Otherwise removal of stylesheets may get out of sync with other DOM changes, and
we may fail to invalidate the style of the affected elements.
Bug: 1432850
Reviewed-by: bz
MozReview-Commit-ID: DrMTgLzQcnk
Now that we have an Element around on cascade, we can stop using the cascade
flags mechanism to pass various element-related state, like "is this element the
root", or "should it use the item-based display fixup".
That fixes handwaviness in the handling of those flags from style reparenting,
and code duplication to handle tricky stuff like :visited.
There are a number of other changes that are worth noticing:
* skip_root_and_item_based_display_fixup is renamed to skip_item_display_fixup:
TElement::is_root() already implies being the document element, which by
definition is not native anonymous and not a pseudo-element.
Thus, you never get fixed-up if your NAC or a pseudo, which is what the code
tried to avoid, so the only fixup with a point is the item one, which is
necessary.
* The pseudo-element probing code was refactored to return early a
Option::<CascadeInputs>::None, which is nicer than what it was doing.
* The visited_links_enabled check has moved to selector-matching time. The rest
of the checks aren't based on whether the element is a link, or are properly
guarded by parent_style.visited_style().is_some() or visited_rules.is_some().
Thus you can transitively infer that no element will end up with a :visited
style, not even from style reparenting.
Anyway, the underlying reason why I want the element in StyleAdjuster is because
we're going to implement an adjustment in there depending on the tag of the
element (converting display: contents to display: none depending on the tag), so
computing that information eagerly, including a hash lookup, wouldn't be nice.
This more concrete wrapper type can write a prefix the very first time something
is written to it. This allows removing plenty of useless monomorphisations caused
by the former W/SequenceWriter<W> pair of types.
Returning a zero-sized viewport in the case there's no shell / pres context.
For now, no other change yet. After this we can start tweaking the ShadowRoot
Stylist setup, and even try to return computed styles without a document \o/.
Bug: 1430608
MozReview-Commit-ID: 3cT2PKQISri
style: Add a document state invalidator.
Don't use it yet (since I was working from a Servo tree). Will hook it up and improve in the Gecko bug.
Right now it takes a `StyleRuleCascadeData`, which means that if all the origins in the document have state selectors we could do just one walk over the tree and not multiple, that will be improved.
Other than that, this is completely untested of course, but I prefer to land it, given I don't think it's complex, and work on the Gecko integration separately. The reason for this is that I also plan to fix the `<slot>` bugs, which will change `StyleRuleCascadeData` and such, and I want the two bugs to conflict as little as possible.
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Now that accessing nsIContent slots is not a blob of virtual function calls, we
should be able to unify logic here, and speed up the not-so-rare case for
chrome, while keeping the usual case fast.
Bug: 1427511
Reviewed-by: smaug
MozReview-Commit-ID: 87iY5Cbhx4T
