Keep the non-subject :has() affected bit across element style
recomputation. This bit can be discovered while matching descendant
selectors, and recomputing the anchor itself may not revisit those
selectors before a later mutation needs the dependency for targeted
:has() invalidation.
This avoids stale descendant style after targeted :has() invalidation
when a previous recompute cleared the anchor-side dependency metadata.
Repeated style invalidation tests cover the previously flaky case.
Remove the PropertyNameAndID::from_name overload that accepted
FlyString. Parser declarations still store their token names as
FlyString, but the conversion to UTF-16 now happens explicitly at those
boundaries.
Move PropertyNameAndID, custom property data, registered custom
properties, and Typed OM associated property names to Utf16FlyString.
This removes the FlyString storage boundary from CSS property-name
handling and lets CSSStyleProperties keep the name it receives from
CSSOM instead of converting it back to UTF-8.
When an element was affected by :has() in subject position,
pending :has() mutation invalidation also applied the pseudo-class
invalidation plan for that element. If the same element had ever been
observed in a non-subject :has() selector, that plan could invalidate
the element's whole descendant subtree even when the mutation could
only require the subject element itself to recompute style.
Keep subject-position :has() invalidation to the element itself, and
run the descendant fanout only for non-subject involvement after the
existing mutation feature filter says that fanout may be affected.
Track the strongest invalidation applied to each anchor, so a later
batched mutation can still upgrade earlier anchor-only work to a
descendant fanout.
Extend the filter to treat known state pseudo-classes as concrete
mutation features, so a :hover mutation does not conservatively match
unrelated selectors such as :has(dialog:modal).
Scope boundary selectors are kept conservative where needed: when an
@scope boundary contains :has(), the scope root's match can activate or
deactivate style rules for descendants, so it still records descendant
involvement.
Add coverage for unrelated hover and batched mutation cases on elements
whose ancestors have both subject and non-subject :has() involvement,
ensuring descendant no-op recomputation stays bounded without dropping
required descendant fanout.
Move ComputedProperties and CascadedProperties out of the GC. They no
longer contain strong references to GC-managed data.
Keep computed styles alive from DOM elements and animation updates with
RefPtr. Pass style into layout constructors by reference, since layout
only copies the values it needs while building nodes.
Use GC::Weak for cascade source links, so entries no longer keep the
style declaration or shadow root alive.
UA and user stylesheets do not have owner nodes or owner rules, so their
matched rules cannot be mapped through the generic stylesheet identifier
helper. Share the built-in UA stylesheet enumeration and map UA rules by
the matched CSSStyleSheet object, so that they stay in sync with any
future changes.
Include parser rule locations and stylesheet identities in the applied
style rule data sent to DevTools. This gives the protocol layer enough
information to map matched rules to existing stylesheet resources
without guessing from displayed rule text.
Collect the style rules that apply to an inspected element and expose
them through the existing DOM node inspection path. This gives Firefox's
Rules panel real rule forms instead of the previous empty getApplied
response.
Treat a scoped `@import` rule as a scope descriptor while traversing
style-producing rules from imported stylesheets. Imported rules now
inherit an outer scope for unscoped imports and replace it when the
import itself carries scope(...).
Scope resolution was generalized to handle both CSSScopeRule and
CSSImportRule descriptors. Import-scope boundaries are matched using
the stylesheet that parsed the `@import` rule, while normal imported
selectors keep using the imported stylesheet context. This lets
implicit scopes, nested `@scope` rules, :scope, and top-level `&` behave
as the Cascade 6 model requires.
Enable -Wexit-time-destructors for all in-tree library targets and
update process-lifetime library statics so they no longer register
exit-time destructors. Long-lived caches, lookup tables, singleton
registries, and generated constants now use NeverDestroyed or leaked
references where the data is intended to live until process exit.
Update LibWeb, LibLine, and the binding generators so regenerated
sources follow the same rule instead of reintroducing destructed
statics.
Skip starting CSS transitions when the document timeline has no current
time yet. Focus can force a style update from a requestAnimationFrame
callback before the rendering step updates animation timelines, leaving
the DocumentTimeline current time unresolved.
Add crash coverage for a focus-triggered transition from a frame
callback.
Scoped rules depend on their `@scope` start and end selectors, not just
the selectors for the declarations inside the rule. Register those
boundary selectors in the style invalidation data and selector insights
so mutations that create or remove scope roots or limits invalidate
descendant styles that may now match differently.
Scope boundary matching also needs to record selector involvement
against the element being styled. That keeps :has(), sibling, and
structural selector invalidation from treating the boundary candidate
as the only affected subject.
Run the stored :has() invalidation plans for affected anchors as well
as marking subject anchors dirty. This lets scope-boundary :has()
changes invalidate scoped descendants instead of leaving stale styles.
