gecko-dev/toolkit/actors/PictureInPictureChild.jsm

796 строки
28 KiB
JavaScript

/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* 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 = ["PictureInPictureChild", "PictureInPictureToggleChild"];
const {ActorChild} = ChromeUtils.import("resource://gre/modules/ActorChild.jsm");
const {XPCOMUtils} = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
ChromeUtils.defineModuleGetter(this, "DeferredTask",
"resource://gre/modules/DeferredTask.jsm");
ChromeUtils.defineModuleGetter(this, "Services",
"resource://gre/modules/Services.jsm");
XPCOMUtils.defineLazyGlobalGetters(this, ["InspectorUtils"]);
const TOGGLE_ENABLED_PREF =
"media.videocontrols.picture-in-picture.video-toggle.enabled";
const TOGGLE_TESTING_PREF =
"media.videocontrols.picture-in-picture.video-toggle.testing";
const MOUSEMOVE_PROCESSING_DELAY_MS = 50;
// A weak reference to the most recent <video> in this content
// process that is being viewed in Picture-in-Picture.
var gWeakVideo = null;
// A weak reference to the content window of the most recent
// Picture-in-Picture window for this content process.
var gWeakPlayerContent = null;
// To make it easier to write tests, we have a process-global
// WeakSet of all <video> elements that are being tracked for
// mouseover
var gWeakIntersectingVideosForTesting = new WeakSet();
/**
* The PictureInPictureToggleChild is responsible for displaying the overlaid
* Picture-in-Picture toggle over top of <video> elements that the mouse is
* hovering.
*/
class PictureInPictureToggleChild extends ActorChild {
constructor(dispatcher) {
super(dispatcher);
// We need to maintain some state about various things related to the
// Picture-in-Picture toggles - however, for now, the same
// PictureInPictureToggleChild might be re-used for different documents.
// We keep the state stashed inside of this WeakMap, keyed on the document
// itself.
this.weakDocStates = new WeakMap();
this.toggleEnabled = Services.prefs.getBoolPref(TOGGLE_ENABLED_PREF);
this.toggleTesting = Services.prefs.getBoolPref(TOGGLE_TESTING_PREF, false);
}
/**
* Returns the state for the current document referred to via
* this.content.document. If no such state exists, creates it, stores it
* and returns it.
*/
get docState() {
let state = this.weakDocStates.get(this.content.document);
if (!state) {
state = {
// A reference to the IntersectionObserver that's monitoring for videos
// to become visible.
intersectionObserver: null,
// A WeakSet of videos that are supposedly visible, according to the
// IntersectionObserver.
weakVisibleVideos: new WeakSet(),
// The number of videos that are supposedly visible, according to the
// IntersectionObserver
visibleVideosCount: 0,
// The DeferredTask that we'll arm every time a mousemove event occurs
// on a page where we have one or more visible videos.
mousemoveDeferredTask: null,
// A weak reference to the last video we displayed the toggle over.
weakOverVideo: null,
// True if the user is in the midst of clicking the toggle.
isClickingToggle: false,
// Set to the original target element on pointerdown if the user is clicking
// the toggle - this way, we can determine if a "click" event will need to be
// suppressed ("click" events don't fire if a "mouseup" occurs on a different
// element from the "pointerdown" / "mousedown" event).
clickedElement: null,
};
this.weakDocStates.set(this.content.document, state);
}
return state;
}
handleEvent(event) {
if (!event.isTrusted) {
// We don't care about synthesized events that might be coming from
// content JS.
return;
}
switch (event.type) {
case "canplay": {
if (this.toggleEnabled &&
event.target instanceof this.content.HTMLVideoElement &&
!event.target.controls &&
event.target.ownerDocument == this.content.document) {
this.registerVideo(event.target);
}
break;
}
case "mousedown":
case "pointerup":
case "mouseup":
case "click": {
this.onMouseButtonEvent(event);
break;
}
case "pointerdown": {
this.onPointerDown(event);
break;
}
case "mousemove": {
this.onMouseMove(event);
break;
}
case "pagehide": {
if (event.target.top == event.target) {
this.removeMouseButtonListeners();
}
break;
}
}
}
/**
* Adds a <video> to the IntersectionObserver so that we know when it becomes
* visible.
