gecko-dev/browser/actors/AboutReaderChild.jsm

153 строки
5.3 KiB
JavaScript

/* vim: set ts=2 sw=2 sts=2 et tw=80: */
/* 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 = ["AboutReaderChild"];
ChromeUtils.import("resource://gre/modules/ActorChild.jsm");
ChromeUtils.defineModuleGetter(this, "AboutReader",
"resource://gre/modules/AboutReader.jsm");
ChromeUtils.defineModuleGetter(this, "ReaderMode",
"resource://gre/modules/ReaderMode.jsm");
ChromeUtils.defineModuleGetter(this, "Readerable",
"resource://gre/modules/Readerable.jsm");
class AboutReaderChild extends ActorChild {
constructor(dispatcher) {
super(dispatcher);
this._articlePromise = null;
this._isLeavingReaderableReaderMode = false;
}
receiveMessage(message) {
switch (message.name) {
case "Reader:ToggleReaderMode":
if (!this.isAboutReader) {
this._articlePromise = ReaderMode.parseDocument(this.content.document).catch(Cu.reportError);
ReaderMode.enterReaderMode(this.mm.docShell, this.content);
} else {
this._isLeavingReaderableReaderMode = this.isReaderableAboutReader;
ReaderMode.leaveReaderMode(this.mm.docShell, this.content);
}
break;
case "Reader:PushState":
this.updateReaderButton(!!(message.data && message.data.isArticle));
break;
}
}
get isAboutReader() {
if (!this.content) {
return false;
}
return this.content.document.documentURI.startsWith("about:reader");
}
get isReaderableAboutReader() {
return this.isAboutReader &&
!this.content.document.documentElement.dataset.isError;
}
handleEvent(aEvent) {
if (aEvent.originalTarget.defaultView != this.content) {
return;
}
switch (aEvent.type) {
case "AboutReaderContentLoaded":
if (!this.isAboutReader) {
return;
}
if (this.content.document.body) {
// Update the toolbar icon to show the "reader active" icon.
this.mm.sendAsyncMessage("Reader:UpdateReaderButton");
new AboutReader(this.mm, this.content, this._articlePromise);
this._articlePromise = null;
}
break;
case "pagehide":
this.cancelPotentialPendingReadabilityCheck();
// this._isLeavingReaderableReaderMode is used here to keep the Reader Mode icon
// visible in the location bar when transitioning from reader-mode page
// back to the readable source page.
this.mm.sendAsyncMessage("Reader:UpdateReaderButton", { isArticle: this._isLeavingReaderableReaderMode });
if (this._isLeavingReaderableReaderMode) {
this._isLeavingReaderableReaderMode = false;
}
break;
case "pageshow":
// If a page is loaded from the bfcache, we won't get a "DOMContentLoaded"
// event, so we need to rely on "pageshow" in this case.
if (aEvent.persisted) {
this.updateReaderButton();
}
break;
case "DOMContentLoaded":
this.updateReaderButton();
break;
}
}
/**
* NB: this function will update the state of the reader button asynchronously
* after the next mozAfterPaint call (assuming reader mode is enabled and
* this is a suitable document). Calling it on things which won't be
* painted is not going to work.
*/
updateReaderButton(forceNonArticle) {
if (!Readerable.isEnabledForParseOnLoad || this.isAboutReader ||
!this.content || !(this.content.document instanceof this.content.HTMLDocument) ||
this.content.document.mozSyntheticDocument) {
return;
}
this.scheduleReadabilityCheckPostPaint(forceNonArticle);
}
cancelPotentialPendingReadabilityCheck() {
if (this._pendingReadabilityCheck) {
this.mm.removeEventListener("MozAfterPaint", this._pendingReadabilityCheck);
delete this._pendingReadabilityCheck;
}
}
scheduleReadabilityCheckPostPaint(forceNonArticle) {
if (this._pendingReadabilityCheck) {
// We need to stop this check before we re-add one because we don't know
// if forceNonArticle was true or false last time.
this.cancelPotentialPendingReadabilityCheck();
}
this._pendingReadabilityCheck = this.onPaintWhenWaitedFor.bind(this, forceNonArticle);
this.mm.addEventListener("MozAfterPaint", this._pendingReadabilityCheck);
}
onPaintWhenWaitedFor(forceNonArticle, event) {
// In non-e10s, we'll get called for paints other than ours, and so it's
// possible that this page hasn't been laid out yet, in which case we
// should wait until we get an event that does relate to our layout. We
// determine whether any of our this.content got painted by checking if there
// are any painted rects.
if (!event.clientRects.length) {
return;
}
this.cancelPotentialPendingReadabilityCheck();
// Only send updates when there are articles; there's no point updating with
// |false| all the time.
if (Readerable.isProbablyReaderable(this.content.document)) {
this.mm.sendAsyncMessage("Reader:UpdateReaderButton", { isArticle: true });
} else if (forceNonArticle) {
this.mm.sendAsyncMessage("Reader:UpdateReaderButton", { isArticle: false });
}
}
}