We now also more closely follow the spec when computing values for
font-weight and we now:
- Support relative lengths in `calc()`s
- Properly clamp `calc()`s
- Support relative keywords (e.g. lighter, bolder)
- Respect that font-weight can be a non-integer number.
This does expose a few false positives in the font-weight-computed.html
WPT test. This is because we don't recompute non-inherited font-weight
within `recompute_inherited_style` which means that relative keyword
values can fall out of sync with their parent's value. These previously
passed as we treated `bolder` and `lighter` as aliases for `bold` and
`normal` respectively.
There are other places we want to convert font-size into it's computed
form than just when we are loading the font (e.g. computing keyframes).
Gains us 36 WPT passes as we now correctly clamp negative calc values.
As noted, the chunk of this method that deals with animations could do
with some helpers on AbstractElement, but I'm leaving that until it's
clearer how animations and pseudo-elements should interact.
Implements `::slotted()` to enough extent we could pass the imported WPT
test and make substantial layout correctness improvement on
https://www.rottentomatoes.com/
Gains us 112 new passes since we now interpolate keywords (thick, thin,
etc) correctly.
Also loses us 4 WPT tests as we longer clamp negative values produced by
interpolation from the point of view of getComputedStyle (although the
'used' value is still clamped).
`StyleValue`s stored within `ComputedProperties` should be in their
computed forms, this is for various reasons including:
- Inheritance should be of computed values
- Animations should work on computed values
- Triggering transitions should work on computed values
Currently we store `StyleValue`s in an absolutized version of the
specified value - this is equivalent to the computed form in many cases
which is why this hasn't been causing significant issues but there are
some cases - such as `border-*-width` keywords where this is not the
case.
No functionality change as we are yet to implement any properties
This removes the AnimationRefresh argument from `collect_animation_into`
which was added in a9b8840 - it's only effect was disallowing
`UseInitial`s within keyframes when we were doing animated style
updates which I believe is unintentional.
Gains us 214 WPT tests.
The StyleValue stored in m_property_values is already in it's computed
form and it's trivial to pull the underlying value out so there is no
need to store this separately.
Also removes unnecessary handling of percentage values in
`absolutize_values` - this is already handled within `compute_font`.
When starting transitions we compute the after-change style, for any
inherited properties this should include the non-animated value.
Previously we were only inheriting the animated value and treating it as
non-animated so were instead including the animated value.
This commit fixes that by inheriting both the animated and non-animated
values (with the former being stored in `m_animated_property_values`,
and the latter in `m_property_values`).
This gains us 12 new WPT passes.
This brings with it 252 new WPT fails from the various 'events' tests in
css/css-transitions/properties-value-inherit-001.html, however these
also fail in other browsers (Chrome, Edge and Firefox) and the behaviour
that causes these failures is specifically mentioned in the spec.
This reverts 0e3487b9ab.
Back when I made that change, I thought we could make our StyleValue
classes match the typed-om definitions directly. However, they have
different requirements. Typed-om types need to be mutable and GCed,
whereas StyleValues are immutable and ideally wouldn't require a JS VM.
While I was already making such a cataclysmic change, I've moved it into
the StyleValues directory, because it *not* being there has bothered me
for a long time. 😅
This allows them to keep style sheets alive while loading fonts for
them. Fixes some GC crashes seen on the WPT WOFF2 tests after
66a19b8550 stopped FetchRecord leaks from
keeping various other things alive.
Before this change, whenever element's attributes changed, we would add
a flag to "pending invalidation", indicating that all descendants whose
style uses CSS custom properties needed to be recomputed. This resulted
in severe overinvalidation, because we would run invalidation regardless
of whether any custom property on affected element actually changed.
This change takes another approach, and now we decide whether
descendant's style needs to be recomputed based on whether ancestor's
style recomputation results in a change of custom properties, though
this approach adds a little overhead to style computation as now we have
to compare old vs new hashmap of custom properties.
