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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/. */
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
EventEmitter: "resource://gre/modules/EventEmitter.sys.mjs",
});
/**
* The NavigationListener simply wraps a NavigationManager instance and exposes
* it with a convenient listener API, more consistent with the rest of the
* remote codebase. NavigationManager is a singleton per session so it can't
* be instanciated for each and every consumer.
*
* Example:
* ```
* const onNavigationStarted = (eventName, data = {}) => {
* const { level, message, stacktrace, timestamp } = data;
* ...
* };
*
* const listener = new NavigationListener(this.messageHandler.navigationManager);
* listener.on("navigation-started", onNavigationStarted);
* listener.startListening();
* ...
* listener.stopListening();
* ```
*
* @fires message
* The NavigationListener emits "fragment-navigated", "navigation-started",
* "navigation-stopped", and "same-document-changed" events,
* with the following object as payload:
* - {string} navigationId - The UUID for the navigation.
* - {string} navigableId - The UUID for the navigable.
* - {string} url - The target url for the navigation.
*/
export class NavigationListener {
#listening;
#navigationManager;
/**
* Create a new NavigationListener instance.
*
* @param {NavigationManager} navigationManager
* The underlying NavigationManager for this listener.
*/
constructor(navigationManager) {
lazy.EventEmitter.decorate(this);
this.#listening = false;
this.#navigationManager = navigationManager;
}
get listening() {
return this.#listening;
}
destroy() {
this.stopListening();
}
startListening() {
if (this.#listening) {
return;
}
this.#navigationManager.on("fragment-navigated", this.#forwardEvent);
this.#navigationManager.on("navigation-started", this.#forwardEvent);
this.#navigationManager.on("navigation-stopped", this.#forwardEvent);
this.#navigationManager.on("same-document-changed", this.#forwardEvent);
this.#listening = true;
}
stopListening() {
if (!this.#listening) {
return;
}
this.#navigationManager.off("fragment-navigated", this.#forwardEvent);
this.#navigationManager.off("navigation-started", this.#forwardEvent);
this.#navigationManager.off("navigation-stopped", this.#forwardEvent);
this.#navigationManager.off("same-document-changed", this.#forwardEvent);
this.#listening = false;
}
#forwardEvent = (name, data) => {
this.emit(name, data);
};
}