*
* @param {Element} video The <video> element to register.
*/
registerVideo(video) {
let state = this.docState;
if (!state.intersectionObserver) {
let fn = this.onIntersection.bind(this);
state.intersectionObserver = new this.content.IntersectionObserver(fn, {
threshold: [0.0, 0.5],
});
}
state.intersectionObserver.observe(video);
}
/**
* Called by the IntersectionObserver callback once a video becomes visible.
* This adds some fine-grained checking to ensure that a sufficient amount of
* the video is visible before we consider showing the toggles on it. For now,
* that means that the entirety of the video must be in the viewport.
*
* @param {IntersectionEntry} intersectionEntry An IntersectionEntry passed to
* the IntersectionObserver callback.
* @return bool Whether or not we should start tracking mousemove events for
* this registered video.
*/
worthTracking(intersectionEntry) {
return intersectionEntry.isIntersecting;
}
/**
* Called by the IntersectionObserver once a video crosses one of the
* thresholds dictated by the IntersectionObserver configuration.
*
* @param {Array<IntersectionEntry>} A collection of one or more
* IntersectionEntry's for <video> elements that might have entered or exited
* the viewport.
*/
onIntersection(entries) {
// The IntersectionObserver will also fire when a previously intersecting
// element is removed from the DOM. We know, however, that the node is
// still alive and referrable from the WeakSet because the
// IntersectionObserverEntry holds a strong reference to the video.
let state = this.docState;
let oldVisibleVideosCount = state.visibleVideosCount;
for (let entry of entries) {
let video = entry.target;
if (this.worthTracking(entry)) {
if (!state.weakVisibleVideos.has(video)) {
state.weakVisibleVideos.add(video);
state.visibleVideosCount++;
if (this.toggleTesting) {
gWeakIntersectingVideosForTesting.add(video);
}
}
} else if (state.weakVisibleVideos.has(video)) {
state.weakVisibleVideos.delete(video);
state.visibleVideosCount--;
if (this.toggleTesting) {
gWeakIntersectingVideosForTesting.delete(video);
}
}
}
// For testing, especially in debug or asan builds, we might not
// run this idle callback within an acceptable time. While we're
// testing, we'll bypass the idle callback performance optimization
// and run our callbacks as soon as possible during the next idle
// period.
if (!oldVisibleVideosCount && state.visibleVideosCount) {
if (this.toggleTesting) {
this.beginTrackingMouseOverVideos();
} else {
this.content.requestIdleCallback(() => {
this.beginTrackingMouseOverVideos();
});
}
} else if (oldVisibleVideosCount && !state.visibleVideosCount) {
if (this.toggleTesting) {
this.stopTrackingMouseOverVideos();
} else {
this.content.requestIdleCallback(() => {
this.stopTrackingMouseOverVideos();
});
}
}
}
addMouseButtonListeners() {
// We want to try to cancel the mouse events from continuing
// on into content if the user has clicked on the toggle, so
// we don't use the mozSystemGroup here, and add the listener
// to the parent target of the window, which in this case,
// is the windowRoot. Since this event listener is attached to
// part of the outer window, we need to also remove it in a
// pagehide event listener in the event that the page unloads
// before stopTrackingMouseOverVideos fires.
this.content.windowRoot.addEventListener("pointerdown", this,
{ capture: true });
this.content.windowRoot.addEventListener("mousedown", this,
{ capture: true });
this.content.windowRoot.addEventListener("mouseup", this,
{ capture: true });
this.content.windowRoot.addEventListener("pointerup", this,
{ capture: true });
this.content.windowRoot.addEventListener("click", this,
{ capture: true });
}
removeMouseButtonListeners() {
this.content.windowRoot.removeEventListener("pointerdown", this,
{ capture: true });
this.content.windowRoot.removeEventListener("mousedown", this,
{ capture: true });
this.content.windowRoot.removeEventListener("mouseup", this,
{ capture: true });
this.content.windowRoot.removeEventListener("pointerup", this,
{ capture: true });
this.content.windowRoot.removeEventListener("click", this,
{ capture: true });
}
/**
* One of the challenges of displaying this toggle is that many sites put
* things over top of <video> elements, like custom controls, or images, or
* all manner of things that might intercept mouseevents that would normally
* fire directly on the <video>. In order to properly detect when the mouse
* is over top of one of the <video> elements in this situation, we currently
* add a mousemove event handler to the entire document, and stash the most
* recent mousemove that fires. At periodic intervals, that stashed mousemove
* event is checked to see if it's hovering over one of our registered
* <video> elements.