This brings substantial improvement on discord and x.com where, before
this change, advantage of using invalidation sets was lost and we had
to recompute all descendants, because almost all of them use custom
properties.
Fixes bug when `build_matching_rule_set()` mistakenly included all
unlayered rules twice. This was caused by mistakenly including all
unlayered rules into `""` named "service" layer, because we couldn't
tell if FlyString = `""` means no layer or layer named `""`.
Before this change we were running the CSS cascade machinery twice per
element:
- First, to compute the "logical alias mapping context" based on
writing-mode and pals.
- Then, to compute all properties.
This patch factors out the heaviest work from the cascade machinery
to a separate step that can be run only once. This step will:
- Collect all the matching rules for the element
- Resolve custom properties for the element
We still perform the per-element cascade twice, but now this is hogging
less than 1% of CPU time when typing on Discord (compared to 9% before.)
"Arbitrary substitution functions" are a family of functions that
includes var() and attr(). All of them resolve to an arbitrary set of
component values that are not known at parse-time, so they have to be
substituted at computed-value time.
Besides it being nice to follow the spec closely, this means we'll be
able to implement the others (such as `if()` and `inherit()`) more
easily.
The main omission here is the new "spread syntax", which can be
implemented in the future.
Custom properties are required to produce a computed value just like
regular properties. The computed value is defined in the spec as
"specified value with variables substituted, or the guaranteed-invalid
value", though in reality all arbitrary substitution functions should be
substituted, not just `var()`.
To support this, we parse the CSS-wide keywords normally in custom
properties, instead of ignoring them. We don't yet handle all of them
properly, and because that will require us to cascade them like regular
properties. This is just enough to prevent regressions when implementing
ASFs.
Our output in this new test is not quite correct, because of the awkward
way we handle whitespace in property values - so it has 3 spaces in the
middle instead of 1, until that's fixed.
It's possible this computed-value production should go in
cascade_custom_properties(), but I had issues with that. Hopefully once
we start cascading custom properties properly, it'll be clearer how
this should all work.
To support this, how we declare logical property aliases has changed.
Instead of `logical-alias-for` being a list of properties, it's now an
object with a `group` and `mapping`. The group is the name of a logical
property group in LogicalPropertyGroups.json. The mapping is which
side/dimension/corner this property is. Hopefully it's self-explanatory
enough.
The generated code is very much a copy of what was previously in
`StyleComputer::map_logical_alias_to_physical_property_id()`, so there
should be no behaviour change.
Previously we would incorrectly map these in
`CSSStyleProperties::convert_declarations_to_specified_order`, aside
from being too early (as it meant we didn't maintain them as distinct
from their physical counterparts in CSSStyleProperties), this meant
that we didn't yet have the required context to map them correctly.
We now map them as part of the cascade process. To compute the mapping
context we do a cascade without mapping, and extract the relevant
properties (writing-direction and direction).
The "longhands" array is populated in the code generator to avoid the
overhead of manually maintaining the list in Properties.json
There is one subtest that still fails in
'cssstyledeclaration-csstext-all-shorthand', this is related to
us not maintaining the relative order of CSS declarations for custom vs
non-custom properties.
ParsedFontFace and FontLoader now both keep track of which
CSSStyleSheet (if any) was the source of the font-face, so the URLs can
be completed correctly.
Convert FontLoader to use fetch_a_style_resource(). ResourceLoader used
to keep its downloaded data around for us, but fetch doesn't, so we use
Gfx::Typeface::try_load_from_temporary_memory() so that the font has a
permanent copy of that data.
We achieve this by keeping track of all checked pseudo class selectors
in the SelectorEngine code. We also give StyleComputer per-pseudo-class
rule caches.
To prepare for introducing a CSS::URL type, we need to qualify any use
of LibURL as `::URL::foo` instead of `URL::foo` so the compiler doesn't
get confused.
Many of these uses will be replaced, but I don't want to mix this in
with what will likely already be a large change.
