Previously we only supported a subset of the predefined counter styles,
we now respect counter styles defined by `@counter-style` rules when
resolving the value of `counter()` and `counters()` functions
There are some predefined counter styles (such as the longhand east
asian ones) which are too complex to be defined here and will need to be
implemented ad-hoc, this remains as a FIXME for now.
The tricky bit of this is resolving cycles in extending rules and
ensuring that counter styles are registered in the required order for
extension (i.e. for any pair of extended/extending rules the extended
one should be registered first).
Each NodeWithStyle is assigned a sequential layout index during the
pre-layout tree traversal. LayoutState stores UsedValues in a
PagedStore — a two-level page table indexed by layout_index that
gives O(1) lookup via two array accesses, with pages allocated
lazily on first write. UsedValues are stored directly in pages
(Optional<T>) rather than behind heap pointers, eliminating
per-entry malloc/free calls and improving cache locality.
This cuts ensure_used_values_for() from ~14% to ~7% in profiles
on https://www.nyan.cat/.
The cursor blink timer fires every 500ms and only needs to toggle
the blink state and mark the paintable as needing display. If the
paintable doesn't exist yet, we can simply skip the blink -- the
cursor will appear after the next natural rendering update.
This avoids a potentially expensive synchronous layout every 500ms
for what is a purely cosmetic operation.
These properties only return the computed border width, which is a
style-level value that doesn't depend on layout geometry. Replace
the full update_layout() call with update_style_if_needed_for_element()
and resolve border widths directly from computed properties.
This avoids potentially expensive synchronous layout when only
CSS computed values are needed.
Very profitable on https://x.com/ where we avoid lots of layout work.
Setting the filter property on a CanvasRenderingContext2D would crash
with a null pointer dereference if the canvas element had no layout
node (e.g. a detached canvas not in the document).
Instead of forcing a full layout update and requiring a layout node,
we now only update style if needed and resolve lengths via the
element's computed properties when available, falling back to
document-level defaults otherwise. This matches the pattern used by
CanvasTextDrawingStyles.
This is a targeted version of update_style() that only performs a
style update if the given element (or its ancestors) actually have
dirty style. Useful when we only need up-to-date computed properties
for a specific element.
Eliminate O(n) tree-order sorted insert on every add() by simply
appending elements and deferring order resolution to lookup time. Cache
the first-in-tree-order element in get() so repeated getElementById()
calls avoid repeated subtree traversal.
Improves performance on YouTube where add() was hot in profiles while
scrolling through comments.
Since we now maintain cached state (m_in_editable_subtree) in the base
Node::moved_from(), subclasses must always call up to ensure the flag
is recomputed. Mark it MUST_UPCALL like inserted() and removed_from().
Add a cached m_in_editable_subtree flag to Node, updated on tree
mutations and contenteditable/designMode changes.
This replaces the recursive parent walk in is_editable() and
is_editing_host() with an O(1) flag check. The flag is recomputed
in inserted(), moved_from(), and cleared in removed_from(). Subtree
walks recompute the flag when contenteditable attributes change or
design mode is toggled.
This was 4% of CPU time while playing a YouTube video.
Absolutely positioned elements inside SVG foreignObject were being
positioned relative to an ancestor containing block outside the SVG,
instead of relative to the foreignObject itself. Per a W3C resolution
and the behavior of other browsers, foreignObject should establish a
containing block for absolutely and fixed positioned elements.
With this fix, the `has_abspos_with_external_containing_block` check
in `set_needs_layout_update()` and the abspos preservation loop in
`relayout_svg_root()` become dead code — remove both and simplify the
ancestor loops. Rename related tests to reflect the new behavior.
Fixes https://github.com/LadybirdBrowser/ladybird/issues/3241
We were mimicking Firefox' behavior that whenever a programmatic change
to an <input>'s or <textarea>'s selection happened, the new selection
focus is brought into view by scrolling. Currently we run a layout
update synchronously for that to make sure we have the fragment's
correct dimensions, which caused a significant performance regression in
Speedometer.
Since this is non-standard behavior, let's mimic Chromium instead which
does not scroll at all - only for direct user initiated input such as
typing.
