gecko-dev/browser/actors/LightweightThemeChild.jsm

88 строки
2.7 KiB
JavaScript

/* 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 = ["LightweightThemeChild"];
ChromeUtils.import("resource://gre/modules/ActorChild.jsm");
ChromeUtils.import("resource://gre/modules/Services.jsm");
/**
* LightweightThemeChild forwards theme data to in-content pages.
* It is both instantiated by the traditional Actor mechanism,
* and also manually within the sidebar JS global (which has no message manager)
*/
class LightweightThemeChild extends ActorChild {
constructor(dispatcher) {
if (dispatcher.mm) {
// This is being instantiated by the Actor mechanism.
super(dispatcher);
} else {
// Manually instantiated by the sidebar.
let fakeDispatcher = {
mm: dispatcher,
window: dispatcher.content,
addEventListener: dispatcher.content.addEventListener,
};
super(fakeDispatcher);
}
this.init();
}
/**
* Initializes the actor for the current page, sending it any existing
* theme data, and adding shared data change listeners so it can
* notify the page of future updates.
*
* This is called when the actor is constructed, and any time
* ActorManagerChild receives a pageshow event for the page we're
* attached to.
*/
init() {
Services.cpmm.sharedData.addEventListener("change", this);
this.update(this.mm.chromeOuterWindowID, this.content);
}
/**
* Cleans up any global listeners registered by the actor.
*
* This is called by ActorManagerChild any time it receives a pagehide
* event for the page we're attached to.
*/
cleanup() {
super.cleanup();
Services.cpmm.sharedData.removeEventListener("change", this);
}
/**
* Handles "change" events on the child sharedData map, and notifies
* our content page if its theme data was among the changed keys.
*/
handleEvent(event) {
if (event.type === "change") {
if (event.changedKeys.includes(`theme/${this.mm.chromeOuterWindowID}`)) {
this.update(this.mm.chromeOuterWindowID, this.content);
}
}
}
/**
* Forward the theme data to the page.
* @param {Object} outerWindowID The outerWindowID the parent process window has.
* @param {Object} content The receiving global
*/
update(outerWindowID, content) {
const event = Cu.cloneInto({
detail: {
data: Services.cpmm.sharedData.get(`theme/${outerWindowID}`),
},
}, content);
content.dispatchEvent(new content.CustomEvent("LightweightTheme:Set",
event));
}
}