gecko-dev/remote/domains/Domain.jsm
2019-07-12 08:30:03 +00:00

76 lines
2.0 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 = ["Domain"];
class Domain {
constructor(session) {
this.session = session;
this.name = this.constructor.name;
this.eventListeners_ = new Set();
this._requestCounter = 0;
}
destructor() {}
emit(eventName, params = {}) {
for (const listener of this.eventListeners_) {
try {
if (isEventHandler(listener)) {
listener.onEvent(eventName, params);
} else {
listener.call(this, eventName, params);
}
} catch (e) {
Cu.reportError(e);
}
}
}
/**
* Execute the provided method in the child domain that has the same domain
* name. eg. calling this.executeInChild from domains/parent/Input.jsm will
* attempt to execute the method in domains/content/Input.jsm.
*
* This can only be called from parent domains managed by a TabSession.
*
* @param {String} method
* Name of the method to call on the child domain.
* @param {Object} params
* Optional parameters. Must be serializable.
*/
executeInChild(method, params) {
if (!this.session.executeInChild) {
throw new Error(
"executeInChild can only be used in Domains managed by a TabSession"
);
}
this._requestCounter++;
const id = this.name + "-" + this._requestCounter;
return this.session.executeInChild(id, this.name, method, params);
}
addEventListener(listener) {
if (typeof listener != "function" && !isEventHandler(listener)) {
throw new TypeError();
}
this.eventListeners_.add(listener);
}
// static
static implements(command) {
return command && typeof this.prototype[command] == "function";
}
}
function isEventHandler(listener) {
return (
listener && "onEvent" in listener && typeof listener.onEvent == "function"
);
}