Relevant issues:
* https://github.com/whatwg/html/issues/6217
* https://bugzilla.mozilla.org/show_bug.cgi?id=232405
* https://issues.chromium.org/issues/41081857
Elements in internal shadow trees that represent CSS pseudo-elements
(e.g. the DetailsContent slot in <details>) store their cascaded
properties on the host element's pseudo-element data, not on the
element itself. This meant that when slotted elements walked the
inheritance chain and encountered such a slot, they would dereference
null cascaded properties and crash.
Fix this by copying the cascaded properties onto the slot element
itself after computing its style, keeping both cascaded and computed
properties accessible in the same place.
By making use of the WEB_PLATFORM_OBJECT macro we can remove
the boilerplate of needing to add this override for every
serializable platform object so that we can check whether they
are exposed or not.
Move the dispatch_events_for_animation_if_necessary() calls into step 1
of update_animations_and_send_events(), where the spec note says
updating timelines involves "Queueing animation events for any such
animations." Previously, these calls ran after step 7 (event dispatch),
causing newly queued events to be deferred by an extra rendering update.
This meant that e.g. a CSS transition triggered during an earlier
rendering step would not have its transitionrun event fired until the
next frame, instead of the current one.
Dispatching scroll events could cause new scroll events to get lined up
and added to `m_pending_scroll_events`. The spec then asks us to empty
out that list, removing those newly added events.
Prevent doing that by emptying out the list before iterating over the
events. Fixes part of the WPT test `html/webappapis/scripting/event-
loops/new-scroll-event-dispatched-at-next-updating-rendering-time.html`.
We were using a separately fired timer for auto scrolling ticks, but it
makes more sense to tie this into the rendering steps of which
`::run_the_scroll_steps()` is a part. Should fix the flaky
`Text/input/viewport-auto-scroll.html` test.
Fixes#7939.
Previously we computed font properties separately from other properties
for two reasons:
1) These font properties were computed using a different length
resolution context than the rest of the properties.
2) These properties were required to be computed before creating the
length resolution context for the rest of the properties.
The first issue was solved in the previous commit by introducing a
generic method to get the computation context for a property, and
the second is solved in this commit by computing properties in the
required order.
This simplifies the code a bit and opens up some opportunities for
optimization.
Change the parameters types of the functions `coarsen_time` and
`coarsened_shared_current_time` from `bool` to
`CanUseCrossOriginIsolatedAPIs` for more coherence with the surrounding
code.
Replace per-element OrderedHashMap storage for custom properties with
a RefCounted chain (CustomPropertyData) that enables structural
sharing. Each chain node stores only the properties declared directly
on its element, with a parent pointer to the inherited chain.
Elements that don't override any custom properties share the parent's
data directly (just a RefPtr copy). During cascade, only entries that
actually differ from the parent are stored in own_values - the rest
are inherited through the chain. During var() resolution, resolved
values are compared against the parent's and matching entries are
dropped, enabling further sharing.
The chain uses a depth limit (max 32) with flattening, plus
absorption of small parent nodes (threshold 8) to keep lookups fast.
This reduces custom property memory from ~79 MB to ~5.7 MB on
cloudflare.com.
Two issues prevented slotted elements from correctly inheriting
styles from their assigned slot:
1. Element::element_to_inherit_style_from() was skipping the slot
element and returning the shadow host instead. This meant slotted
elements inherited from the host, completely ignoring any styles
on the slot itself.
2. When a slot element's style changed during the style tree walk,
its assigned (slotted) nodes were never marked for recomputation.
The tree walk follows the DOM tree, but slotted elements are DOM
children of the shadow host, not the slot, so they were missed.
Fix (1) by returning the slot directly as the inheritance parent.
Fix (2) by marking assigned nodes dirty in update_style_recursively
when a slot's style changes.
Before calling update_style() for a getComputedStyle property access,
we now check whether the target element actually needs a style update
by walking the flat tree ancestor chain. If neither the element nor any
of its ancestors have dirty style bits, and there are no document-level
reasons to recalculate style, we skip the update_style() call entirely.
We walk the flat tree (not the DOM tree) because style inheritance
follows slot assignment -- slotted elements inherit from their assigned
slot, not their DOM parent.
This avoids unnecessary work when scripts access computed style
properties on elements whose styles are already up-to-date, which is a
common pattern on the web.
