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 `""`.
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.)
...elements. Adds missing pseudo-element type passed into computed
properties getter.
Previously, due to this bug, we were using the element's computed
properties as the previous computed properties for its pseudo-elements.
This caused an excessive number of unintended CSS transitions to run.
The issue was particularly noticeable in Discord's emoji picker, where
each emoji has `::after` pseudo-element. We were incorrectly triggering
transitions on all their properties, resulting in significant
unnecessary work in style computation and animation event dispatching.
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.
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.
Make sure we have a parent element before trying to look at it!
I've also pulled out a stub function for getting a custom property's
initial value, so that there's only one place to change once we support
`@property` more.
Because we defined `th { text-align: center }` in our UA stylesheet, it
received a higher precedence than inherited (inline) styles. Firefox
deals with this by defining a custom `text-align` value that prioritizes
any inherited value before defaulting to `text-align: center`.
We now do this as well :^)
"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.
Before this change, we would never apply CSS rules where the selector
had a mixed-case tag name. This happened because our rule caches would
key them on the lowercased tag name, but we didn't lowercase the tag
name when fetching things from the cache.
This uncovered the fact that the SVG2 spec has a bunch of style applied
to non-rendered elements in a way that doesn't match other browsers.
Instead of blindly following the spec, we now match other browsers.
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).
As conflict resolution depends on whether the property was set directly
or via a shorthand, we have to store the non-expanded values in the
resolved keyframe properties.
When we have an unresolved value for a shorthand (e.g. `border-style:
var(--border-style)`, `keyframe_values` will contain an
`UnresolvedStyleValue` for the shorthand and
`PendingSubstitutionStyleValue`s for each of it's longhands.
When we come across the shorthand's `UnresolvedStyleValue` we will
resolve the value and set all of the relevant longhands.
If the longhand's `PendingSubstitutionStyleValue` was processed after
(which isn't always the case as the iteration order depends on a
HashMap) would overwrite the correctly resolved longhand.
To avoid this we just skip any `PendingSubstitutionStyleValue`s we come
across and rely on the resolution of the shorthand to set those
properties.
Resolves a crash @tcl3 was experiencing when adding a new
"border-image-repeat" property.
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.
This function is bogus, but it's still getting called a lot during media
query evaluation, so let's at least cache the font instead of recreating
it every single time.
We already had all necessary things for pseudo elements support in place
except ability to save transition properties in Animatable. This commit
adds the missing part.
`start_needed_transitions()` decides which animations need to be started
based on previous and current style property values. Before this change,
we were using the style value without animations applied as the
"current" value. This caused issues such as starting a new transition
from the animation’s end value when an ongoing animation was
interrupted.
If a property is uses discrete interpolation and TransitionBehavior is
not set to `AllowDiscrete` that property should be non-transitionable.
This is now true for properties whose animation type is not discrete,
but the animation type falls back to discrete.
This is a bit under-specced, specifically there's no definition of
CSSMarginDescriptors so I've gone with CSSStyleProperties for now. Gets
us 17 WPT subtests.
Previously, we would just assign the UnresolvedStyleValue to each
longhand, which was completely wrong but happened to work if it was a
ShorthandStyleValue (because that's basically a list of "set property X
to Y", and doesn't care which property it's the value of).
For example, the included `var-in-margin-shorthand.html` test would:
1. Set `margin-top` to `var(--a) 10px`
2. Resolve it to `margin-top: 5px 10px`
3. Reject that as invalid
What now happens is:
1. Set `margin-top` to a PendingSubstitutionValue
2. Resolve `margin` to `5px 10px`
3. Expand that out into its longhands
4. `margin-top` is `5px` 🎉
In order to support this, `for_each_property_expanding_shorthands()` now
runs the callback for the shorthand too if it's an unresolved or
pending-substitution value. This is so that we can store those in the
CascadedProperties until they can be resolved - otherwise, by the time
we want to resolve them, we don't have them any more.
`cascade_declarations()` has an unfortunate hack: it tracks, for each
declaration, which properties have already been given values, so that
it can avoid overwriting an actual value with a pending one. This is
necessary because of the unfortunate way that CSSStyleProperties holds
expanded longhands, and not just the original declarations. The spec
disagrees with itself about this, but we do need to do that expansion
for `element.style` to work correctly. This HashTable is unfortunate
but it does solve the problem until a better solution can be found.
If `value` was UnresolvedStyleValue, we'd attempt to `set_property...()`
with its resolved value, then call that again with the original
UnresolvedStyleValue. For any other kind of `value`, we'd simply call
call `set_property...()` twice with the same parameters.
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.
Typeface::try_load_from_externally_owned_memory() relies on that
external owner keeping the memory around. However, neither WOFF nor
WOFF2 do so - they both create separate ByteBuffers to hold the TTF
data. So, rename them to make it clearer that they don't have any
requirements on the byte owner.
Previously, if a transition property was not wrapped in a list, it
would be replaced with the default value in
`StyleComputer::compute_transitioned_properties`.
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.
This is used for default UA style right now, and we'll expand its use in
the near future.