*
* This sort of thing will not be necessary once bug 1539652 is fixed.
*/
beginTrackingMouseOverVideos() {
let state = this.docState;
if (!state.mousemoveDeferredTask) {
state.mousemoveDeferredTask = new DeferredTask(() => {
this.checkLastMouseMove();
}, MOUSEMOVE_PROCESSING_DELAY_MS);
}
this.content.document.addEventListener("mousemove", this,
{ mozSystemGroup: true, capture: true });
this.addMouseButtonListeners();
}
/**
* If we no longer have any interesting videos in the viewport, we deregister
* the mousemove and click listeners, and also remove any toggles that might
* be on the page still.
*/
stopTrackingMouseOverVideos() {
let state = this.docState;
state.mousemoveDeferredTask.disarm();
this.content.document.removeEventListener("mousemove", this,
{ mozSystemGroup: true, capture: true });
this.removeMouseButtonListeners();
let oldOverVideo = state.weakOverVideo && state.weakOverVideo.get();
if (oldOverVideo) {
this.onMouseLeaveVideo(oldOverVideo);
}
}
/**
* If we're tracking <video> elements, this pointerdown event handler is run anytime
* a pointerdown occurs on the document. This function is responsible for checking
* if the user clicked on the Picture-in-Picture toggle. It does this by first
* checking if the video is visible beneath the point that was clicked. Then
* it tests whether or not the pointerdown occurred within the rectangle of the
* toggle. If so, the event's propagation is stopped, and Picture-in-Picture is
* triggered.
*
* @param {Event} event The mousemove event.
*/
onPointerDown(event) {
let state = this.docState;
let video = state.weakOverVideo && state.weakOverVideo.get();
if (!video) {
return;
}
let shadowRoot = video.openOrClosedShadowRoot;
if (!shadowRoot) {
return;
}
let { clientX, clientY } = event;
let winUtils = this.content.windowUtils;
// We use winUtils.nodesFromRect instead of document.elementsFromPoint,
// since document.elementsFromPoint always flushes layout. The 1's in that
// function call are for the size of the rect that we want, which is 1x1.
//
// We pass the aOnlyVisible boolean argument to check that the video isn't
// occluded by anything visible at the point of mousedown. If it is, we'll
// ignore the mousedown.
let elements = winUtils.nodesFromRect(clientX, clientY, 1, 1, 1, 1, true,
false, true /* aOnlyVisible */);
if (!Array.from(elements).includes(video)) {
return;
}
let toggle = shadowRoot.getElementById("pictureInPictureToggleButton");
if (this.isMouseOverToggle(toggle, event)) {
state.isClickingToggle = true;
state.clickedElement = Cu.getWeakReference(event.originalTarget);
event.stopImmediatePropagation();
let pipEvent =
new this.content.CustomEvent("MozTogglePictureInPicture", {
bubbles: true,
});
video.dispatchEvent(pipEvent);
// Since we've initiated Picture-in-Picture, we can go ahead and
// hide the toggle now.
this.onMouseLeaveVideo(video);
}
}
/**
* Called for mousedown, pointerup, mouseup and click events. If we
* detected that the user is clicking on the Picture-in-Picture toggle,
* these events are cancelled in the capture-phase before they reach
* content. The state for suppressing these events is cleared on the
* click event (unless the mouseup occurs on a different element from
* the mousedown, in which case, the state is cleared on mouseup).
*
* @param {Event} event A mousedown, pointerup, mouseup or click event.