Previously, `<link rel=stylesheet>` would delay the load event until its
style sheet loaded, but not care about its subresources. `<style>`
would not delay the load event at all. Instead, each `@import` would
delay the load event.
Now, both `<style>` and `<link>` delay the load event until their style
sheet and its critical subresources have loaded or failed. This means
that CSSImportRules no longer need to delay the load event themselves,
because they do so implicitly as a critical subresource of their parent
style sheet.
This doesn't directly affect behavior, but means that any other critical
style resources we add will automatically delay the load event.
One wrinkle here is that the spec for the `<link>` element requires that
we wait for the style sheet's critical subresources *before* we create
a CSSStyleSheet, which means we don't yet know what those are.
https://html.spec.whatwg.org/multipage/semantics.html#fetching-and-processing-a-resource-from-a-link-element:critical-subresources
For now we simply ignore this, as we did before. That means we continue
to not delay the `<link>`'s load event.
Previously, we fired the load event immediately, without waiting for
anything. This was good for not timing out, but bad for anything that
wanted to wait for the load to complete.
CSSStyleSheet now maintains a list of critical subresources, and waits
for all of them to complete before it then tells its owner that it is
ready. "Complete" here means the network request completed with or
without an error. This is done by having those subresources (just
`@import` for now) notify their style sheet when they complete. This
then propagates up as an `@import` tells its style sheet, which then
would tell its parent `@import` if it had one.
There are other subresources we should wait for (specifically fonts and
background images) but this commit just adds `@import` as a first step.
Remove unused/redundant includes from Element.h:
- AK/IterationDecision.h (redundant)
- ARIA/AttributeNames.h (redundant via ARIAMixin.h)
- CSS/CascadedProperties.h (redundant via PseudoElement.h)
- CSS/StylePropertyMapReadOnly.h (pointer types only)
- HTML/LazyLoadingElement.h (unused in header)
Extract IntersectionObserverRegistration struct from
IntersectionObserver.h into its own lightweight header.
This breaks the heavy transitive include chain through
IntersectionObserverEntry.h and Geometry/DOMRect.h that
was pulled into every file including Element.h.
Indirect recompilation impact reductions:
- IntersectionObserver.h: ~1387 -> ~27 files
- LazyLoadingElement.h: ~1387 -> ~1002 files
Remove includes from Node.h that are only needed for forward
declarations (AccessibilityTreeNode.h, XMLSerializer.h,
JsonObjectSerializer.h). Extract StyleInvalidationReason and
FragmentSerializationMode enums into standalone lightweight
headers so downstream headers (CSSStyleSheet.h, CSSStyleProperties.h,
HTMLParser.h) can include just the enum they need instead of all of
Node.h. Replace Node.h with forward declarations in headers that only
use Node by pointer/reference.
This breaks the circular dependency between Node.h and
AccessibilityTreeNode.h, reducing AccessibilityTreeNode.h's
recompilation footprint from ~1399 to ~25 files.
Remove 11 heavy includes from Document.h that were only needed for
pointer/reference types (already forward-declared in Forward.h), and
extract the nested ViewportClient interface to a standalone header.
This reduces Document.h's recompilation cascade from ~1228 files to
~717 files (42% reduction). Headers like BrowsingContext.h that were
previously transitively included see even larger improvements (from
~1228 down to ~73 dependents).
Previously only input elements were matched. Add placeholder_value()
to HTMLTextAreaElement mirroring the HTMLInputElement API and update
both selector matching code paths to handle textarea.
If we want to test whether or not we're drawing the caret, we need to
prevent it from blinking or otherwise all tests we're going to write
that look at the display list will turn out to be flaky.
When the mouse is dragged from inside a scrollable container to outside
of it, we now automatically scroll the container so the selection can be
extended. Scroll speed scales with the distance past the scrollport
edge, capped at a maximum. Edges close to the viewport boundary get a
wider activation zone so the speed ramp works predictably even when the
mouse has limited room to move.
The logic is encapsulated in AutoScrollHandler, which EventHandler
creates lazily on mouse selection start.
When editing or changing the selection inside an <input> or <textarea>,
we should scroll the container so the cursor is always visible. Note
that currently the cursor might still become invisible at the end of the
container since we do not reserve enough space for it to be made
visible.
