e.g., `@container (width >= 300px) {}` and similar.
During style computation, flag any elements whose style depends on a
size container. Then re-evaluate their style after the initial layout
has been computed and size containers have a size. This may take
multiple passes, as these may have further descendants that depend on
their size, etc. We limit this to 8 passes currently.
SizeFeature itself is very similar to MediaFeature, but queries the
container element instead. There are only 6 size features specified, so
they're hard-coded instead of generated from JSON.
Also add a counter test for the narrower restyle path.
Replace `ContainerQueryFeatureRequirements::requires_size_container`
with separate width and height flags. Depending on the writing mode, a
request for the width or height of a container might need it to be a
size container, or only an inline-size container. Anything that needs
both sizes (such as the aspect ratio) can simply flag both as required.
A given element may be a container in different ways, depending on its
`container-type` property. For a container query to match an element,
that element must have the required container type for each feature
that the query checks. This commit implement a step to collect those
required types, so that we can quickly eliminate potential container
elements that lack a required containment type.
Different users of BooleanExpression have different requirements for
evaluation:
- `@media` needs a Document
- `@supports` doesn't need anything
- `@container` needs a container Element
To support these without expanding the API, replace the Document*
parameter with a BooleanExpressionEvaluationContext type which contains
these different values.
No behaviour changes.
Previously we would always use the window's viewport which was incorrect
if we were within an iframe.
This is likely applicable to all uses of
`Length::ResolutionContext::for_window`.
Functionally this is the same before, as result is always True or False
before this point, and `True && Foo` evaluates to `Foo`. But this is
more clearly correct, instead of correct by coincidence.
CSS Values 5 now defines a `<boolean-expr[]>` type that is used in place
of the bespoke grammar that previously existed for `@media` and
`@supports` queries. This commit implements some BooleanExpression
types to represent the nodes in a `<boolean-expr[]>`, and reimplements
`@media` and `@supports` queries using this.
The one part of this implementation I'm not convinced on is that the
`evaluate()` methods take a `HTML::Window*`. This is a compromise
because `@media` requires a Window, and `@supports` does not require
anything at all. As more users of `<boolean-expr[]>` get implemented in
the future, it will become clear if this is sufficient, or if we need
to do something smarter.
As a bonus, this actually improves our serialization of media queries!