*/
onMouseButtonEvent(event) {
let state = this.docState;
if (state.isClickingToggle) {
event.stopImmediatePropagation();
// If this is a mouseup event, check to see if we have a record of what
// the original target was on pointerdown. If so, and if it doesn't match
// the mouseup original target, that means we won't get a click event, and
// we can clear the "clicking the toggle" state right away.
//
// Otherwise, we wait for the click event to do that.
let isMouseUpOnOtherElement =
event.type == "mouseup" &&
(!state.clickedElement ||
state.clickedElement.get() != event.originalTarget);
if (isMouseUpOnOtherElement || event.type == "click") {
// The click is complete, so now we reset the state so that
// we stop suppressing these events.
state.isClickingToggle = false;
state.clickedElement = null;
}
}
}
/**
* Called for each mousemove event when we're tracking those events to
* determine if the cursor is hovering over a <video>.
*
* @param {Event} event The mousemove event.
*/
onMouseMove(event) {
let state = this.docState;
state.lastMouseMoveEvent = event;
state.mousemoveDeferredTask.arm();
}
/**
* Called by the DeferredTask after MOUSEMOVE_PROCESSING_DELAY_MS
* milliseconds. Checked to see if that mousemove happens to be overtop of
* any interesting <video> elements that we want to display the toggle
* on. If so, puts the toggle on that video.
*/
checkLastMouseMove() {
let state = this.docState;
let event = state.lastMouseMoveEvent;
let { clientX, clientY } = event;
let winUtils = this.content.windowUtils;
// We use winUtils.nodesFromRect instead of document.elementsFromPoint,
// since document.elementsFromPoint always flushes layout. The 1's in that
// function call are for the size of the rect that we want, which is 1x1.
let elements = winUtils.nodesFromRect(clientX, clientY, 1, 1, 1, 1, true,
false, false);
for (let element of elements) {
if (state.weakVisibleVideos.has(element) &&
!element.isCloningElementVisually) {
this.onMouseOverVideo(element, event);
return;
}
}
let oldOverVideo = state.weakOverVideo && state.weakOverVideo.get();
if (oldOverVideo) {
this.onMouseLeaveVideo(oldOverVideo);
}
}
/**
* Called once it has been determined that the mouse is overtop of a video
* that is in the viewport.
*
* @param {Element} video The video the mouse is over.
*/
onMouseOverVideo(video, event) {
let state = this.docState;
let oldOverVideo = state.weakOverVideo && state.weakOverVideo.get();
let shadowRoot = video.openOrClosedShadowRoot;
// It seems from automated testing that if it's still very early on in the
// lifecycle of a <video> element, it might not yet have a shadowRoot,
// in which case, we can bail out here early.
if (!shadowRoot) {
if (oldOverVideo) {
// We also clear the hover state on the old video we were hovering,
// if there was one.
this.onMouseLeaveVideo(oldOverVideo);
}
return;
}
let toggle = shadowRoot.getElementById("pictureInPictureToggleButton");
if (oldOverVideo) {
if (oldOverVideo == video) {
// If we're still hovering the old video, we might have entered or
// exited the toggle region.
this.checkHoverToggle(toggle, event);
return;
}
// We had an old video that we were hovering, and we're not hovering
// it anymore. Let's leave it.
this.onMouseLeaveVideo(oldOverVideo);
}
state.weakOverVideo = Cu.getWeakReference(video);
let controlsOverlay = shadowRoot.querySelector(".controlsOverlay");
InspectorUtils.addPseudoClassLock(controlsOverlay, ":hover");
// Now that we're hovering the video, we'll check to see if we're
// hovering the toggle too.
this.checkHoverToggle(toggle, event);
}
/**
* Checks if a mouse event is happening over a toggle element. If it is,
* sets the :hover pseudoclass on it. Otherwise, it clears the :hover
* pseudoclass.
*
* @param {Element} toggle The Picture-in-Picture toggle to check.
* @param {MouseEvent} event A MouseEvent to test.
