зеркало из https://github.com/mozilla/gecko-dev.git
368 строки
11 KiB
JavaScript
368 строки
11 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/. */
|
|
|
|
const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
|
|
|
|
var EXPORTED_SYMBOLS = ["AutoScrollController"];
|
|
|
|
class AutoScrollController {
|
|
constructor(global) {
|
|
this._scrollable = null;
|
|
this._scrolldir = "";
|
|
this._startX = null;
|
|
this._startY = null;
|
|
this._screenX = null;
|
|
this._screenY = null;
|
|
this._lastFrame = null;
|
|
this._autoscrollHandledByApz = false;
|
|
this._scrollId = null;
|
|
this._global = global;
|
|
this.autoscrollLoop = this.autoscrollLoop.bind(this);
|
|
|
|
global.addMessageListener("Autoscroll:Stop", this);
|
|
}
|
|
|
|
isAutoscrollBlocker(node) {
|
|
let mmPaste = Services.prefs.getBoolPref("middlemouse.paste");
|
|
let mmScrollbarPosition = Services.prefs.getBoolPref(
|
|
"middlemouse.scrollbarPosition"
|
|
);
|
|
let content = node.ownerGlobal;
|
|
|
|
while (node) {
|
|
if (
|
|
(node instanceof content.HTMLAnchorElement ||
|
|
node instanceof content.HTMLAreaElement) &&
|
|
node.hasAttribute("href")
|
|
) {
|
|
return true;
|
|
}
|
|
|
|
if (
|
|
mmPaste &&
|
|
(node instanceof content.HTMLInputElement ||
|
|
node instanceof content.HTMLTextAreaElement)
|
|
) {
|
|
return true;
|
|
}
|
|
|
|
if (
|
|
node instanceof content.XULElement &&
|
|
mmScrollbarPosition &&
|
|
(node.localName == "scrollbar" || node.localName == "scrollcorner")
|
|
) {
|
|
return true;
|
|
}
|
|
|
|
node = node.parentNode;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
isScrollableElement(aNode) {
|
|
let content = aNode.ownerGlobal;
|
|
if (aNode instanceof content.HTMLElement) {
|
|
return !(aNode instanceof content.HTMLSelectElement) || aNode.multiple;
|
|
}
|
|
|
|
return aNode instanceof content.XULElement;
|
|
}
|
|
|
|
getXBLNodes(parent, array) {
|
|
let content = parent.ownerGlobal;
|
|
let anonNodes = content.document.getAnonymousNodes(parent);
|
|
let nodes = Array.from(anonNodes || parent.childNodes || []);
|
|
for (let node of nodes) {
|
|
if (node.nodeName == "children") {
|
|
return true;
|
|
}
|
|
if (this.getXBLNodes(node, array)) {
|
|
array.push(node);
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
*parentNodeIterator(aNode) {
|
|
let content = aNode.ownerGlobal;
|
|
|
|
while (aNode) {
|
|
yield aNode;
|
|
|
|
let parent = aNode.parentNode;
|
|
if (parent && parent instanceof content.XULElement) {
|
|
let anonNodes = content.document.getAnonymousNodes(parent);
|
|
if (anonNodes && !Array.from(anonNodes).includes(aNode)) {
|
|
// XBL elements are skipped by parentNode property.
|
|
// Yield elements between parent and <children> here.
