File: reading-scroll-forces-anchoring.html

package info (click to toggle)
thunderbird 1%3A115.12.0-1~deb11u1
  • links: PTS, VCS
  • area: main
  • in suites: bullseye
  • size: 3,463,904 kB
  • sloc: cpp: 6,971,272; javascript: 5,208,988; ansic: 3,507,245; python: 1,137,377; asm: 432,531; xml: 205,149; java: 175,761; sh: 116,483; makefile: 22,157; perl: 13,971; objc: 12,561; yacc: 4,583; pascal: 2,840; lex: 1,720; ruby: 1,075; exp: 762; sql: 666; awk: 580; php: 436; lisp: 430; sed: 70; csh: 10
file content (30 lines) | stat: -rw-r--r-- 973 bytes parent folder | download | duplicates (24) 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
 
<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-scroll-anchoring-1/">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<style>
body { height: 1000px }
div { height: 100px }
</style>
<div id="block1">abc</div>
<div id="block2">def</div>
<script>
  // This test verifies that reading window.scrollY forces any pending scroll
  // anchoring adjustment to occur before computing the return value.
  async_test((t) => {
    scrollTo(0, 150);
    requestAnimationFrame(() => {
      step_timeout(() => {
        // Queue scroll anchoring adjustment.
        document.querySelector("#block1").style.height = "200px";

        // Reading scrollY should force both the layout and the adjustment to
        // occur synchronously.
        var y = scrollY;

        assert_equals(y, 250);
        t.done();
      }, 0);
    });
  }, 'Reading scroll position forces scroll anchoring adjustment.');
</script>