Previously, we fired the load event immediately, without waiting for
anything. This was good for not timing out, but bad for anything that
wanted to wait for the load to complete.
CSSStyleSheet now maintains a list of critical subresources, and waits
for all of them to complete before it then tells its owner that it is
ready. "Complete" here means the network request completed with or
without an error. This is done by having those subresources (just
`@import` for now) notify their style sheet when they complete. This
then propagates up as an `@import` tells its style sheet, which then
would tell its parent `@import` if it had one.
There are other subresources we should wait for (specifically fonts and
background images) but this commit just adds `@import` as a first step.
Previously, getComputedStyle() would always call update_layout() for
most properties. This was expensive since layout involves a full tree
traversal even when only style information is needed.
This change introduces a more granular approach:
- Properties needing layout computation (used values like width/height)
still call update_layout()
- Properties needing a layout node for resolved value computation
(colors, border widths, etc.) also call update_layout()
- All other properties now only call update_style()
The set of properties needing layout node for resolution is now defined
in Properties.json via the "needs-layout-node-for-resolved-value" flag,
rather than being hardcoded. This is generated into a new function
property_needs_layout_node_for_resolved_value().
Specifically, we create and assign a layer if its import conditions
currently apply.
With this change, every case in the `layer-import.html` test actually
functions correctly, apart from our lack of proper `load` event
support. (Tested by hacking in a 100ms wait after the `await Promise()`
statement.)
...instead of returning the one from its associated style sheet.
This reverts 848a250b29 where I made
`CSSImportRule.media` nullable.
CSSImportRule may not have an associated style sheet, because of not
matching a supports condition, or just failing to load the URL.
Regardless of whether we do or not, the expected (non-spec) behaviour
is that we should return a MediaList always, which matches the media
queries specified on the `@import` rule.
Fixes some WPT tests that expected `supports(foo:bar)` to serialize as
`supports(foo:bar)`, instead of `supports(foo: bar)` with a space
between.
Reading the original_full_text directly also lets us delete
Declaration::to_string(), which was only used here.
The previous implementation assumed that the contents of `supports()`
was either a raw declaration, or a block containing some number of them.
This meant we wouldn't parse things like `supports(not (a:b))` or
`supports(selector(*))`.
`parse_a_supports()` actually does what we want in every case except for
raw declarations (`supports(a: b)`), so let's always call it first, and
then fall back to parsing a single declaration.
The remaining failing tests in view-timeline-shorthand.html are due to
either:
a) incorrect tests, see web-platform-tests/wpt#56181 or;
b) a wider issue where we collapse coordinating value list longhand
properties to a single value when we shouldn't.
The remaining failing tests in scroll-timeline-shorthand.html are due to
either:
a) incorrect tests, see web-platform-tests/wpt#56181 or;
b) a wider issue where we collapse coordinating value list longhand
properties to a single value when we shouldn't.
This applies size, inline-size, and style containment in some cases.
There are other WPT tests for that, but we seem to not implement enough
of containment for this to have an effect so I've not imported those.
Gets us 35 WPT subtests.
This introduces the `TextUnderlinePositionStyleValue` class, it is
possible to represent `text-underline-position` as a `StyleValueList`
but would have required ugly workarounds for either serialization or in
`ComputedProperties::text_underline_position`
This property provides a hint to the rendering engine about properties
that are likely to change in the near future, allowing for early
optimizations to be applied.