|
|
let nodes = [];
|
|
this.getXBLNodes(parent, nodes);
|
|
for (let node of nodes) {
|
|
yield node;
|
|
}
|
|
}
|
|
}
|
|
|
|
aNode = parent;
|
|
}
|
|
}
|
|
|
|
findNearestScrollableElement(aNode) {
|
|
let content = aNode.ownerGlobal;
|
|
|
|
// this is a list of overflow property values that allow scrolling
|
|
const scrollingAllowed = ["scroll", "auto"];
|
|
|
|
// go upward in the DOM and find any parent element that has a overflow
|
|
// area and can therefore be scrolled
|
|
this._scrollable = null;
|
|
for (let node of this.parentNodeIterator(aNode)) {
|
|
// do not use overflow based autoscroll for <html> and <body>
|
|
// Elements or non-html/non-xul elements such as svg or Document nodes
|
|
// also make sure to skip select elements that are not multiline
|
|
if (!this.isScrollableElement(node)) {
|
|
continue;
|
|
}
|
|
|
|
var overflowx = node.ownerGlobal
|
|
.getComputedStyle(node)
|
|
.getPropertyValue("overflow-x");
|
|
var overflowy = node.ownerGlobal
|
|
.getComputedStyle(node)
|
|
.getPropertyValue("overflow-y");
|
|
// we already discarded non-multiline selects so allow vertical
|
|
// scroll for multiline ones directly without checking for a
|
|
// overflow property
|
|
var scrollVert =
|
|
node.scrollTopMax &&
|
|
(node instanceof content.HTMLSelectElement ||
|
|
scrollingAllowed.includes(overflowy));
|
|
|
|
// do not allow horizontal scrolling for select elements, it leads
|
|
// to visual artifacts and is not the expected behavior anyway
|
|
if (
|
|
!(node instanceof content.HTMLSelectElement) &&
|
|
node.scrollLeftMin != node.scrollLeftMax &&
|
|
scrollingAllowed.includes(overflowx)
|
|
) {
|
|
this._scrolldir = scrollVert ? "NSEW" : "EW";
|
|
this._scrollable = node;
|
|
break;
|
|
} else if (scrollVert) {
|
|
this._scrolldir = "NS";
|
|
this._scrollable = node;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!this._scrollable) {
|
|
this._scrollable = aNode.ownerGlobal;
|
|
if (this._scrollable.scrollMaxX != this._scrollable.scrollMinX) {
|
|
this._scrolldir =
|
|
this._scrollable.scrollMaxY != this._scrollable.scrollMinY
|
|
? "NSEW"
|
|
: "EW";
|
|
} else if (this._scrollable.scrollMaxY != this._scrollable.scrollMinY) {
|
|
this._scrolldir = "NS";
|
|
} else if (this._scrollable.frameElement) {
|
|
this.findNearestScrollableElement(this._scrollable.frameElement);
|
|
} else {
|
|
this._scrollable = null; // abort scrolling
|
|
}
|
|
}
|
|
}
|
|
|
|
startScroll(event) {
|
|
this.findNearestScrollableElement(event.originalTarget);
|
|
|
|
if (!this._scrollable) {
|
|
return;
|
|
}
|
|
|
|
let content = event.originalTarget.ownerGlobal;
|
|
|
|
// In some configurations like Print Preview, content.performance
|
|
// (which we use below) is null. Autoscrolling is broken in Print
|
|
// Preview anyways (see bug 1393494), so just don't start it at all.
|
|
if (!content.performance) {
|
|
return;
|
|
}
|
|
|
|
let domUtils = content.windowUtils;
|
|
let scrollable = this._scrollable;
|
|
if (scrollable instanceof Ci.nsIDOMWindow) {
|
|
// getViewId() needs an element to operate on.
|
|
scrollable = scrollable.document.documentElement;
|
|
}
|
|
this._scrollId = null;
|
|
try {
|
|
this._scrollId = domUtils.getViewId(scrollable);
|
|
} catch (e) {
|
|
// No view ID - leave this._scrollId as null. Receiving side will check.
|
|
}
|
|
let presShellId = domUtils.getPresShellId();
|
|
let [result] = this._global.sendSyncMessage("Autoscroll:Start", {
|
|
scrolldir: this._scrolldir,
|
|
screenX: event.screenX,
|
|
screenY: event.screenY,
|
|
scrollId: this._scrollId,
|
|
presShellId,
|
|
});
|
|
if (!result.autoscrollEnabled) {
|
|
this._scrollable = null;
|
|
return;
|
|
}
|
|
|
|
Services.els.addSystemEventListener(this._global, "mousemove", this, true);
|
|
this._global.addEventListener("pagehide", this, true);
|
|
|
|
this._ignoreMouseEvents = true;
|
|
this._startX = event.screenX;
|
|
this._startY = event.screenY;
|
|
this._screenX = event.screenX;
|
|
this._screenY = event.screenY;
|
|
this._scrollErrorX = 0;
|
|
this._scrollErrorY = 0;
|
|
this._autoscrollHandledByApz = result.usingApz;
|
|
|
|
if (!result.usingApz) {
|
|
// If the browser didn't hand the autoscroll off to APZ,
|
|
// scroll here in the main thread.
|
|
this.startMainThreadScroll();
|
|
} else {
|
|
// Even if the browser did hand the autoscroll to APZ,
|
|
// APZ might reject it in which case it will notify us
|
|
// and we need to take over.
