Before this change, a formatting context was responsible for layout of
absolutely positioned boxes whose FC root box was their parent (either
directly or indirectly). This only worked correctly when the containing
block of the absolutely positioned child did not escape the FC root.
This is because the width and height of an absolutely positioned box are
resolved based on the size of its containing block, so we needed to
ensure that the containing block's layout was completed before laying
out an absolutely positioned box.
With this change, the layout of absolutely positioned boxes is delayed
until the FC responsible for the containing block's layout is complete.
This has affected the way we calculate the static position. It is no
longer possible to ask the FC for a box's static position, as this FC's
state might be gone by the time the layout for absolutely positioned
elements occurs. Instead, the "static position rectangle" (a concept
from the spec) is saved in the layout state, along with information on
how to align the box within this rectangle when its width and height are
resolved.
Absolutely positioned boxes do not affect the size of the formatting
context box they belong to, so it's safe to skip their layout entirely
when calculating intrinsic size.
FormattingContext::run() does not allow reentrancy, so it's safe to
save and access layout mode from FC object. This avoids need to drill it
through methods of a formatting context and makes it clear that this
value could never be changed after FC construction.
Root formatting context box is passed into constructor and saved in FC,
so it's possible to access it from there instead of passing the same
box into run().
This adds a new script for linting WebIDL files, and adds it to the set
of scripts Meta/lint-ci.sh runs. Initially, this script does just one
thing: normalizes IDL definition lines so they start with four spaces.
This change takes all existing WebIDL files in the repo that had
definition lines without four leading spaces, and fixes them so they
have four leading spaces.
This change ensures that the value sanitization algorithm is run and
the text cursor is set to the correct position when the type attribute
of an input is changed.
Instead of throwing all pseudo-element rules in one bucket, let's have
one bucket per pseudo-element.
This means we only run ::before rules for ::before pseudo-elements,
only ::after rules for ::after, etc.
Average style update time on https://tailwindcss.com/ 250ms -> 215ms.
Once we know the final value of the `content` property for a
pseudo-element, we can bail early if the value is `none` or `normal`
(note that `normal` only applies to ::before and ::after).
In those cases, no pseudo-element will be generated, so everything
that follows in StyleComputer would be wasted work.
This noticeably improves performance on many pages, such as
https://tailwindcss.com/ where style updates go from 360ms -> 250ms.
This makes the way we've implemented the CSS `revert` keyword a lot less
expensive.
Until now, we were making a deep copy of all property values at the
start of each cascade origin. (Those are the values that `revert` would
bring us back to if encountered.)
With this patch, the revert property set becomes a shallow copy, and we
only clone the property set if the cascade ends up writing something.
This knocks a 5% profile item down to 1.3% on https://tailwindcss.com
Instead of asking Skia for the family name every time we're called,
just cache the string once and make subsequent calls fast.
This knocks a 3.2% item off the profile entirely on
https://tailwindcss.com (at least on macOS with the CoreText backend)
This brings back the optimization we had in the old OpenType
implementation where we cache lookup tables for code point / glyph ID
mappings.
This noticeably improves performance on https://tailwindcss.com/ by
knocking an 8% profile item down to 0.2%. :^)
Skia is more permissive when it comes to font loading, compared to our
own OpenType implementation, which it has superseded, parsing an invalid
TTF does not result in an error but rather produces a font that is
incorrectly displayed. This change updates the FontLoader to address
this behavior and to stop attempting to parse a font as a last resort
when format detection has failed.
Fixes regression on x.com when text is not displayed introduced in
a9d5a99568
This script only checks Tests/AK, and verifies that all source files
that match Tests/AK/*.cpp are listed in the CMakeLists.txt.
This is a bit excessive. We don't have this check for any other test
files. This sort of error will definitely ™️ be caught in review.
Also, remove blank lines. (https://w3c.github.io/aria/#ARIAMixin source
doesn’t have any blank lines, and it’s not clear that the blank lines in
ours follow any intended structure/logic.)
This change adds the [CEReactions] attributes to all ARIA attributes in
the ARIAMixin WebIDL — as required by the WebIDL in the current spec at
https://w3c.github.io/aria/#ARIAMixin, and by the WPT test case at
http://wpt.live/custom-elements/reactions/AriaMixin-string-attributes.html,
and as implemented in other existing engines.
Otherwise, without this change, Ladybird doesn’t conform to the current
spec, fails all those tests, and isn’t interoperable with other engines.
CMake reads CMakePresets.json, which is before it reads CMakeLists.txt.
This causes CMake Error: Unrecognized "version" field if the version of
CMake is older than support for presets, or the version field of
presets.
The fix is to check CMake version in ladybird.sh before trying to create
the build directory.
Co-Authored-By: Andrew Kaster <andrew@ladybird.org>
If grid-template-rows or grid-template-columns queried for a box that is
not a grid container, the result should be computed value instead of
null.
Fixes crashing in inspector.
Instead of only bucketing these by class name, let's also bucket by
tag name and ID.
Reduces the number of selectors evaluated on https://tailwindcss.com/
from 2.9% to 1.9%.
By filtering first, we end up allocating much less vector space
most of the time.
This is mostly helpful in pathological cases where there's a huge number
of rules present, but most of them get rejected early.
Previously, there was a bug in the specification that would cause an
assertion failure, due to the abort event being fired before all
dependent signals were aborted.
That's awkward, but getComputedStyle needs to return used track values
for gridTemplateColumns and gridTemplateRows properties. This change
implements it by saving style values with used values into layout state,
so it could be assigned to paintables during LayoutState::commit() and
later accessed by style_value_for_property().
I haven't seen it used in the wild, but WPT grid tests extensively use
it. For example this change helps to go from 0/10 to 8/10 on this test:
https://wpt.live/css/css-grid/layout-algorithm/grid-fit-content-percentage.html
Before this change, the ancestor filter would only reject rules that
required a certain set of descendant strings (class, ID or tag name)
to be present in the current element's ancestor chain.
An immediate child is also a descendant, so we can include this
relationship in the ancestor filter as well.
This substantially improves the efficiency of the ancestor filter on
websites using Tailwind CSS.
For example, https://tailwindcss.com/ itself goes from full style
updates taking ~1400ms to ~350ms. Still *way* too long, but a huge
improvement nonetheless.
By bucketing these seletors by class or ID, we can avoid running them
in more cases.
Before, we were only avoiding them if the context element wasn't a div.
Now we avoid them for any element that doesn't have that specific class
or ID.
This reduces the number of selectors ran on https://vercel.com by a bit
more, from 1.90% to 1.65%.
These are just roundabout ways of writing .foo, so we can still put them
in the rules-by-class bucket and skip running them when the element
doesn't have that class.
Note that :is(.foo .bar) is also bucketed as a class rule, since the
context element must have the `bar` class for the selector to match.
This is a massive speedup on https://vercel.com/ as it cuts the number
of selectors we actually evaluate from 7.0% to 1.9%.
