.
if (string.length < 100) {
return;
}
lazy.LanguageDetector.detectLanguage(string).then(result => {
// Bail if we're not confident.
if (!result.confident) {
return;
}
// The window might be gone by now.
if (Cu.isDeadWrapper(content)) {
return;
}
content.detectedLanguage = result.language;
let data = {
state: STATE_OFFER,
originalShown: true,
detectedLanguage: result.language,
};
this.sendAsyncMessage("Translation:DocumentState", data);
});
}
async doTranslation(aFrom, aTo) {
var { TranslationDocument } = ChromeUtils.import(
);
// If a TranslationDocument already exists for this document, it should
// be used instead of creating a new one so that we can use the original
// content of the page for the new translation instead of the newly
// translated text.
let translationDocument =
this.contentWindow.translationDocument ||
new TranslationDocument(this.document);
let engine = Services.prefs.getCharPref("browser.translation.engine");
let importScope = ChromeUtils.import(
`resource:///modules/translation/${engine}Translator.jsm`
);
let translator = new importScope[engine + "Translator"](
translationDocument,
aFrom,
aTo
);
this.contentWindow.translationDocument = translationDocument;
translationDocument.translatedFrom = aFrom;
translationDocument.translatedTo = aTo;
translationDocument.translationError = false;
let result;
try {
let translateResult = await translator.translate();
result = {
characterCount: translateResult.characterCount,
from: aFrom,
to: aTo,
success: true,
};
translationDocument.showTranslation();
return result;
} catch (ex) {
translationDocument.translationError = true;
result = { success: false };
if (ex == "unavailable") {
result.unavailable = true;
}
}
return result;
}
receiveMessage(aMessage) {
switch (aMessage.name) {
case "Translation:TranslateDocument": {
return this.doTranslation(aMessage.data.from, aMessage.data.to);
}
case "Translation:ShowOriginal":
this.contentWindow.translationDocument.showOriginal();
break;
case "Translation:ShowTranslation":
this.contentWindow.translationDocument.showTranslation();
break;
}
return undefined;
}
}