If a rule gets its caches cleared because it's moved in the OM, then its
child rules' caches are likely invalid and need clearing too.
Assuming that caches only point "upwards", this will correctly clear
them all. For the time being that will be true.
All its overrides return constants, and without virtual dispatch the
`qualified_layer_name` and `absolutized_selectors` functions can benefit
from slightly better optimizations.
`CSSRule`s aren't allocated that often, so the memory impact is minimal.
I didn't want to add another set of boilerplatey tree-walking methods,
so here's a general-purpose one. :^)
`for_each_effective_rule()` walks the tree of effective style rules, and
runs the callback on each one, in either pre- or postorder. The
previous `for_each_effective_style/keyframes_rule()` methods of
`CSSStyleSheet` are then reimplemented in terms of
`for_each_effective_rule()`, and we can get rid of their equivalents
elsewhere.
This partially implements CSS-Animations-1 (though there are references
to CSS-Animations-2).
Current limitations:
- Multi-selector keyframes are not supported.
- Most animation properties are ignored.
- Timing functions are not applied.
- Non-absolute values are not interpolated unless the target is also of
the same non-absolute type (e.g. 10% -> 25%, but not 10% -> 20px).
- The JavaScript interface is left as an exercise for the next poor soul
looking at this code.
With those said, this commit implements:
- Interpolation for most common types
- Proper keyframe resolution (including the synthetic from-keyframe
containing the initial state)
- Properly driven animations, and proper style invalidation
Co-Authored-By: Andreas Kling <kling@serenityos.org>
Note that as of this commit, there aren't any such throwers, and the
call site in Heap::allocate will drop exceptions on the floor. This
commit only serves to change the declaration of the overrides, make sure
they return an empty value, and to propagate OOM errors frm their base
initialize invocations.
This needs to happen before prototype/constructor intitialization can be
made lazy. Otherwise, GC could run during the C++ constructor and try to
collect the object currently being created.
This is a monster patch that turns all EventTargets into GC-allocated
PlatformObjects. Their C++ wrapper classes are removed, and the LibJS
garbage collector is now responsible for their lifetimes.
There's a fair amount of hacks and band-aids in this patch, and we'll
have a lot of cleanup to do after this.
Both of these are supposed to be set when the CSSRule is created. The
spec is silent on setting it when a CSSRule is added to a parent. So,
this is a bit ad-hoc.
The parent rule gets set whenever a rule is added to a new parent. The
parent stylesheet gets set whenever the rule or one of its ancestors is
added to a different stylesheet. There may be some nuance there that
I'm missing, but I'm sure we'll find out quickly once we have WPT
running!
The `CSSMediaRule::serialized()` code is to spec. The
`CSSSupportsRule::serialized()` code has no spec right now, but I'm
fairly confident it will be almost identical to media's, so I copied
that for now.
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! :^)
The logic is handled by `CSSGroupingRule` and `CSSConditionRule`, so
`CSSMediaRule` only has to report if its condition matches.
Right now, that condition is always false because we do not evaluate the
media query.
There are a handful of FIXME's here, but this seems generally good.
Note that CSS *values* don't get serialized in a spec-compliant way
since we currently rely on StyleValue::to_string() which is ad-hoc.
This patch makes both of these classes inherit from RefCounted and
Bindings::Wrappable, plus some minimal rejigging to allow us to keep
using them internally while also exposing them to web content.
