Get rid of the old, roundabout way of invalidating the rule cache by
incrementing the StyleSheetList "generation".
Instead, when something wants to invalidate the rule cache, just have it
directly invalidate the rule cache. This makes it much easier to see
what's happening anyway.
When rules are inserted or removed via the CSSOM API, we now invalidate
document style to ensure that any changes made are reflected.
1% progression on ACID3. :^)
This patch introduces the StyleComputer::RuleCache, which divides all of
our (author) CSS rules into buckets.
Currently, there are two buckets:
- Rules where a specific class must be present.
- All other rules.
This allows us to check a significantly smaller set of rules for each
element, since we can skip over any rule that requires a class attribute
not present on the element.
This takes the typical numer of rules tested per element on Discord from
~16000 to ~550. :^)
We can definitely improve the cache invalidation. It currently happens
too often due to media queries. And we also need to make sure we
invalidate when mutating style through CSSOM APIs.
We now evaluate the conditions of `@media` rules at the same point in
the HTML event loop as evaluation of `MediaQueryList`s. This is not
strictly to spec, but since the spec doesn't actually say when to do
this, it seems to make the most sense. In any case, it works! :^)
We now follow the "update a style block" algorithm from the HTML spec
instead of using the ad-hoc CSSLoader mechanism.
This necessitated improving our StyleSheet and CSSStyleSheet classes as
well, so that's baked into this commit.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
This patch adds bindings for the following objects:
- StyleSheet
- StyleSheetList
- CSSStyleSheet
You can get to a document's style sheets via Document.styleSheets
and iterate through them using StyleSheetList's item() and length().
That's it in terms of functionality at this point, but still neat. :^)
