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.
We were using the font's point size instead of it's pixel size, we were
already computing this information earlier in the function anyway so
let's just use that.
The spec has a general rule for this, which is roughly that "If it's not
a falsey value, it's true". However, a couple of media-features are
always false, apparently breaking this rule. To handle that, we have an
array of false keywords in the JSON, instead of a single keyword. For
those always-false media-features, we can enter all their values into
this array.
Gets us 2 more WPT subtest passes.
Despite what the spec suggests, modern displays are not progressive, and
WPT expects `@media (scan: progressive)` to fail. So, return `none`
here to accurately represent that.
I've left a FIXME in case we can detect the display type from the OS
somehow in the future.
Gets us 4 WPT subtest passes.
Previously, for `foo < 30px` ranges, we'd flip them and store them as
`30px > foo` instead. That worked fine, but means the serialization is
wrong. So instead, keep them in their original form.
I experimented with giving Range two optional sub-structs instead of 4
optional members, thinking it would be smaller - but it's actually
larger, because the two Optional<Comparison>s fit snugly together. So,
the slightly-goofy all-Optionals remains.
This gets us 2 WPT passes that I'm aware of.
Instead of rejecting invalid media-feature values at parse time, we are
expected to parse them, and then treat them as Unknown when evaluating
their media query. To implement this, we first try to parse a valid
value as before. If that fails, or we have any trailing tokens that
could be part of a value, we then scoop up all the possible
ComponentValues and treat that as an "unknown"-type MediaFeatureValue.
This gets us 66 WPT passes.
The current spec defines this simply as `<ident>`, but does apparently
serialize as lowercase.
Because of this change, we no longer need to care about the deprecated
media types, as they all behave the same as unknown ones.
We still keep an enum around for KnownMediaType, to avoid repeated
string comparisons when evaluating it.
Gets us 2 WPT passes.
There's discussion in the linked spec issue, but the short version is,
this algorithm will see "foo,bar," as a list of two groups, with "foo"
in the first group and "bar" in the second. However, users of this want
to get a list of three groups, with the last one being empty. So, do
that!
Some dimensions would always serialize in a canonical unit, others never
did, and others we manually would do so in their StyleValue. This
commit moves all of that into the dimension types, which means for
example that Length can apply its special rounding.
Our local serialization test now produces the same output as other
browsers. :^)
MediaQueryList will now remember if a state change occurred when
evaluating its match state. This memory can then be used by the document
later on when it's updating all queries, to ensure that we don't forget
to fire at least one change event.
This also required plumbing the system visibility state to initial
about:blank documents, since otherwise they would be stuck in "hidden"
state indefinitely and never evaluate their media queries.
