Some properties like `justify-items`, `grid`, or `display` do affect
layout, but their used values can be obtained without performing a
layout calculation.
This change introduces a new helper,
`property_needs_layout_for_getcomputedstyle()`, specifically for use by
`CSSStyleProperties::property()`. It returns true only for properties
such as `width`, `height`, `margin`, `padding`, `top`, and `left`, where
an up-to-date layout is required to return the correct used value.
This has always been a bit of a hack. Initially it made sense as a lot
of properties that accept a length also accept `auto`, but while
convenient, that leads to problems: It's easy to forget to check if a
length is `auto`, and places that don't accept it end up with an
invalid state lurking in the type system, which makes things unclear.
Not every user of this requires an `auto` state, but most do.
This has quite a big diff but most of that is mechanical:
LengthPercentageOrAuto has `resolved_or_auto()` instead of `resolved()`,
and `to_px_or_zero()` instead of `to_px()`, to make their output
clearer.
Any type of Size which has no LengthPercentage value now uses an empty
optional instead of making an auto Length as before.
We also now serialize a `fit-content` Size as `fit-content` instead of
`fit-content(auto)`, though this doesn't affect test results and I
didn't identify where it's actually used.
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).
This isn't part of the CSSOM API directly, but will be used by
StylePropertyMapReadOnly.has() to avoid doing the work to serialize a
string version of the property's value, just to throw it away again.
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. 😅
...and setter. We had lots of places where we check if pseudo-element
type is specified and then use `pseudo_element_computed_properties()` or
`computed_properties()`. This change moves these checks from caller side
to the getter and setter.
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.
When setting a declaration for a property in a logical property group,
it should appear after all other declarations which belong to the same
property group but have different mapping logic (are/aren't a logical
alias).
Gains us 1 WPT pass.
We should not serialize a group of properties `longhands` as a single
shorthand if there is any property declared between the first and
last property in `longhands` which is not part of `longhands` but
belongs to the same logical property group, and has different mapping
logic to any of property in `longhands`
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.
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.
The spec assumes that we only store values against expanded longhands,
there are however limited circumstances where we store against
shorthands directly in addition to the expanded longhands. For example
if the value of the shorthand is unresolved we store an
UnresolvedStyleValue against the shorthand directly and a
PendingSubstitutionStyleValue against each of the longhands.
This commit updates the logic so that in the case we serialize a
shorthand directly we should also mark it's longhands as serialized to
avoid serializing them separately.
This also avoids the scenario where we tried to create and serialize a
ShorthandStyleValue with PendingSubstitutionStyleValue longhands, so we
can remove the check and related FIXME for that.
Some instances of CSSStyleProperties can lack an owner node, for
instance the return value of a call to `window.getComputedStyle` where
the specified pseudo-element is invalid. In this case we should treat
the computed style as empty, as there is no node to compute the style
for.
The spec requires us to store properties in their shorthand-expanded
form and in the "specified" order, removing duplicates prefering based
on "cascading order". We already enforced this in `set_property` but
not at creation time (e.g. in stylesheets) or in `set_css_text` (e.g.
updating style attribute).
This commit enforces the spec requirements at all the relevant points.
We no longer include logical properties in the return value of
`getComputedStyle` as they are mapped to their physical equivalents in
`StyleComputer::for_each_property_expanding_shorthands`, but resolving
that requires a relatively large rework of how we handle logical
properties, (namely moving when we map them to their physical
equivalents from parse time to style computation time).
This also exposes two false positive tests in
wpt-import/css/cssom/border-shorthand-serialization.html related to us
not yet supporting the border-image css property.
When serializing CSS declarations we now support combining multiple
properties into a single shorthand property in some cases.
This comes with a healthy dose of FIXMEs, including work to be done
around supporting:
- Nested shorthands (e.g. background, border, etc)
- Shorthands which aren't represented by the ShorthandStyleValue type
- Subproperties pending substitution
This gains us a bunch of new test passes, both for WPT and in-tree
This exposed a few bugs which caused the following tests to behave
incorrectly:
- `tab-size-text-wrap.html`: This previously relied on a bug where we
incorrectly treated `white-space: pre` as allowing text wrapping. The
fix here is to implement the text-wrap CSS shorthand property.
- `execCommand-preserveWhitespace.html`: We don't correctly serialize
shorthand properties. This is covered by an existing FIXME in
`CSSStyleProperties::serialized()`
- `white-space-shorthand.html`: The last 5 subtests here fail as we
don't correctly handle shorthand properties in
`CSSStyleProperties::remove_property()`. This is covered by an
existing FIXME in said function.
Which has an optmization if both size of the string being passed
through are FlyStrings, which actually ends up being the case
in some places during selector matching comparing attribute names.
Instead of maintaining more overloads of
Infra::is_ascii_case_insensitive_match, switch
everything over to equals_ignoring_ascii_case instead.
