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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 http://mozilla.org/MPL/2.0/. */
"use strict";
var EXPORTED_SYMBOLS = ["LightweightThemeChild"];
const { Services } = 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).
* The manual instantiation is necessary due to Bug 1596852.
*/
class LightweightThemeChild extends JSWindowActorChild {
constructor() {
super();
this._initted = false;
Services.cpmm.sharedData.addEventListener("change", this);
}
didDestroy() {
Services.cpmm.sharedData.removeEventListener("change", this);
}
_getChromeOuterWindowID() {
try {
// Getting the browserChild throws an exception when it is null.
let browserChild = this.docShell.browserChild;
if (browserChild) {
return browserChild.chromeOuterWindowID;
}
} catch (ex) {}
// We don't have a message manager, so presumable we're running in a sidebar
// in the parent process.
return this.contentWindow.top?.docShell?.outerWindowID;
}
/**
* Handles "change" events on the child sharedData map, and notifies
* our content page if its theme data was among the changed keys.
*/
handleEvent(event) {
switch (event.type) {
// Make sure to update the theme data on first page show.
case "pageshow":
case "DOMContentLoaded":
if (!this._initted && this._getChromeOuterWindowID()) {
this._initted = true;
this.update();
}
break;
case "change":
if (
event.changedKeys.includes(`theme/${this._getChromeOuterWindowID()}`)
) {
this.update();
}
break;
}
}
/**
* Forward the theme data to the page.
*/
update() {
const event = Cu.cloneInto(
{
detail: {
data: Services.cpmm.sharedData.get(
`theme/${this._getChromeOuterWindowID()}`
),
},
},
this.contentWindow
);
this.contentWindow.dispatchEvent(
new this.contentWindow.CustomEvent("LightweightTheme:Set", event)
);
}
}