Move the layout tree from GC allocation to refcounted ownership so
removed layout and paint subtrees are destroyed synchronously instead
of waiting for the next GC sweep. This dramatically reduces GC memory
usage peaks after layout tree churn and makes it easier for memory use
to fall back after large document updates.
Update layout factories, tree traversal, SVG layout node creation,
paintable back-pointers, and pseudo-element layout links to use RefPtr
ownership.
Make display: contents follow the same shape as Blink and WebKit: the
element itself does not create a layout node, and its children are
flattened into the nearest layout parent. Wrap direct non-whitespace
text in an anonymous inline node when the boxless element contributes
inherited style to that text.
Use an internal inline wrapper for display: contents pseudo-elements
so generated content can still participate in layout, painting, hit
testing, and pseudo-element queries. Keep CSSOM reporting the computed
display value from the pseudo style, not the internal wrapper.
Remove the retained out-of-tree layout node list and its testing hook,
since the flattened model does not need a side owner for boxless
elements. Add coverage for inherited text style, dynamic insertion
order, pseudo-element hit testing, and computed style queries.
Enable -Wexit-time-destructors for all in-tree library targets and
update process-lifetime library statics so they no longer register
exit-time destructors. Long-lived caches, lookup tables, singleton
registries, and generated constants now use NeverDestroyed or leaked
references where the data is intended to live until process exit.
Update LibWeb, LibLine, and the binding generators so regenerated
sources follow the same rule instead of reintroducing destructed
statics.
Parse subgrid track listings for grid-template rows and columns,
including fixed and auto-fill name-repeat line-name lists. Preserve
the subgrid keyword through computed values and shorthand serialization,
and make interpolation discrete instead of routing subgrid lists through
the explicit track interpolation path.
Import WPT coverage for subgrid grid-template parsing and computed
values, and add text coverage for discrete subgrid track-list animation.
Fall back to discrete transform interpolation when a remaining
transform list needs a reference box to become a matrix and none is
available. Percentage translate values otherwise reached
Length::from_style_value() without a percentage basis.
Add a crash test covering computed Typed OM access to an interpolated
transform that mixes percentage translation with rotation.
Parameter values are absolutized at style computation time (or are
confirmed to be resolvable in the case of reification or DOMMatrix) so
there is no reason this function should fail.
The Paintable tree and its supplemental painting data structures were
GC allocated because that was the easiest way to manage it and avoid
leaks introduced by ref cycles. This included the Paintable subclasses
themselves plus StackingContext, ChromeWidget, Scrollbar, ResizeHandle,
and scroll-frame state.
We are now trying to reduce GC allocation churn on layout and painting
updates, so keeping this short-lived rendering tree outside the JS heap
is a better fit. Move Paintable to RefCountedTreeNode, make painting
helpers ref-counted or weakly reference Paintables, and update the
layout and event-handler call sites to use RefPtr/WeakPtr ownership.
The newly failing tests in
`css-display/animations/display-interpolation.html` are due to the test
not having been updated for the new spec level and is in line with other
browsers.
Currently there are multiple style values which are essentially the same
thing, a function holding a value, just with different names. This
commit adds a generic style value to replace them with and the following
commits will do so.
This allows us to avoid the ugly hack in
`property_accepted_type_ranges()`.
This also updates the `ValueType` to be `opacity-value` rather than
`opacity` to match the spec.
This simplifies handling (particularly around absolutization and
interpolation) and allows us to support calculated flex values (which
will come in a later commit).
Per the CSS Transforms spec, when interpolating rotate3d() functions
with equal normalized direction vectors (or when one angle is zero),
the rotation angle should be interpolated numerically rather than
using quaternion slerp.
Previously we always used quaternion slerp, which cannot represent
rotations beyond 360 degrees. This meant that animating from
rotateY(0deg) to rotateY(3600deg) produced no visual animation, since
both quaternions are identical (3600 mod 360 = 0).
Now we detect when axes match and interpolate the angle directly,
correctly preserving multi-turn rotations. This fixes 168 WPT tests.
Per the CSS Transforms spec, when one of the matrices for interpolation
is non-invertible (i.e. cannot be decomposed), the animation must fall
back to discrete interpolation.
Previously we would silently drop the transform, producing "none". Now
we correctly snap between the from/to values at the 50% progress mark,
matching the behavior required by the spec and other browsers.
Also propagate to_matrix() errors instead of silently using a partial
result, and use the previously-unused AllowDiscrete parameter.
Add unsafe_layout_node(), unsafe_paintable(), and unsafe_paintable_box()
accessors that skip layout-staleness verification. These are for use in
contexts where accessing layout/paintable data is legitimate despite
layout not being up to date: tree construction, style recalculation,
painting, animation interpolation, DOM mutation, and invalidation
propagation.
Also add wrapper APIs on Node to centralize common patterns:
- set_needs_display() wraps if (unsafe_paintable()) ...set_needs_display
- set_needs_paint_only_properties_update() wraps similar
- set_needs_layout_update() wraps if (unsafe_layout_node()) ...
And add Document::layout_is_up_to_date() which checks whether layout
tree update flags are all clear.
This exposes an existing issue with interpolation where it is not clear
in what situations zero-valued dimensions should be excluded from the
interpolated value of a dimension-percentage mix (e.g. `calc(50% + 0px)`
vs `50%`) - but this is just a serialization issue as both
representations are resolved to the same used value
This means we don't need to include `FilterValueListStyleValue.h` in as
many places - reducing the rebuild from editing that file from 717 files
to 19.
This also required supporting composition for it's constituent types
(`RadialSizeStyleValue` and `BorderRadiusRect`).
The remaining failing subtests in the two affected tests are because we
dont yet support compositing of mixed values
This means we now allow oblique angles when parsing the `font`
shorthand.
This also required us to rename the existing `FontStyle` enum to
`FontStyleKeyword`
As well as being required to implement absolutization this also means we
now bypass a limitation with `LengthPercentage` where we would always
use `SerializationMode::Normal` for the constituent lengths which gains
us some WPT passes
The Transformation class wasn't really accomplishing anything. It still
had to store StyleValues, so it was basically the same as
TransformationStyleValue, with extra steps to convert from one to the
other. So... let's just use TransformationStyleValue instead!
Apart from moving code around, the behavior has changed a bit. We now
actually acknowledge unresolvable parameters and return an error when
we try to produce a matrix from them. Previously we just skipped over
them, which was pretty wrong. This gets us an extra pass in the
typed-om test.
We also get some slightly different results with our transform
serialization, because we're not converting to CSSPixels and back.