Add cqw/cqh/cqi/cqb/cqmin/cqmax to the unit tables and generated
helpers, then thread them through the shared length resolution path.
Length::ResolutionContext now carries the subject element and whether
its inline axis is horizontal. Container units need that extra context:
the nearest eligible query container is selected from the subject
element's flat-tree ancestors, and cqi/cqb/cqmin/cqmax map logical axes
through the subject's writing mode before resolving to a physical width
or height.
Teach Length to resolve each axis against the selected container's
content box, fall back to viewport lengths when no eligible container
exists, and mark size-container dependencies so post-layout
recomputation can happen when layout is not up to date.
Also expose the new units through Typed OM, reject them for
computationally independent `@property` initial values, and add focused
font-size coverage.
Apply author declarations in encapsulation-context order before layer,
specificity, scope proximity, and source-order tie breaking. Normal
author rules now cascade from inner shadow contexts outward. This lets
outer contexts override component defaults. Important author rules
cascade the other way so inner contexts can enforce requirements.
Keep the ordering context-bucketed. The common document-only path still
collects and sorts one author context. Custom properties follow the same
context order. var() substitution now observes the same winners as
longhand properties.
Make revert-layer remove declarations only from the matching cascade
origin, context, and layer. This keeps presentational hints and values
from other shadow contexts available when one context rolls back its own
layer.
Add coverage for document and shadow-host competition, slotted rules,
nested slot contexts, inline styles, important declarations, custom
properties, and revert-layer across shadow contexts.
Keep the temporary scoped matching rule list on StyleComputer.
This lets repeated style matching reuse its allocation instead of
creating a large stack object in collect_matching_rules().
Release builds zero that stack object before the constructor runs due
to automatic variable initialization. This was causing a 16 KiB memset
on every call to this function(!)
Verify that the scratch vector is empty on entry so accidental reentry
is caught before it can corrupt the outer rule collection.
Resolve prelude-less @scope roots from the owning stylesheet context
during matching. This lets implicit scoped declarations target a style
element's parent. It also lets implicit shadow-root scopes use the
shadow host as the scoping root.
Use StyleValue's computational-independence predicate when deciding
which specified values to retain for inherited-style recomputation.
Compound values such as shadows, filters, lists, and calc trees now
reuse their existing dependency tracking instead of the old bare-length
check.
Treat missing tuple entries and keyword-only edge offsets as
computationally independent. These nullable slots are part of the
parsed value representation, and the inherited dependency tracking now
uses the shared computational-independence query for specified values.
Add viewport resize coverage for media query changes that update root
font metrics while a descendant uses font-relative lengths inside
box-shadow and filter values.
Record when computed properties depend on viewport metrics while
resolving lengths. Carry that information through font metrics so
font-relative lengths can be associated with viewport-sized fonts.
This keeps the dependency tracking local to style computation and gives
later viewport resize invalidation a way to find affected elements.
`@scope (a) to (b) {}` applies its contained style rules to elements
that have `a` as a parent, and do not have `a b` as a parent. Both the
`a` and `b` selector lists are optional.
Because it's situational whether a `@scope` will apply to a given
element, we store the ancestor scope on the `MatchingRule`, similar to
`@container`, and then determine during matching whether all the parent
`@scope`s match or not.
The rules for how selectors inside `@scope` are adjusted and interpreted
are a bit confusing. Unlike for other at-rules, nested style rules
inside `@scope` do not get a leading `&` added during parsing. To
support this, `adapt_nested_relative_selector_list()` now takes a flag
for whether its parent is a `@scope` or not.
`@scope` can also contain nested declarations without itself being
nested inside a style rule.
When determining their selectors, nested declarations rules adopt the
`@scope`'s scoping root if it has one, or otherwise fall back to the
parent element of the `<style>` element (not implemented here,) or the
`:root`. These are required to have zero specificity, so we wrap the
selector in `:where()`.
This is preparation for nested declarations inside `@scope`. User code
no longer makes assumptions about there being a style rule parent, as
there may not be one.
We cache the absolutized selectors because `@scope` will require us to
modify the parent's selectors instead of using them directly.
Track explicit inherit of non-inherited properties only on the direct
parent shadow root. A deeper descendant with margin-left: inherit still
inherits from its own parent, so a host margin change does not require
marking every ancestor as possibly affected.
Extend the shadow-root inherited style test to cover both the direct
child case that must still update and the deeper descendant case that
must not trigger broad inherited-style recomputation.
Track when style recomputation may require inherited-style work in a
shadow tree, and use that signal when crossing from a shadow host into
its shadow root. Shadow descendants can explicitly inherit normally
non-inherited host properties, so any host style change may need
inherited-style recomputation there.
Use the CSS property definition to tell whether changed longhands need
to propagate to shadow descendants. Do the same after recomputing
inheritance-dependent values, such as host font-size: 2em after a parent
font-size change.