*/
checkHoverToggle(toggle, event) {
if (this.isMouseOverToggle(toggle, event)) {
InspectorUtils.addPseudoClassLock(toggle, ":hover");
} else {
InspectorUtils.removePseudoClassLock(toggle, ":hover");
}
}
/**
* Called once it has been determined that the mouse is no longer overlapping
* a video that we'd previously called onMouseOverVideo with.
*
* @param {Element} video The video that the mouse left.
*/
onMouseLeaveVideo(video) {
let state = this.docState;
let shadowRoot = video.openOrClosedShadowRoot;
if (shadowRoot) {
let controlsOverlay = shadowRoot.querySelector(".controlsOverlay");
let toggle = shadowRoot.getElementById("pictureInPictureToggleButton");
InspectorUtils.removePseudoClassLock(controlsOverlay, ":hover");
InspectorUtils.removePseudoClassLock(toggle, ":hover");
}
state.weakOverVideo = null;
}
/**
* Given a reference to a Picture-in-Picture toggle element, determines
* if a MouseEvent event is occurring within its bounds.
*
* @param {Element} toggle The Picture-in-Picture toggle.
* @param {MouseEvent} event A MouseEvent to test.
*
* @return {Boolean}
*/
isMouseOverToggle(toggle, event) {
let toggleRect =
toggle.ownerGlobal.windowUtils.getBoundsWithoutFlushing(toggle);
let { clientX, clientY } = event;
return clientX >= toggleRect.left &&
clientX <= toggleRect.right &&
clientY >= toggleRect.top &&
clientY <= toggleRect.bottom;
}
/**
* This is a test-only function that returns true if a video is being tracked
* for mouseover events after having intersected the viewport.
*/
static isTracking(video) {
return gWeakIntersectingVideosForTesting.has(video);
}
}
class PictureInPictureChild extends ActorChild {
static videoIsPlaying(video) {
return !!(video.currentTime > 0 && !video.paused && !video.ended && video.readyState > 2);
}
handleEvent(event) {
switch (event.type) {
case "MozTogglePictureInPicture": {
if (event.isTrusted) {
this.togglePictureInPicture(event.target);
}
break;
}
case "pagehide": {
// The originating video's content document has unloaded,
// so close Picture-in-Picture.
this.closePictureInPicture();
break;
}
case "play": {
this.mm.sendAsyncMessage("PictureInPicture:Playing");
break;
}
case "pause": {
this.mm.sendAsyncMessage("PictureInPicture:Paused");
break;
}
}
}
get weakVideo() {
if (gWeakVideo) {
return gWeakVideo.get();
}
return null;
}
get weakPlayerContent() {
if (gWeakPlayerContent) {
return gWeakPlayerContent.get();
}
return null;
}
/**
* Tells the parent to open a Picture-in-Picture window hosting
* a clone of the passed video. If we know about a pre-existing
* Picture-in-Picture window existing, this tells the parent to
* close it before opening the new one.
*
* @param {Element} video The <video> element to view in a Picture
* in Picture window.
*
* @return {Promise}
* @resolves {undefined} Once the new Picture-in-Picture window
* has been requested.
*/
async togglePictureInPicture(video) {
if (this.inPictureInPicture(video)) {
await this.closePictureInPicture();
} else {
if (this.weakVideo) {
// There's a pre-existing Picture-in-Picture window for a video
// in this content process. Send a message to the parent to close
// the Picture-in-Picture window.
await this.closePictureInPicture();
}
gWeakVideo = Cu.getWeakReference(video);
this.mm.sendAsyncMessage("PictureInPicture:Request", {
playing: PictureInPictureChild.videoIsPlaying(video),
videoHeight: video.videoHeight,
videoWidth: video.videoWidth,
});
}
}
/**
* Returns true if the passed video happens to be the one that this
* content process is running in a Picture-in-Picture window.
*
* @param {Element} video The <video> element to check.
*
* @return {Boolean}
*/
inPictureInPicture(video) {
return this.weakVideo === video;
}
/**
* Tells the parent to close a pre-existing Picture-in-Picture
* window.
*
* @return {Promise}
*
* @resolves {undefined} Once the pre-existing Picture-in-Picture
* window has unloaded.