|
|
Services.obs.addObserver(this, "autoscroll-rejected-by-apz");
|
|
}
|
|
}
|
|
|
|
startMainThreadScroll() {
|
|
let content = this._global.content;
|
|
this._lastFrame = content.performance.now();
|
|
content.requestAnimationFrame(this.autoscrollLoop);
|
|
}
|
|
|
|
stopScroll() {
|
|
if (this._scrollable) {
|
|
this._scrollable.mozScrollSnap();
|
|
this._scrollable = null;
|
|
|
|
Services.els.removeSystemEventListener(
|
|
this._global,
|
|
"mousemove",
|
|
this,
|
|
true
|
|
);
|
|
this._global.removeEventListener("pagehide", this, true);
|
|
if (this._autoscrollHandledByApz) {
|
|
Services.obs.removeObserver(this, "autoscroll-rejected-by-apz");
|
|
}
|
|
}
|
|
}
|
|
|
|
accelerate(curr, start) {
|
|
const speed = 12;
|
|
var val = (curr - start) / speed;
|
|
|
|
if (val > 1) {
|
|
return val * Math.sqrt(val) - 1;
|
|
}
|
|
if (val < -1) {
|
|
return val * Math.sqrt(-val) + 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
roundToZero(num) {
|
|
if (num > 0) {
|
|
return Math.floor(num);
|
|
}
|
|
return Math.ceil(num);
|
|
}
|
|
|
|
autoscrollLoop(timestamp) {
|
|
if (!this._scrollable) {
|
|
// Scrolling has been canceled
|
|
return;
|
|
}
|
|
|
|
// avoid long jumps when the browser hangs for more than
|
|
// |maxTimeDelta| ms
|
|
const maxTimeDelta = 100;
|
|
var timeDelta = Math.min(maxTimeDelta, timestamp - this._lastFrame);
|
|
// we used to scroll |accelerate()| pixels every 20ms (50fps)
|
|
var timeCompensation = timeDelta / 20;
|
|
this._lastFrame = timestamp;
|
|
|
|
var actualScrollX = 0;
|
|
var actualScrollY = 0;
|
|
// don't bother scrolling vertically when the scrolldir is only horizontal
|
|
// and the other way around
|
|
if (this._scrolldir != "EW") {
|
|
var y = this.accelerate(this._screenY, this._startY) * timeCompensation;
|
|
var desiredScrollY = this._scrollErrorY + y;
|
|
actualScrollY = this.roundToZero(desiredScrollY);
|
|
this._scrollErrorY = desiredScrollY - actualScrollY;
|
|
}
|
|
if (this._scrolldir != "NS") {
|
|
var x = this.accelerate(this._screenX, this._startX) * timeCompensation;
|
|
var desiredScrollX = this._scrollErrorX + x;
|
|
actualScrollX = this.roundToZero(desiredScrollX);
|
|
this._scrollErrorX = desiredScrollX - actualScrollX;
|
|
}
|
|
|
|
this._scrollable.scrollBy({
|
|
left: actualScrollX,
|
|
top: actualScrollY,
|
|
behavior: "instant",
|
|
});
|
|
|
|
this._scrollable.ownerGlobal.requestAnimationFrame(this.autoscrollLoop);
|
|
}
|
|
|
|
handleEvent(event) {
|
|
if (event.type == "mousemove") {
|
|
this._screenX = event.screenX;
|
|
this._screenY = event.screenY;
|
|
} else if (event.type == "mousedown") {
|
|
if (
|
|
!this._scrollable &&
|
|
!this.isAutoscrollBlocker(event.originalTarget)
|
|
) {
|
|
this.startScroll(event);
|
|
}
|
|
} else if (event.type == "pagehide") {
|
|
if (this._scrollable) {
|
|
var doc = this._scrollable.ownerDocument || this._scrollable.document;
|
|
if (doc == event.target) {
|
|
this._global.sendAsyncMessage("Autoscroll:Cancel");
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
receiveMessage(msg) {
|
|
switch (msg.name) {
|
|
case "Autoscroll:Stop": {
|
|
this.stopScroll();
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
observe(subject, topic, data) {
|
|
if (topic === "autoscroll-rejected-by-apz") {
|
|
// The caller passes in the scroll id via 'data'.
|
|
if (data == this._scrollId) {
|
|
this._autoscrollHandledByApz = false;
|
|
this.startMainThreadScroll();
|
|
Services.obs.removeObserver(this, "autoscroll-rejected-by-apz");
|
|
}
|
|
}
|
|
}
|
|
}
|