/* 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/. */
/**
* This module provides the means to monitor and query for tab collections against open
* browser windows and allow listeners to be notified of changes to those collections.
*/
const lazy = {};
ChromeUtils.defineESModuleGetters(lazy, {
DeferredTask: "resource://gre/modules/DeferredTask.sys.mjs",
EveryWindow: "resource:///modules/EveryWindow.sys.mjs",
PrivateBrowsingUtils: "resource://gre/modules/PrivateBrowsingUtils.sys.mjs",
});
const TAB_ATTRS_TO_WATCH = Object.freeze([
"attention",
"image",
"label",
"muted",
"soundplaying",
"titlechanged",
]);
const TAB_CHANGE_EVENTS = Object.freeze([
"TabAttrModified",
"TabClose",
"TabMove",
"TabOpen",
"TabPinned",
"TabUnpinned",
]);
const TAB_RECENCY_CHANGE_EVENTS = Object.freeze([
"activate",
"sizemodechange",
"TabAttrModified",
"TabClose",
"TabOpen",
"TabPinned",
"TabUnpinned",
"TabSelect",
"TabAttrModified",
]);
// Debounce tab/tab recency changes and dispatch max once per frame at 60fps
const CHANGES_DEBOUNCE_MS = 1000 / 60;
/**
* A sort function used to order tabs by most-recently seen and active.
*/
export function lastSeenActiveSort(a, b) {
let dt = b.lastSeenActive - a.lastSeenActive;
if (dt) {
return dt;
}
// try to break a deadlock by sorting the selected tab higher
if (!(a.selected || b.selected)) {
return 0;
}
return a.selected ? -1 : 1;
}
/**
* Provides a object capable of monitoring and accessing tab collections for either
* private or non-private browser windows. As the class extends EventTarget, consumers
* should add event listeners for the change events.
*
* @param {boolean} options.usePrivateWindows
Constrain to only windows that match this privateness. Defaults to false.
* @param {Window | null} options.exclusiveWindow
* Constrain to only a specific window.
*/
class OpenTabsTarget extends EventTarget {
#changedWindowsByType = {
TabChange: new Set(),
TabRecencyChange: new Set(),
};
#sourceEventsByType = {
TabChange: new Set(),
TabRecencyChange: new Set(),
};
#dispatchChangesTask;
#started = false;
#watchedWindows = new Set();
#exclusiveWindowWeakRef = null;
usePrivateWindows = false;
constructor(options = {}) {
super();
this.usePrivateWindows = !!options.usePrivateWindows;
if (options.exclusiveWindow) {
this.exclusiveWindow = options.exclusiveWindow;
this.everyWindowCallbackId = `opentabs-${this.exclusiveWindow.windowGlobalChild.in
nerWindowId}`;
} else {
this.everyWindowCallbackId = `opentabs-${
this.usePrivateWindows ? "private" : "non-private"
}`;
}
}
get exclusiveWindow() {
return this.#exclusiveWindowWeakRef?.get();
}
set exclusiveWindow(newValue) {
if (newValue) {
this.#exclusiveWindowWeakRef = Cu.getWeakReference(newValue);
} else {
this.#exclusiveWindowWeakRef = null;
}
}
includeWindowFilter(win) {
if (this.#exclusiveWindowWeakRef) {
return win == this.exclusiveWindow;
}
return (
win.gBrowser &&
!win.closed &&
this.usePrivateWindows == lazy.PrivateBrowsingUtils.isWindowPrivate(win)
);
}
get currentWindows() {
return lazy.EveryWindow.readyWindows.filter(win =>
this.includeWindowFilter(win)
);
}
/**
* A promise that resolves to all matched windows once their delayedStartupPromise resolves
*/
get readyWindowsPromise() {
let windowList = Array.from(
Services.wm.getEnumerator("navigator:browser")
).filter(win => {
// avoid waiting for windows we definitely don't care about
if (this.#exclusiveWindowWeakRef) {
return this.exclusiveWindow == win;
}
return (
this.usePrivateWindows == lazy.PrivateBrowsingUtils.isWindowPrivate(win)
);
});
return Promise.allSettled(
windowList.map(win => win.delayedStartupPromise)
).then(() => {
// re-filter the list as properties might have changed in the interim
return windowList.filter(() => this.includeWindowFilter);
});
}
haveListenersForEvent(eventType) {
switch (eventType) {
case "TabChange":
return Services.els.hasListenersFor(this, "TabChange");
case "TabRecencyChange":
return Services.els.hasListenersFor(this, "TabRecencyChange");
default:
return false;
}
}
get haveAnyListeners() {
