An upcoming commit will migrate the contents of Headers.h/cpp to LibHTTP
for use outside of LibWeb. These CORS and MIME helpers depend on other
LibWeb facilities, however, so they cannot be moved.
Previously we would only update these if:
a) We had a cascaded value for `transition-property`
b) The source of that cascaded value had changed since we last
registered transitions
This meant that there were a lot of changes we didn't apply:
- Changes exclusively to properties other than `transition-property`
(e.g. `transition-duration`, `transition-behavior`, etc)
- Removing the `transition-property` property
- Updating the `transition-property` property in a way that didn't
change it's source (e.g. setting it within inline-style)
Unfortunately this does mean that we now register transitions for all
properties on most elements since "all" is the initial value for
"transition-property" which isn't great for performance, but that can be
looked at in later commits.
Also renames the `clear_transitions` function to clarify this doesn't
affect the associated transition animations.
This fixes an issue where transitions weren't being cancelled when the
relevant transition-property entry was no longer present
Before this change, we've been maintaining various StyleComputer caches
at the document level.
This made sense for old-school documents without shadow trees, since
all the style information was document-wide anyway. However, documents
with many shadow trees ended up suffering since any time you mutated
a style sheet inside a shadow tree, *all* style caches for the entire
document would get invalidated.
This was particularly expensive on Reddit, which has tons of shadow
trees with their own style elements. Every time we'd create one of their
custom elements, we'd invalidate the document-level "rule cache" and
have to rebuild it, taking about ~60ms each time (ouch).
This commit introduces a new object called StyleScope.
Every Document and ShadowRoot has its own StyleScope. Rule caches etc
are moved from StyleComputer to StyleScope.
Rule cache invalidation now happens at StyleScope level. As an example,
rule cache rebuilds now take ~1ms on Reddit instead of ~60ms.
This is largely a mechanical change, moving things around, but there's
one key detail to be aware of: due to the :host selector, which works
across the shadow DOM boundary and reaches from inside a shadow tree out
into the light tree, there are various places where we have to check
both the shadow tree's StyleScope *and* the document-level StyleScope
in order to get all rules that may apply.
The exception returned here is never used or logged. Let's just return
a null request, to make it clearer that these are not exceptions shown
to the user (thus not observable).
`play_or_cancel_animations_after_display_property_change` is called
whenever an element is inserted or removed, or it's display property
changes, but it is only required to run if we actually have animations
to play or cancel.
Reduces time spent in the aforementioned function from ~2% to ~0.03%
when loading https://en.wikipedia.org/wiki/2023_in_American_television
We don't need to iterate every property in start_needed_transitions,
only those that appear in transition-property or have an existing
transition
Reduces the time spent in start_needed_transitions from ~5% to ~0.03%
when loading https://en.wikipedia.org/wiki/2023_in_American_television
The majority of time in `compute_font()` was spent in
`font_matching_algorithm()` repeatedly computing the same values. We
now cache these values to avoid unnecessary work.
Makes the `compute_font_variation_settings` function match other
`compute_font_*` by absolutizing values passed into them. It resolves a
crash related to using `siblings-count` inside `font-variation-settings`
Co-authored-by: Sam Atkins <sam@ladybird.org>
Integrates the new `FontVariationSettings` from LibGfx into LibWeb to
enable initial variable font functionality. Currently, only the `wght`
(weight) axis is fully supported and tested. This update also introduces
support for the CSS `font-variation-settings` property.
There were a couple places that we had special handling for the `all`
property but since d31a58a was merged we can treat it the same as any
other shorthand
There are a few places in style computation where we want to update the
value of a property without modifying the inherited or important flags.
Previously we would look up these flags and pass them to the normal
`set_property` method but this is unnecessary and was easy to forget to
do.
We don't need all this specific logic for parsing the `transition`
property - we also now maintain `none` as such until use time which
gains us a couple extra tests
Unrecognized property names should still be kept in the list to preserve
matching of indices (e.g. that the Nth property should associate with
the Nth duration)
Since we now have access to the `AbstractElement` through the
`ComputationContext` we can just set the flag that this element relies
on tree counting functions directly, no need to pass this struct around.
Passing the `AbstractElement` rather than the
`TreeCountingFunctionResolutionContext` allows us to only compute the
resolution context when necessary (i.e. when we actually need to resolve
a tree counting function)
When we compute style for elements inside a UA-internal shadow tree that
represent a pseudo-element (e.g ::placeholder), we actually run the
StyleComputer machinery for (host element :: pseudo-element).
While that lets us match the correct selectors, it was incorrectly
applying CSS inheritance, since we'd also then inherit from whatever was
above the host element in the tree.
This patch fixes the issue by introducing an inheritance override in
AbstractElement and then using that to force inheritance from whatever
is actually directly above in the DOM for these elements instead of
jumping all the way up past the host.
This fixes an issue where `text-align: center` on input type=text
elements would render the main text centered but placeholder text was
still left-aligned.
Tree counting functions should be resolved at style computation time -
to do this we will need to know the element's sibling count and index.
This commit computes that information and propagates it to the various
`StyleValue::to_computed_value` methods.
