Parsing a `Gfx::Color` no longer makes sense, as CSS has many ways of
defining a color, often in a dynamic way where the color value isn't
known until later. This is a small preparatory change before a much
larger color rewrite.
Soon, CSSColorValue will be an abstract class, and we'll instead create
a CSSRGB, CSSHSL, or other specific color type from the Typed-OM spec.
However, it's still useful to have an easy "just give me a style value
for this color" method. So change the name to distinguish this from the
usual StyleValue::create() methods.
We previously had 4 single-instance StyleValues for these keywords.
CSS-Typed-OM expects them keywords to be exposed as CSSKeywordValue, so
it's simpler to treat them the same. The single-instance behaviour is
kept by having StyleValue::create() use a cached instance for each of
these.
For a long time, we've used two terms, inconsistently:
- "Identifier" is a spec term, but refers to a sequence of alphanumeric
characters, which may or may not be a keyword. (Keywords are a
subset of all identifiers.)
- "ValueID" is entirely non-spec, and is directly called a "keyword" in
the CSS specs.
So to avoid confusion as much as possible, let's align with the spec
terminology. I've attempted to change variable names as well, but
obviously we use Keywords in a lot of places in LibWeb and so I may
have missed some.
One exception is that I've not renamed "valid-identifiers" in
Properties.json... I'd like to combine that and the "valid-types" array
together eventually, so there's no benefit to doing an extra rename
now.
These have a few rules that we didn't follow in most cases:
- CSS-wide keywords are not allowed. (inherit, initial, etc)
- `default` is not allowed.
- The above and any other disallowed identifiers must be tested
case-insensitively.
This introduces a `parse_custom_ident_value()` method, which takes a
list of disallowed identifier names, and handles the above rules.
This is `counter(name, style?)` or `counters(name, link, style?)`. The
difference being, `counter()` matches only the nearest level (eg, "1"),
and `counters()` combines all the levels in the tree (eg, "3.4.1").
These control the state of CSS counters.
Parsing code for `reversed(counter-name)` is implemented, but disabled
for now until we are able to resolve values for those.
The new method is Parser::parse_all_as_single_none_value(), which has a
few advantages:
1. There's no need for user code to manually create a StyleValue.
2. It consumes tokens so that doesn't have to be done manually.
3. Whitespace before or after the `none` is consumed correctly.
It does mean we create and then discard a `none` StyleValue in a couple
of places, namely parsing for `grid-*` properties. We may or may not
want to migrate those to returning the IdentifierStyleValue instead.
We already have a FlyString of its value from parsing, and most users
also want a FlyString from it, so let's use that instead of converting
backwards and forwards.
The two users that did want a String are:
- Quotes, which make sense as FlyString instead, so I've converted that.
- Animation names, which should probably be FlyString too, but the code
currently also allows for other kinds of StyleValue, and I don't want
to dive into this right now to figure out if that's needed or not.
The values aren't that complex, so it doesn't make much sense to have a
dedicated generator for them. Parsing them manually also allows us to
have much more control over the produced values, so as a result of this
change, EasingStyleValue becomes much more ergonomic.
As the parser was trying to directly unwrap an unresolved duration.
Currently we are outputting the wrong results for the serialized
duration, but this is still a step forwards.
Fixes a crash seen on: https://evaparish.com/blog/how-i-edit
Before this change, every CSS @supports rule would keep the containing
JS realm alive via a JS::Handle. This led to a GC reference cycle and
the whole realm leaked.
Since we only need the realm at construction time, we can take it as a
parameter instead, and stop storing it.
