`revert` is supposed to revert to the previous cascade origin, but we
previously had it reverting to the previous layer. To support both,
track them separately during the cascade.
As part of this, we make `set_property_expanding_shorthands()` fall back
to `initial` if it can't find a previous value to revert to. Previously
we would just shrug and do nothing if that happened, which only works
if the value you want to revert to is whatever is currently in `style`.
That's no longer the case, because `revert` should skip over any layer
styles that have been applied since the previous origin.
We now expand shorthands into their respective longhand values when
assigning to a shorthand named property on a CSSStyleDeclaration.
We also make sure that shorthands can be round-tripped by correctly
routing named property access through the getPropertyValue() AO,
and expanding it to handle shorthands as well.
A lot of WPT tests for CSS parsing rely on these mechanisms and should
now start working. :^)
Note that multi-level recursive shorthands like `border` don't work
100% correctly yet. We're going to need a bunch more logic to properly
serialize e.g `border-width` or `border` itself.
Previously, attempting to get the computed value for a
grid-template-rows or grid-template-columns property would cause a crash
if the element had no associated paintable.
Before this change, we were cascading custom properties for each layer,
and then replacing any previously cascaded properties for the element
with only the set from this latest layer.
The patch fixes the issue by making each pass of the custom property
cascade add to the same set, and then finally assigning that set of
properties to the element.
Previously, a crash would occur in the if `CSSPixelFraction` was given a
denominator value less than the resolution of `CSSPixels` (1/64).
We now divide both parts of the ratio by the denominator in this case.
The values of attribute selectors are now compared case insensitively
by default if the attribute's document is not a HTML document, or the
element is not in the HTML namespace.
Right now, we deviate from the CSSOM spec regarding our
CSSStyleDeclaration classes, so this is not as close to the spec as I'd
like. But it works, which means we'll be able to test pseudo-element
styling a lot more easily. :^)
Previously, calling `setProperty` or `removeProperty` from JS on a
CSSStyleDeclaration returned from `getComputedStyle()` would return
null. We now return a NoModificationAllowedError instead, which aligns
our implementation with the specification.
Not every value in a StyleProperties will be non-null by the time we
perform `revert`, so let's make a specialized function for reverting a
property instead of using the path that requires the value to be
non-null.
Pseudo-elements' style is only computed while building the layout tree.
This meant that previously, they would not have their style recomputed
in some cases. (Such as when :hover is applied to an ancestor.)
Now, when recomputing an element's style, we also return a full
invalidation if one or more pseudo-elements would exist either before or
after style recomputation.
This heuristic produces some false positives, but no false negatives.
Because pseudo-elements' style is computed during layout building, any
computation done here is then thrown away. So this approach minimises
the amount of wasted style computation. Plus it's simple, until we have
data on what approach would be faster.
This fixes the Acid2 nose becoming blue when the .nose div is hovered.
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.
Previously, we always cast to a HTMLInputElement when getting the value
of an auto directionality form associated element. This caused
undefined behavior when determining the directionality of an element
that wasn't a HTMLInputElement.
The if statement in the dispatch implies we are in the idle state, so of
course the active time will always be undefined. If this was cancelled
via a call to cancel(), we can save the time at that point. Otherwise,
just send 0.
Previously, we would apply any adopted style sheet to the document if
its alternate flag was not set. This meant that all adopted style
sheets would be applied, since constructed style sheets never have this
flag set.
We have to unregister link element stylesheets from the old document's
StyleSheetList when moving them into a new document.
This makes it possible to load GitHub contributor graphs. :^)
There were two things going wrong here:
- Transformed text (via CSS text-transform) was not invalidated after a
`@media` rule changed state.
- Removing the `style` attribute from an element didn't trigger a style
update.
This fixes the regression in subtest 46 of Acid3.
Fixes#21777
Previously @media rule conditions could be updated by assigning to
`conditionText`. This change aligns our implementation with the CSSOM
specification, which says `CSSConditionRule.conditionText` should be
read-only.
This method asynchronously replaces the content of the given stylesheet
with the content passed to it.
An exception is thrown if this method is used by a stylesheet not
created with the `CSSStyleSheet()` constructor.
When the caller of NumericCalculationNode::resolve() does not provide
a percentage_basis, it expects the method to return a raw percentage
value.
Fixes crashing on https://discord.com/login