The shadow DOM tests cover inline and class-driven inherited host style
changes, explicit inherit for non-inherited host properties, relative
units on hosts, and nested slotted inheritance updates.
Previously we applied them ad-hoc when computing the style for the
referenced element but we now apply it as part of the cascade. This
fixes a couple bugs:
- Computing the style for the pseudo-element (rather than the
referenced element itself) as we do in the case we don't have a
layout node in `get_direct_property` now includes the inline style.
- Inline style is applied according to the cascade (i.e. it can be
overriden by non-inline `!important` styles).
- Properties go through the computation process.
e.g., `@container (width >= 300px) {}` and similar.
During style computation, flag any elements whose style depends on a
size container. Then re-evaluate their style after the initial layout
has been computed and size containers have a size. This may take
multiple passes, as these may have further descendants that depend on
their size, etc. We limit this to 8 passes currently.
SizeFeature itself is very similar to MediaFeature, but queries the
container element instead. There are only 6 size features specified, so
they're hard-coded instead of generated from JSON.
Also add a counter test for the narrower restyle path.
We now apply first letter styles by splitting text with a first-letter
style applied into 2 `TextSliceNode` objects. The
`DOM::Text` layout node always points at the non first-letter slice
and the first-letter slice is reachable via
`TextSliceNode::first_letter_slice()`.
First letter splitting works by `TreeBuilder` walking a block
container's inline descendants to find the first typographic letter
unit per the pattern given in css-pseudo level 4, which is then
wrapped in an anonymous inline box styled with the `::first-letter`
computed properties.
Consumers that map between DOM offsets and layout geometry
are updated to visit all slices of a `DOM::Text` through
`TextOffsetMapping`.
MatchingRules now have a container_rule member which stores the nearest
ancestor CSSContainerRule, if any. When populating the rule cache, we
maintain a stack of CSSContainerRules that we are within, and use
record the last one on the MatchingRule, so that it's O(1) instead of
having to walk up the rule's ancestors each time. This does mean we
have reimplement some "for each rule" code.
When collecting rules to apply to an element, we see if the MatchingRule
has a container_rule, and if so, we evaluate that rule's query to see
if the element has a matching container. We then also match any ancestor
container rules, using the cached parent container rule.
Add a custom test to cover the case of nested name-only `@container`s,
which WPT lacks currently as far as I can tell.
Previously, and according to the spec, `a::part(foo)::before` would be a
single CompoundSelector, even though it matches against 3 different
targets. This meant some awkward swapping of targets in the middle of
matching, and in particular it made `::part()` and `::slotted()` quite
hacky, requiring them to track extra data on the MatchContext to then
use later. This was scattered around and difficult to follow.
Partly inspired by Gecko, this commit instead introduces an invisible
PseudoElement combinator. After parsing a selector, we find any
CompoundSelectors that contain a pseudo-element and split them up, so
that each CompoundSelector only has a single target in the end. Where
the pseudo-element was at the start of a CompoundSelector, we insert an
invisible universal selector before it to represent its originating
element.
So now, a CompoundSelector deals with one target, and switching targets
is done at the combinator.
The one inconsistency is that we match the target of ::slotted()
and ::part() in pseudo_element_transition_target(), instead of before
then when processing the SimpleSelector. This is to avoid repeating the
same computations twice.
No outward-facing behaviour changes, though the invalidation metrics
have changed.
Previously we were inconsistent by generating code for enum definitions
but not generating code for dictionaries. With future changes to the
IDL generator to expose helpers to convert to and from IDL values
this produced circular depdendencies. To solve this problem, also
generate the dictionary definitions in bindings headers.
Previously, we consulted `cascaded_properties()` in a couple of places
after the cascade pass for the relevant element had finished, forcing
`CascadedProperties` to outlive style resolution.
We now keep the small set of values these consumers need on
`ComputedProperties`. We keep hold of resolved specified values for
properties whose computation depends on inherited info, so they can be
re-resolved when an ancestor changes. We also keep the raw winning
cascaded font-size, as this is needed by the time-traveling monospace
font quirk implemented by `recascade_font_size_if_needed()`.
Previously, presentational hints bypassed the regular cascade pipeline
and wrote directly into `CascadedProperties` under
`CascadeOrigin::Author`. That meant `var()` substitution and the
invalid-at-computed-value-time fallback had to be duplicated in a
separate per-element pass, which in practice missed the IACVT step and
could leave a `GuaranteedInvalidStyleValue` in the cascaded
properties. This caused a crash in downstream code that assumed the
value had been resolved.
This introduces an `AuthorPresentationalHint` cascade origin and feeds
them through the cascade as normal declarations. This means that
`var()` resolution now happens in only one place.
