gecko-dev/toolkit/actors/AutoScrollParent.jsm

54 строки
2.0 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";
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
var EXPORTED_SYMBOLS = ["AutoScrollParent"];
class AutoScrollParent extends JSWindowActorParent {
receiveMessage(msg) {
let browser = this.manager.browsingContext.top.embedderElement;
if (!browser) {
return null;
}
// If another tab is activated, we shouldn't start autoscroll requested
// for the previous active window if and only if the browser is a remote
// browser. This is required for web apps which don't prevent default of
// middle click after opening a new window. If the active tab is our
// documents like about:*, we don't need this check since our documents
// should do it correctly.
const requestedInForegroundTab = browser.isRemoteBrowser
? Services.focus.focusedElement == browser
: true;
let data = msg.data;
switch (msg.name) {
case "Autoscroll:Start":
// Don't start autoscroll if the tab has already been a background tab.
if (!requestedInForegroundTab) {
return Promise.resolve({ autoscrollEnabled: false, usingAPZ: false });
}
return Promise.resolve(browser.startScroll(data));
case "Autoscroll:MaybeStartInParent":
// Don't start autoscroll if the tab has already been a background tab.
if (!requestedInForegroundTab) {
return Promise.resolve({ autoscrollEnabled: false, usingAPZ: false });
}
let parent = this.browsingContext.parent;
if (parent) {
let actor = parent.currentWindowGlobal.getActor("AutoScroll");
actor.sendAsyncMessage("Autoscroll:MaybeStart", data);
}
break;
case "Autoscroll:Cancel":
browser.cancelScroll();
break;
}
return null;
}
}