This excludes `step-end` and `step-start` which are expected to be
converted to the equivalent function at parse time.
We are expected to serialize these as the explicit keywords - previously
we would parse as `EasingStyleValue` and serialize equivalent functions
as the keywords. This caused issues as we would incorrectly serialize
even explicit functions as the keyword.
This also allows us to move the magic easing functions to
`EasingFunction` rather than `EasingStyleValue` which is a bit tidier
This struct will in the future hold information other than a length
resolution context (e.g. context for tree counting functions) and a
single struct is easier to work with than multiple parameters.
This commit modifies the `compute_foo()` code for `font-style` and
`math-depth`. They previously assumed that their StyleValue was always
a special kind: FontStyleStyleValue or MathDepthStyleValue. This was
always true, because that's how we parse them, but it stops being true
once StylePropertyMap is involved: An author can set font-style to a
CSSKeywordValue of "italic", and this should work.
There are multiple ways that we could solve this, but the simplest and
easiest to maintain seems to be to handle those more basic StyleValues
in this computation code. Going forward, we'll have to be aware that
similar properties could have a basic StyleValue from the typed-OM
instead of the property-specific one we'd expect.
Whether an absbox is positioned below or to the right of its previous
sibling in an `InlineFormattingContext` is determined by the
display-outside value before blockification, so we store the
pre-blockification `display` value in `ComputedValues` to access it in
`InlineFormattingContext` and position the box accordingly.
Opacity values are unique in that the range which calculated and
interpolated values should be clamped to [0,1] is different from the
range of allowed values [-∞,∞].
This fixes 28 WPT tests that were regressed in #6112
We were unnecessarily computing property values within
`collect_animation_into` which we can avoid by ensuring that all calls
to `collect_animation_into` happen after property values are computed.
We now fail a few more tests in properties-value-inherit-001.txt as we
no longer overwrite the non-animated value of `line-height` with the
animated value, this is in line with other major browsers.
We were already doing this within `compute_property_values` where
we resolved most relative lengths but the remainder was instead
incorrectly using the font's line-spacing
Previously if we would overwrite the non-animated font-size with the
animated font-size if it was set.
Loses us 2 WPT tests but this is in line with other browsers
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.
Remaining test failures in font-size-interpolation-00* are either:
- Rounding of font-size to CSSPixels when setting the expected value
- Not clamping negative values from the point of view of
getComputedStyle (used values are still clamped)
Previously if we would overwrite the non-animated font-size with the
animated font-size if it was set.
Gains us 8 WPT tests and means we now fail 9 others in line with other
browsers.
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.
A new parameter was added to Web::CSS::StyleValue::to_string() in
PR #2820 but this debug message was never updated. If
CSS_TRANSITIONS_DEBUG was enabled, compilation would fail.
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.
Transitions apply after logical properties are mapped to their physical
counterparts so we should apply this mapping to `transition` properties
Gains us 20 WPT tests.
Using longhands rather than expanded longhands meant for instance that
we wouldn't transition `border-top-width` if we had `border` as the
transition property.
Continues the work started in #5386 to simplify handling of positional
value list shorthand properties.
Previously we would parse these as `StyleValueList`s and then rely on
`StyleComputer::for_each_property_expanding_shorthands` to expand them
into longhands.
This required a bit of work to handle `ShorthandStyleValue`s for the
`@page` `margin` descriptor.
Implements `::slotted()` to enough extent we could pass the imported WPT
test and make substantial layout correctness improvement on
https://www.rottentomatoes.com/
`font-size` can end up with a negative value - either due to `calc`
being resolved using the old method which doesn't clamp the value, or
interpolation - in this case we should clamp negative values to zero.
Gains us 36 new WPT passes and fixes crashes in the three imported
tests.
We now also store `outline-width` in ComputedValues as a `CSSPixels`
since we know it's an absolute length at `apply_style` time - this saves
us some work in converting to CSSPixels during layout.
Gains us 46 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).
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`.
`StyleComputer::create_document_style` was the only place this wasn't
the case so we can remove the calls to
`compute_defaulted_property_value`. The call to
`compute_defaulted_values` in `create_document_style` is now redundant
so has been removed`
This was the last thing that `compute_defaulted_values` was doing when
called from here.
It also comes with the added benefit of us correctly inheriting animated
colors.
As `recompute_inherited_style` works in-place rather than building
ComputedProperties from scratch we need to keep track of which animated
properties are inherited to know whether we should remove them when we
have no more inherited value.
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 commit updates the CSSTransition constructor to:
- Leave the KeyframeEffect start time unresolved
- Set the KeyframeEffect start delay
Gains us 14 WPT passes but exposes one false positive in
properties-value-inherit-001.html
Flex/grid items are always blockified (have their CSS display forced
into "block") by style computation.
We were doing this by looking at the CSS display of the parent. However,
if the parent has `display: contents`, we must look at the *grandparent*
instead.
This corrects the layout of buttons underneath Reddit article cards.
When a subtree is projected through a slot, its root now inherits style
from the slot's parent, rather than the parent of the unprojected root.
This fixes a ton of subtle issues, and is very noticeable on Reddit.
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 `""`.