return (
this.haveListenersForEvent("TabChange") ||
this.haveListenersForEvent("TabRecencyChange")
);
}
/*
* @param {string} type
* Either "TabChange" or "TabRecencyChange"
* @param {Object|Function} listener
* @param {Object} [options]
*/
addEventListener(type, listener, options) {
let hadListeners = this.haveAnyListeners;
super.addEventListener(type, listener, options);
// if this is the first listener, start up all the window & tab monitoring
if (!hadListeners && this.haveAnyListeners) {
this.start();
}
}
/*
* @param {string} type
* Either "TabChange" or "TabRecencyChange"
* @param {Object|Function} listener
*/
removeEventListener(type, listener) {
let hadListeners = this.haveAnyListeners;
super.removeEventListener(type, listener);
// if this was the last listener, we can stop all the window & tab monitoring
if (hadListeners && !this.haveAnyListeners) {
this.stop();
}
}
/**
* Begin watching for tab-related events from all browser windows matching the instance's private property
*/
start() {
if (this.#started) {
return;
}
// EveryWindow will call #watchWindow for each open window once its delayedStartupPromise resolves.
lazy.EveryWindow.registerCallback(
this.everyWindowCallbackId,
win => this.#watchWindow(win),
win => this.#unwatchWindow(win)
);
this.#started = true;
}
/**
* Stop watching for tab-related events from all browser windows and clean up.
*/
stop() {
if (this.#started) {
lazy.EveryWindow.unregisterCallback(this.everyWindowCallbackId);
this.#started = false;
}
for (let changedWindows of Object.values(this.#changedWindowsByType)) {
changedWindows.clear();
}
for (let sourceEvents of Object.values(this.#sourceEventsByType)) {
sourceEvents.clear();
}
this.#watchedWindows.clear();
this.#dispatchChangesTask?.disarm();
}
/**
* Add listeners for tab-related events from the given window. The consumer's
* listeners will always be notified at least once for newly-watched window.
*/
#watchWindow(win) {
if (!this.includeWindowFilter(win)) {
return;
}
this.#watchedWindows.add(win);
const { tabContainer } = win.gBrowser;
tabContainer.addEventListener("TabAttrModified", this);
tabContainer.addEventListener("TabClose", this);
tabContainer.addEventListener("TabMove", this);
tabContainer.addEventListener("TabOpen", this);
tabContainer.addEventListener("TabPinned", this);
tabContainer.addEventListener("TabUnpinned", this);
tabContainer.addEventListener("TabSelect", this);
win.addEventListener("activate", this);
win.addEventListener("sizemodechange", this);
this.#scheduleEventDispatch("TabChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: "watchWindow",
});
this.#scheduleEventDispatch("TabRecencyChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: "watchWindow",
});
}
/**
* Remove all listeners for tab-related events from the given window.
* Consumers will always be notified at least once for unwatched window.
*/
#unwatchWindow(win) {
// We check the window is in our watchedWindows collection rather than currentWindows
// as the unwatched window may not match the criteria we used to watch it anymore,
// and we need to unhook our event listeners regardless.
if (this.#watchedWindows.has(win)) {
this.#watchedWindows.delete(win);
const { tabContainer } = win.gBrowser;
tabContainer.removeEventListener("TabAttrModified", this);
tabContainer.removeEventListener("TabClose", this);
tabContainer.removeEventListener("TabMove", this);
tabContainer.removeEventListener("TabOpen", this);
tabContainer.removeEventListener("TabPinned", this);
tabContainer.removeEventListener("TabSelect", this);
tabContainer.removeEventListener("TabUnpinned", this);
win.removeEventListener("activate", this);
win.removeEventListener("sizemodechange", this);
this.#scheduleEventDispatch("TabChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: "unwatchWindow",
});
this.#scheduleEventDispatch("TabRecencyChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: "unwatchWindow",
});
}
}
/**
* Flag the need to notify all our consumers of a change to open tabs.