Note that this required teaching the CSS parser to handle url()
functions when there's no document URL to resolve them against. If we
don't handle that, namespace rules in UA style don't parse correctly.
Quite simply, ignore any declarations for properties we don't want,
while computing a pseudo-element's style.
I've imported a WPT test for this, which fails without this patch.
The upcoming generated types will match those for pseudo-classes: A
PseudoElementSelector type, that then holds a PseudoElement enum
defining what it is. That enum will be at the top level in the Web::CSS
namespace.
In order to keep the diffs clearer, this commit renames and moves the
types, and then a following one will replace the handwritten enum with
a generated one.
We previously had PropertyOwningCSSStyleDeclaration and
ResolvedCSSStyleDeclaration, representing the current style properties
and resolved style respectively. Both of these were the
CSSStyleDeclaration type in the CSSOM. (We also had
ElementInlineCSSStyleDeclaration but I removed that in a previous
commit.)
In the meantime, the spec has changed so that these should now be a new
CSSStyleProperties type in the CSSOM. Also, we need to subclass
CSSStyleDeclaration for things like CSSFontFaceRule's list of
descriptors, which means it wouldn't hold style properties.
So, this commit does the fairly messy work of combining these two types
into a new CSSStyleProperties class. A lot of what previously was done
as separate methods in the two classes, now follows the spec steps of
"if the readonly flag is set, do X" instead, which is hopefully easier
to follow too.
There is still some functionality in CSSStyleDeclaration that belongs in
CSSStyleProperties, but I'll do that next. To avoid a huge diff for
"CSSStyleDeclaration-all-supported-properties-and-default-values.txt"
both here and in the following commit, we don't apply the (currently
empty) CSSStyleProperties prototype yet.
A font-size with rem units need to resolve against the default font
metrics for the root element, otherwise every time we compute style,
the reference value for rem units grows.
This fixes an issue where text on some web pages would grow every time
there was a relayout. This was very noticeable on https://proton.me/Fixes#339
We already have logic to play or cancel animations in an element's
subtree when the display property changes to or from none. However,
this was not sufficient to cover the case when an element starts/stops
being nested in display none after insertion.
When setting `font-family: monospace;` in CSS, we have to interpret
the keyword font sizes (small, medium, large, etc) as slightly smaller
for historical reasons. Normally the medium font size is 16px, but
for monospace it's 13px.
The way this needs to behave is extremely strange:
When encountering `font-family: monospace`, we have to go back and
replay the CSS cascade as if the medium font size had been 13px all
along. Otherwise relative values like 2em/200%/etc could have gotten
lost in the inheritance chain.
We implement this in a fairly naive way by explicitly checking for
`font-family: monospace` (note: it has to be *exactly* like that,
it can't be `font-family: monospace, Courier` or similar.)
When encountered, we simply walk the element ancestors and re-run the
cascade for the font-size property. This is clumsy and inefficient,
but it does work for the common cases.
Other browsers do more elaborate things that we should eventually care
about as well, such as user-configurable font settings, per-language
behavior, etc. For now, this is just something that allows us to handle
more WPT tests where things fall apart due to unexpected font sizes.
To learn more about the wonders of font-size, see this blog post:
https://manishearth.github.io/blog/2017/08/10/font-size-an-unexpectedly-complex-css-property/
This reduces the number of `.cpp` files that need to be recompiled when
one of the below header files changes as follows:
CSS/ComputedProperties.h: 1113 -> 49
CSS/ComputedValues.h: 1120 -> 209
Analysis of selectors on modern websites shows that the `:hover`
pseudo-class is mostly used in the subject position within relatively
simple selectors like `.a:hover`. This suggests that we could greatly
benefit from segregating them by id/class/tag name, this way reducing
number of selectors tested during hover style invalidation.
With this change, hover invalidation on Discord goes down from 70ms to
3ms on my machine. I also tested GMail and GitHub where this change
shows nice 2x-3x speedup.
If selector does not have any descendant combinators then we know for
sure it won't be filtered out by ancestor filter, which means there is
no need to check for it.
This change makes hover style invalidation go faster on Discord where
with this change we spend 4-5% in `should_reject_with_ancestor_filter()`
instead of 20%.
We only need a Page for file:// urls. At some point we probably
needed it for other kinds of requests, but the current functionality
doesn't need to store the Page pointer on the ResourceLoader.
`invalidate_style()` already tries to avoid scheduling invalidation for
`:has()` by checking result of `may_have_has_selectors()`, but it might
still result in unnecessary work because `may_have_has_selectors()`
does not force building of rules cache. This change adds
`have_has_selectors()` that forces building of rules cache and is
invoked in `update_style()` to double-check whether we actually need to
process scheduled `:has()` invalidations.
This allows to skip ~100000 ancestor traversals on this WPT test:
https://wpt.live/html/select/options-length-too-large.html
This is not really a context, but more of a set of parameters for
creating a Parser. So, treat it as such: Rename it to ParsingParams,
and store its values and methods directly in the Parser instead of
keeping the ParsingContext around.
This has a nice side-effect of not including DOM/Document.h everywhere
that needs a Parser.
