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Issue 2706673002:
Mark elements as viewport constrained when they become sticky positioned (Closed)
| Index: third_party/WebKit/LayoutTests/fast/css/sticky/sticky-style-change.html |
| diff --git a/third_party/WebKit/LayoutTests/fast/css/sticky/sticky-style-change.html b/third_party/WebKit/LayoutTests/fast/css/sticky/sticky-style-change.html |
| new file mode 100644 |
| index 0000000000000000000000000000000000000000..deef30720fa01307ff97bd80bd0b881c5c04ac77 |
| --- /dev/null |
| +++ b/third_party/WebKit/LayoutTests/fast/css/sticky/sticky-style-change.html |
| @@ -0,0 +1,68 @@ |
| +<!DOCTYPE html> |
| +<script> |
| +if (window.internals) { |
| + internals.settings.setCSSStickyPositionEnabled(true); |
| +} |
| +</script> |
| + |
| +<html> |
| +<head> |
| +<style> |
| + body { |
| + margin: 0; |
| + overflow: hidden; /* hide scrollbars */ |
| + } |
| + |
| + .container { |
| + height: 2000px; |
| + } |
| + |
| + .box { |
| + height: 50px; |
| + } |
| + |
| + .sticky { |
| + position: sticky; |
| + top: 50px; |
| + background-color: green; |
| + } |
| +</style> |
| +<script> |
| + if (window.testRunner) |
| + testRunner.waitUntilDone() |
| + |
| + function doTest() |
| + { |
| + const sticky = document.querySelector('.sticky'); |
| + sticky.style.position = 'relative'; |
| + |
| + // Force layout. |
| + var x = sticky.offsetTop; |
|
flackr
2017/02/22 14:45:42
nit: just call stickyoffsetTop;
smcgruer
2017/02/22 15:26:31
Done.
|
| + |
| + sticky.style.position = 'sticky'; |
| + |
| + // Yield to allow the sticky change to 'stick'. |
| + // TODO(smcgruer): If replaced with call to offsetTop, the sticky still |
| + // breaks but blink seems to scroll first and then draw the item so it |
| + // *looks* correct for the comparison. Expected? |
|
flackr
2017/02/22 14:45:42
I think what happens is the change to position sti
smcgruer
2017/02/22 15:26:31
Done.
|
| + setTimeout(function() { |
| + window.scrollTo(0, 100); |
| + if (window.testRunner) |
| + testRunner.notifyDone(); |
| + }, 0); |
| + } |
| + |
| + window.addEventListener('load', function() { |
| + // The timeout is required to force CompositingInputsUpdater to fire at least |
| + // once before we change the position. |
| + // TODO(smcgruer): For some reason, a rAF does not wait for this, but a 0 second timeout does. |
|
flackr
2017/02/22 14:45:42
This sounds likely to flake, I think setTimeout is
smcgruer
2017/02/22 15:26:31
Done.
|
| + setTimeout(doTest, 0); |
| + }); |
| +</script> |
| +</head> |
| +<body> |
| + <div class="container"> |
| + <div class="sticky box"></div> |
| + </div> |
| +</body> |
| +</html> |