* Repeated calls within approx 16ms will be consolidated
* into one event dispatch.
*/
#scheduleEventDispatch(eventType, { sourceWindowId, sourceEvent } = {}) {
if (!this.haveListenersForEvent(eventType)) {
return;
}
this.#sourceEventsByType[eventType].add(sourceEvent);
this.#changedWindowsByType[eventType].add(sourceWindowId);
// Queue up an event dispatch - we use a deferred task to make this less noisy by
// consolidating multiple change events into one.
if (!this.#dispatchChangesTask) {
this.#dispatchChangesTask = new lazy.DeferredTask(() => {
this.#dispatchChanges();
}, CHANGES_DEBOUNCE_MS);
}
this.#dispatchChangesTask.arm();
}
#dispatchChanges() {
this.#dispatchChangesTask?.disarm();
for (let [eventType, changedWindowIds] of Object.entries(
this.#changedWindowsByType
)) {
let sourceEvents = this.#sourceEventsByType[eventType];
if (this.haveListenersForEvent(eventType) && changedWindowIds.size) {
let changeEvent = new CustomEvent(eventType, {
detail: {
windowIds: [...changedWindowIds],
sourceEvents: [...sourceEvents],
},
});
this.dispatchEvent(changeEvent);
changedWindowIds.clear();
}
sourceEvents?.clear();
}
}
/*
* @param {Window} win
* @param {boolean} sortByRecency
* @returns {Array<Tab>}
* The list of visible tabs for the browser window
*/
getTabsForWindow(win, sortByRecency = false) {
if (this.currentWindows.includes(win)) {
const tabs = win.gBrowser.openTabs.filter(tab => !tab.hidden);
return sortByRecency ? tabs.toSorted(lastSeenActiveSort) : tabs;
}
return [];
}
/**
* Get an aggregated list of tabs from all the same-privateness browser windows.
*
* @returns {MozTabbrowserTab[]}
*/
getAllTabs() {
return this.currentWindows.flatMap(win => this.getTabsForWindow(win));
}
/*
* @returns {Array<Tab>}
* A by-recency-sorted, aggregated list of tabs from all the same-privateness browser windows.
*/
getRecentTabs() {
return this.getAllTabs().sort(lastSeenActiveSort);
}
handleEvent({ detail, target, type }) {
const win = target.ownerGlobal;
// NOTE: we already filtered on privateness by not listening for those events
// from private/not-private windows
if (
type == "TabAttrModified" &&
!detail.changed.some(attr => TAB_ATTRS_TO_WATCH.includes(attr))
) {
return;
}
if (TAB_RECENCY_CHANGE_EVENTS.includes(type)) {
this.#scheduleEventDispatch("TabRecencyChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: type,
});
}
if (TAB_CHANGE_EVENTS.includes(type)) {
this.#scheduleEventDispatch("TabChange", {
sourceWindowId: win.windowGlobalChild.innerWindowId,
sourceEvent: type,
});
}
}
}
const gExclusiveWindows = new (class {
perWindowInstances = new WeakMap();
constructor() {
Services.obs.addObserver(this, "domwindowclosed");
}
observe(subject) {
let win = subject;
let winTarget = this.perWindowInstances.get(win);
if (winTarget) {
winTarget.stop();
this.perWindowInstances.delete(win);
}
}
})();
/**
* Get an OpenTabsTarget instance constrained to a specific window.
*
* @param {Window} exclusiveWindow
* @returns {OpenTabsTarget}
*/
const getTabsTargetForWindow = function (exclusiveWindow) {
let instance = gExclusiveWindows.perWindowInstances.get(exclusiveWindow);
if (instance) {
return instance;
}
instance = new OpenTabsTarget({
exclusiveWindow,
});
gExclusiveWindows.perWindowInstances.set(exclusiveWindow, instance);
return instance;
};
const NonPrivateTabs = new OpenTabsTarget({
usePrivateWindows: false,
});
const PrivateTabs = new OpenTabsTarget({
usePrivateWindows: true,
});
export { NonPrivateTabs, PrivateTabs, getTabsTargetForWindow };
