The HTML sizes algorithm does not use full media queries. It evaluates
a restricted media-condition grammar and then parses the selected
source size value as a length.
Teach the parser to follow that split more closely: treat sizes
conditions as two-valued booleans, validate MQ5 <general-enclosed>
contents more strictly, accept calc(0) for media feature values, and
reject only source-size math results that are negative or non-finite.
The imported sizes parsing tests then progress from 140/171 to
171/171 in all four cases.
This correctly rejects invalid trailing tokens from `anchor()` fallback
values. Also introduces discard_whitespace() to take care of any
whitespace between the fallback value and the closing parenthesis.
We now ignore all animation properties from `css-animations-1` declared
within keyframes, except `animation-timing-function`, which is treated
specially.
There was only one place that we weren't passing this where we could
have ASFs so let's just handle that there and explicitly mark the others
as having no ASFs to avoid unnecessary work.
No functional changes
`@function` descriptors are the only ones that support ASFs, while most
descriptors enforce this through their syntaxes implicitly disallowing
ASFs, this wasn't the case for `@property/initial-value`.
We now explictly disallow ASFs unless they are marked as allowed within
`Descriptors.json`.
Everywhere we use this expects us to parse the whole value, either
because we are parsing the value of a declaration (in which case there
will be no semicolons), or because it is called from a JS setter which
takes whole values and semicolons make the value invalid.
Previously we would just ignore everything after a semicolon.
This also allows us to avoid creating a new `Vector` and copying all the
component values
Allow CSS pseudo-element chaining with ::part() so that
selectors like ::part(title)::before can style pseudo-elements
within shadow DOM parts.
Parser changes (SelectorParsing.cpp): The pseudo-element
validation logic now tracks which pseudo-element appears first
and second in a compound selector. When multiple pseudo-elements
are found, the parser permits the selector only if the first is
::part() and the second is NOT ::part(). A maximum of two
pseudo-elements is enforced.
Selector changes (Selector.cpp, Selector.h): The Selector
constructor now stores the last pseudo-element (the styling
target) rather than the first. For ::part(foo)::before, the
selector reports ::before as its target. A new
m_contains_part_pseudo_element flag separately tracks whether
::part() is present for the selector engine.
Fixes 9 WPT tests: 6 in css/selectors/parsing/parse-part.html
for chained selector parsing, and 3 in
css/css-shadow-parts/multiple-scopes.html for correct scoping
of exported, middle-scope, and non-exported part selectors.
The main limitation here are that none of the container-query features
are parsed in a meaningful way; they all become `<general-enclosed>`.
Parsing for them will be added as they are implemented.
No parsing yet, just CSSContainerRule and the supporting ContainerQuery
class.
CSSContainerRule is unusual in how it matches, because instead of it
either matching or not matching globally, it instead is matched against
a specific element. But also, some at-rules inside it always apply, as
if they were written outside it. This doesn't fit well with how
CSSConditionRule is implemented, and will likely require some rework
later. For now, `condition_matches()` always returns false, and
`for_each_effective_rule()` is overridden to always process those
global at-rules and nothing else.
When parsing declarations within a nested grouping rule, we don't store
these directly, but within a "nested declarations rule", in most cases
this is `CSSNestedDeclarations`, but this isn't always the case e.g.
`@function` rules and others (e.g. @media) within them should instead
use `CSSFunctionDeclarations`
Some at-rules (i.e. `@function`) require us to support custom
descriptors (e.g. `--foo`).
We do this by adding `DescriptorID::Custom` and using a new
`DescriptorNameAndID` class in a bunch of places where we previously
just used `DescriptorID`
Currently this only applies to the `@property` `syntax` descriptor.
As with custom properties in the previous commit we assumed that any
consumed values were valid but that's not the case.
The definition of syntax in the "css-properties-values-api" spec (which
is used for the `@property/syntax` descriptor) is slightly different
from the definition of `<syntax>` in the "css-values" spec (which we
implement) in that it limits literal idents to exclusively
`<custom-ident>`s (i.e. not CSS-wide keywords or "default").
`<custom-ident>`s are also case-sensitive so that behavior is
implemented for syntax matching here as well
Previously we would consider an alternative syntax child to be a match
as long as parsing produced a value, even if there were trailing tokens
(which would later invalidate it within `parse_with_a_syntax`). This
meant that we wouldn't consider later alternatives which may actually
produce a valid match.
We no longer try to resolve calculated values at parse time which means
we support relative lengths.
We now clamp negative values rather than rejecting them at parse time.
Parsing has been inlined into `parse_ratio_value` and `parse_ratio` has
been removed since `parse_ratio_value` was the only caller
When parsing block contents, the CSS parser speculatively tries to parse
each item as a declaration first. If that fails, it restores the token
position and tries again as a qualified rule. This means every qualified
rule inside an at-rule block (e.g. @layer, @media) gets parsed twice:
once as a failed declaration (which consumes all tokens via
consume_the_remnants_of_a_bad_declaration), and then again successfully
as a rule.
Add a lookahead that checks for the `ident whitespace* ':'` pattern
before attempting declaration parsing. Since declarations must start
with this pattern per spec, we can skip the attempt entirely when it
doesn't match and go straight to qualified rule parsing.
This is a massive win on large Tailwind CSS stylesheets (like the one
used by chatgpt.com) where thousands of rules inside @layer blocks were
being double-parsed. On a 1.2MB Tailwind v4 stylesheet, parse time goes
from ~2000ms to ~95ms (21x speedup).
When a var() fallback value contained trailing whitespace (e.g.
`var(--foo, flex )`), parse_display_value() miscounted the tokens.
The remaining_token_count() check included whitespace tokens, routing
single-keyword values like "flex" to the multi-component path. The
multi-component parser then failed when encountering the trailing
whitespace token.
Fix this by counting only non-whitespace tokens for the single vs
multi-component routing decision, and by skipping whitespace in the
multi-component parsing loop.
See previous commit for details
We now support parsing of `display-p3-linear` (although it just falls
back to using Oklab since Skia doesn't support it)
Previously we had two implementations for parsing
`<color-interpolation-method>`, one for gradients and one for
`color-mix()` - this commit adds another which will unify the existing
ones in following commits.
This implementation has a couple of advantages over the existing ones:
- It is simpler in that it uses global CSS enums and their helper
functions
- It is spec compliant (unlike the `color-mix()` one which allows
arbitrary idents)
- It parses as a `StyleValue` which will be required once we support
`<custom-color-space>` since that can be an `ident()` which isn't
resolvable at parse time
