Shorthands should be broken up into their longhands, instead of setting
them directly.
There's a catch here with our "positional value list shorthands" like
`margin`: Setting margin to a single value like `CSSUnitValue(10, "px")`
is supposed to fail here, but our type-checking code thinks it's valid
because our JSON for `margin` says it accepts lengths. This is the same
kind of issue that we had for `cursor` discussed in the
"LibWeb/CSS: Support converting CSSUnitValue to a StyleValue" commit.
Will get us a few subtest passes for every shorthand that's tested.
Pending changes to an ancestor document's layout can affect an element's
computed style e.g. an IFrame's width being changed can affect media
query evaluation and the value of the `vw` unit.
StylePropertyMap only ever works with style properties - never
descriptors. Switching `has_property()` and `get_property_style_value()`
to taking PropertyNameAndID skips some duplicate work.
This awkwardly sat as the internal final API for getting a StyleProperty
directly for a given PropertyID, and also the external API for getting
the StyleProperty for a PropertyID. For the latter, it lacked support
for shorthands, and for both it lacked support for custom properties.
This commit:
- Moves the code from get_property() into get_direct_property()
- Makes get_property() call get_property_internal() to support
shorthands
- Adds custom property support for get_direct_property()
This also wins us some WPT points for StylePropertyMap.
We shouldn't include spread distance when serializing `text-shadow` as
it is not supported unlike `box-shadow` - to achieve this we store
whether this is a text or box shadow within the ShadowStyleValue and
serialize appropriately.
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.