This is preparatory work for routing presentational hints through the
same cascade pipeline as ordinary CSS declarations. Currently those
hints bypass `cascade_declarations()` and write into
`CascadedProperties` directly, which means `var()` substitution has to
be duplicated in a separate pass. To unify them at a single point, we
need to be able to feed an arbitrary property list.
Per "find flattened slotables", a <slot> whose root is a shadow root is
recursed through, not appended to the result. ::slotted() in an outer
shadow must therefore not match such an intermediate slot.
Fixes the gallery on Reddit comment pages: a re-slotted <slot> was
picking up `::slotted(:not([slot])) { display: grid }` from the inner
shadow, which made the <ul> size to its content rather than the flex
container, leaving the carousel's "next" button with a 0px translate.
Share the style cache for shadow roots whose only active author sheet is
the same constructed stylesheet. Matching already carries the effective
shadow root separately, so the cache can be reused while selectors such
as :host and ::slotted() still evaluate against each consuming shadow
root.
Keep the optimization conservative by falling back to the existing
per-scope cache whenever the shadow root has multiple active sheets, a
non-constructed sheet, or a page user stylesheet. Drop the shared cache
when the stylesheet rules or media query match state change.
Add coverage for two shadow roots adopting the same constructed sheet,
including :host, ::slotted(), and replaceSync() invalidation.
Keep cached MatchingRule entries independent from the shadow root that
owns the rule cache. Thread the effective rule shadow root through style
matching as transient state instead, so a rule cache can later be shared
by multiple scopes without copying every cached rule.
This preserves the existing matching behavior by deriving the effective
rule root from each cache lookup site. Pseudo-class invalidation already
operates on a single style scope, so it no longer needs a per-rule scope
filter.
When computing pseudo-element style and no pseudo-element rules match,
StyleComputer was returning early without clearing the cascaded and
custom property data on the AbstractElement. As a result,
getComputedStyle() on the pseudo-element kept exposing values from a
previous matching state.
Clear both before bailing so a transition from matched to unmatched
leaves the pseudo-element in a clean state.
Previously, we were accidentally creating temporary copies of custom
property maps on both sides of a ternary in `compute_style_impl()`. We
now bind to a static empty sentinel instead so the reference binds
directly to `own_values()` without copying.
When inheriting custom-property data from a parent element, we were
copying the parent's full CustomPropertyData regardless of whether
each property was registered with `inherits: false`. That caused
non-inheriting registered properties to leak from the parent,
contrary to the @property spec.
Wrap the parent-side lookup so we strip any custom property whose
registration says it should not inherit, and only build a fresh
CustomPropertyData when at least one property was actually filtered.
Key the filtered view's cache on both the destination document's
identity and its custom-property registration generation. The
generation counter is local to each document, so a subtree adopted
into another document (or queried via getComputedStyle from another
window) could otherwise pick up a cached view computed under an
unrelated registration set and silently skip non-inheriting filtering
in the new document.
A @keyframes rule scoped to a shadow root was not reliably reached
from an animated slotted light-DOM element: the keyframes lookup
walked the element's own root first, then fell back to the document,
but slotted elements can pick up animation-name from a ::slotted(...)
rule that lives in an ancestor shadow root rather than in the
element's own tree.
Track the shadow-root scope that supplied each winning cascaded
declaration, and use that scope to resolve the matching @keyframes
when processing animation definitions. A shared constructable
stylesheet can be adopted into several scopes at once, so the
declaration object alone is too weak as a key; the per-entry
shadow-root pointer disambiguates which adoption actually contributed.
Also refresh running CSS animations' keyframe sets when style is
recomputed. Previously only the first animation creation path set a
keyframe set, so an existing animation never picked up newly inserted
@keyframes rules.
This allows us to avoid the ugly hack in
`property_accepted_type_ranges()`.
This also updates the `ValueType` to be `opacity-value` rather than
`opacity` to match the spec.
Record per-feature :has() invalidation metadata instead of only tracking
whether some selector somewhere mentions a class, id, attribute, tag,
or pseudo-class. The new buckets preserve the relative selector and a
coarse scope classification for each :has() argument, which gives the
next invalidation step enough information to route mutations more
precisely.
Keep this commit behavior-preserving for mutation handling by only
switching the lookup path over to the new metadata buckets. Expose a
test-only counter for the number of candidate :has() metadata entries a
mutation matched, and add coverage showing that one feature can map to
one or multiple :has() buckets without forcing a document-wide yes/no
answer.
sort_matching_rules() was calling Selector::specificity() inside the
sort comparator. MatchingRule already caches the specificity value
at rule insertion time, so use that directly instead.
This were introduced in dfe5d00 but only papered over the underlying
issue that we were computing style for element belonging to detached
documents - this underlying fix was implemented in c173a66 so these
fallbacks/guards are no longer needed