*/
async closePictureInPicture() {
if (this.weakVideo) {
this.untrackOriginatingVideo(this.weakVideo);
}
this.mm.sendAsyncMessage("PictureInPicture:Close", {
browingContextId: this.docShell.browsingContext.id,
});
if (this.weakPlayerContent) {
if (!this.weakPlayerContent.closed) {
await new Promise(resolve => {
this.weakPlayerContent.addEventListener("unload", resolve,
{ once: true });
});
}
// Nothing should be holding a reference to the Picture-in-Picture
// player window content at this point, but just in case, we'll
// clear the weak reference directly so nothing else can get a hold
// of it from this angle.
gWeakPlayerContent = null;
}
}
receiveMessage(message) {
switch (message.name) {
case "PictureInPicture:SetupPlayer": {
this.setupPlayer();
break;
}
case "PictureInPicture:Play": {
this.play();
break;
}
case "PictureInPicture:Pause": {
this.pause();
break;
}
}
}
/**
* Keeps an eye on the originating video's document. If it ever
* goes away, this will cause the Picture-in-Picture window for any
* of its content to go away as well.
*/
trackOriginatingVideo(originatingVideo) {
let originatingWindow = originatingVideo.ownerGlobal;
if (originatingWindow) {
originatingWindow.addEventListener("pagehide", this);
originatingVideo.addEventListener("play", this);
originatingVideo.addEventListener("pause", this);
}
}
/**
* Stops tracking the originating video's document. This should
* happen once the Picture-in-Picture window goes away (or is about
* to go away), and we no longer care about hearing when the originating
* window's document unloads.
*/
untrackOriginatingVideo(originatingVideo) {
let originatingWindow = originatingVideo.ownerGlobal;
if (originatingWindow) {
originatingWindow.removeEventListener("pagehide", this);
originatingVideo.removeEventListener("play", this);
originatingVideo.removeEventListener("pause", this);
}
}
/**
* Runs in an instance of PictureInPictureChild for the
* player window's content, and not the originating video
* content. Sets up the player so that it clones the originating
* video. If anything goes wrong during set up, a message is
* sent to the parent to close the Picture-in-Picture window.
*
* @return {Promise}
* @resolves {undefined} Once the player window has been set up
* properly, or a pre-existing Picture-in-Picture window has gone
* away due to an unexpected error.
*/
async setupPlayer() {
let originatingVideo = this.weakVideo;
if (!originatingVideo) {
// If the video element has gone away before we've had a chance to set up
// Picture-in-Picture for it, tell the parent to close the Picture-in-Picture
// window.
await this.closePictureInPicture();
return;
}
let webProgress = this.mm
.docShell.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIWebProgress);
if (webProgress.isLoadingDocument) {
await new Promise(resolve => {
this.mm.addEventListener("load", resolve, {
once: true,
mozSystemGroup: true,
capture: true,
});
});
}
let doc = this.content.document;
let playerVideo = originatingVideo.cloneNode();
playerVideo.removeAttribute("controls");
// Mute the video and rely on the originating video's audio playback.
// This way, we sidestep the AutoplayPolicy blocking stuff.
playerVideo.muted = true;
// Force the player video to assume maximum height and width of the
// containing window
playerVideo.style.height = "100vh";
playerVideo.style.width = "100vw";
// And now try to get rid of as much surrounding whitespace as possible.
playerVideo.style.margin = "0";
doc.body.style.overflow = "hidden";
doc.body.style.margin = "0";
doc.body.appendChild(playerVideo);
originatingVideo.cloneElementVisually(playerVideo);
this.trackOriginatingVideo(originatingVideo);
this.content.addEventListener("unload", () => {
if (this.weakVideo) {
this.weakVideo.stopCloningElementVisually();
}
gWeakVideo = null;
}, { once: true });
gWeakPlayerContent = Cu.getWeakReference(this.content);
}
play() {
let video = this.weakVideo;
if (video) {
video.play();
}
}
pause() {
let video = this.weakVideo;
if (video) {
video.pause();
}
}
}