Fixes bug when "clip" property does not affect abspos children.
This change makes "clip" property to be applied together with
"overflow: hidden" in `apply_clip_overflow_rect()` that already
handles abspos children correctly.
Instead of calling to_lowercase() on two strings for every step while
iterating over the HTMLCollection returned by getElementsByTagName(),
we now cache the lowercased tag name beforehand and reuse it.
2.4x speed-up on WebKit/PerformanceTests/DOM/DOMDivWalk.html
User styles are applied after the UserAgent's built-in styles, and
before the Author styles that are part of the web page.
Because they're neither part of the page, but can still be modified
while the page is open, caching is a little tricky. The approach here
is to piggy-back on the StyleComputer's rule caches, which already get
rebuilt whenever the styles change. This is not the smartest approach,
since it means re-parsing the style sheet more often than is necessary,
but it's simple and works. :^)
This matches if the element has a placeholder, and that placeholder is
currently visible. This applies to `<input>` and `<textarea>` elements,
but our `<textarea>` is very limited so does not support placeholders.
As noted in a9620d8784 we don't currently
set the target element so this does not function, so no tests. But it
should work once we have a fleshed out Navigables implementation. :^)
Grid specification https://www.w3.org/TR/css-grid-2/#z-order defines
special painting order for grid items which should be the same as for
defined for inline-blocks in CSS2.
Check the width of the next token after white space to decide line
breaks. The next width can also be the total width of multiple tokens.
This better follows the CSS Text specification and matches behavior of
other browsers.
Fixes#20388.
We still don't know how to resolve font-relative lengths in <img sizes>
since we don't always have font size information available at this stage
in the pipeline, but we can at least handle viewport-relative lengths.
This fixes an issue on many websites where low-resolution images were
loaded (appropriate for a small viewport) even when the viewport is big.
This is all of them currently, except Length, because we lack the needed
information to be able to expand font-relative lengths.
The whole way `expand_unresolved_values()` works is awkward, but at some
point we'll be able to run the simplification algorithm on the
calculation, which will either return a single value, or a new
calculation that's simplified as much as possible.
Mostly I just wanted that FIXME log message to go away, because it's
overwhelming on certain sites.
And treat them as "auto" for now, per CSS-SIZING-3, with a FIXME about
supporting more layout directions.
This fixes an issue on MDN where `height: max-content` was not
overriding height from non-CSS presentational hints.
