Using a generic context argument will allow us to resolve colors in
places where we have all the required information but not in the form of
a layout node as was expected previously.
Now we pass all WPT tests in:
`css/css-properties-values-api/at-property-cssom`.
Note: Failing tests were false positives.
Proper handling of inheriting values and detecting computational
independence will be done in another PR.
QualifiedRule::for_each_as_declaration_list() now takes a rule_name, so
that the error message can actually be useful - we only know what a
qualified rule is by context.
Instead of random dbgln_if(CSS_PARSER_DEBUG) messages, this lets us
report what kind of error it was. Repeated errors are combined instead
of spamming the console.
Ideally this would also record where the error occurred, but not yet.
This parses `anchor-size(..)` functions in CSS, but does not yet result
in a useful `Size`: we need style & layout interleaving similar to
container queries for this, since the resulting value depends on layout
results.
Not supported yet: `anchor-size()` appearing inside a `calc()` node.
Adds 4280 WPT subtest passes in `css/css-anchor-position`.
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.
Compare `Vector<Parser::ComponentValue>` directly instead of
serializing them into strings first.
This is required for the upcoming changes where we would compare
previous and new sets of custom properties to figure out whether we need
to invalidate descendant elements. Without this change `equals()` would
show up being hot in profiles.
This uses a `foo>bar` notation in the `valid-identifiers` field of
Properties.json, to say "replace `foo` with `bar`".
The motivation here is to avoid calling `parse_css_value_for_property()`
inside the per-property switch in `parse_css_value()`. Eventually we'll
need to be able to call that switch from
`parse_css_value_for_properties()` so that shorthands can make use of
any bespoke parsing code to parse their longhands.
Before this change, calc() would resolve to different types depending on
the nearest containing value context. This meant that rgb(calc(), ...)
by itself worked correctly due to fallbacks, but rgb(calc(), ...) inside
e.g a linear-gradient would create a calc() value that resolves to a
length, which subsequently got rejected by the color value parser.
Fixing this makes various little gradients show up on Discord.
...for `text-justify: inter-character`.
We previously had this mapped in Enums.json, but the behaviour is
different: `a=b` in Enums.json keeps `a` around but makes it behave the
same as `b`. A legacy name alias is instead expected to replace `a`
with `b`, so we have to do that separately.
We don't yet have a system for "legacy value aliases", but until we have
a lot of them we can handle them manually.
We also have to do this in two places because
parse_css_value_for_property() doesn't call any property-specific
parsing code.
We now do the proper thing in terms of:
- Allowing percentages
- Returning the computed value in getComputedStyle
- Handling values out of the [0,1] range
Gains us 13 WPT passes in the imported tests.
Add global registry for registered properties and partial support
for `@property` rule. Enables registering properties with initial
values. Also adds basic retrieval via `var()`.
Note: This is not a complete `@property` implementation.
`<syntax>` is a limited subset of the "value definition syntax" used in
CSS specs. It's used for `@property`'s `syntax` descriptor, and for the
`type()` function in `attr()`.
UnresolvedStyleValue::create() has one user where we know if there are
any arbitrary substitution functions in the list of CVs, and two users
where we don't know and just hope there aren't any. I'm about to add
another user that also doesn't know, and so it seems worth just making
UnresolvedStyleValue::create() do that work instead.
We keep the parameter, now Optional<>, so that we save some redundant
work in that one place where we do already know.
The existing resolve methods are not to spec and we are working to
replace them with new ones based on the `simplify_a_calculation_tree`
method.
These are marked as deprecated rather than replaced outright as work
will need to be done on the caller side to be made compatible with the
new methods, for instance the new methods can fail to resolve (e.g.
if we are missing required context), where the existing methods will
always resolve (albeit sometimes with an incorrect value).
No functionality changes.
We were previously handling this ad-hoc via logic in
`get_property_internal` but this didn't cover all contexts (for
instance `CSSStyleProperties::serialized`.
Gains us 9 more WPT tests as we now cover properties which weren't
included in the previous ad-hoc approach.
Previously if we encountered a keyword other than `fill` when parsing
`<border-image-slice` we would return a nullptr.
This could cause issues when we parse `<border-image-slice>` as part of
parsing `border-image`, for example `border-image: 100% none` would fail
as we would try parse `none` as part of the `<border-image-slice>`
instead of `<border-image-source>`.
This change makes it so that we don't consume the token and leave it to
be parsed as part of the next section of the grammar.
The attack unfortunately still slows us down, but this prevents us from
OOMing. Currently, we don't save the value of `var(--foo)` after
computing it once, so in this example, we end up computing `--prop1` 4
times to compute `--prop3`, but then we start again from scratch when
computing `--prop4`:
```css
--prop1: lol;
--prop2: var(--prop1) var(--prop1);
--prop3: var(--prop2) var(--prop2);
--prop4: var(--prop3) var(--prop3);
}
```
This should be solvable later if we update the computed values as we go.
"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.
This has an extra parameter to allow stopping at the first comma token,
which we need for var() and attr()'s "argument grammar".
Co-authored-by: Tim Ledbetter <tim.ledbetter@ladybird.org>
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.
