mozilla-central/gfx/layers/apz/test/mochitest/browser_test_position_sticky.js (file symbol)

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/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
/* vim: set sts=2 sw=2 et tw=80: */
"use strict";
Services.scriptloader.loadSubScript(
this
);
Services.scriptloader.loadSubScript(
this
);
add_task(async () => {
function httpURL(filename) {
let chromeURL = getRootDirectory(gTestPath) + filename;
return chromeURL.replace(
);
}
const url = httpURL("helper_position_sticky_flicker.html");
const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, url);
const { rect, scrollbarWidth } = await SpecialPowers.spawn(
tab.linkedBrowser,
[],
async () => {
const sticky = content.document.getElementById("sticky");
// Get the area in the screen coords where the position:sticky element is.
let stickyRect = sticky.getBoundingClientRect();
stickyRect.x += content.window.mozInnerScreenX;
stickyRect.y += content.window.mozInnerScreenY;
// generate some DIVs to make the page complex enough.
for (let i = 1; i <= 120000; i++) {
const div = content.document.createElement("div");
div.innerText = `${i}`;
content.document.body.appendChild(div);
}
await content.wrappedJSObject.promiseApzFlushedRepaints();
await content.wrappedJSObject.waitUntilApzStable();
let w = {},
h = {};
SpecialPowers.DOMWindowUtils.getScrollbarSizes(
content.document.documentElement,
w,
h
);
// Reduce the scrollbar width from the sticky area.
stickyRect.width -= w.value;
return {
rect: stickyRect,
scrollbarWidth: w.value,
};
}
);
// Take a snapshot where the position:sticky element is initially painted.
const reference = await getSnapshot(rect);
let mouseX = window.innerWidth - scrollbarWidth / 2;
let mouseY = tab.linkedBrowser.getBoundingClientRect().y + 5;
// Scroll fast to cause checkerboarding multiple times.
const dragFinisher = await promiseNativeMouseDrag(
window,
mouseX,
mouseY,
0,
window.innerHeight,
100
);
// On debug builds there seems to be no chance that the content process gets
// painted during above promiseNativeMouseDrag call, wait two frames to make
// sure it happens so that this test is likely able to fail without proper
// fix.
if (AppConstants.DEBUG) {
await SpecialPowers.spawn(tab.linkedBrowser, [], async () => {
await content.wrappedJSObject.promiseFrame(content.window);
await content.wrappedJSObject.promiseFrame(content.window);
});
}
// Take a snapshot again where the position:sticky element should be painted.
const snapshot = await getSnapshot(rect);
await dragFinisher();
is(
snapshot,
reference,
"The position:sticky element should stay at the " +
"same place after scrolling on heavy load"
);
BrowserTestUtils.removeTab(tab);
});