We maintain a registry of elements with an anchor-name so once they are
referenced for anchor positioning, we can find them with an O(1) lookup
instead of traversing the entire DOM tree.
This cannot happen inside the Make Active algorithm, since that gets
called during document creation, which commonly happens before the
document's navigable is created.
Aligns us with a recent spec change and rids us of some AD_HOC
behavior.
Now that Navigable directly owns its active document (m_active_document)
we can have Navigable maintain a back-pointer on Document instead of
using the old cache-with-validation pattern that fell back to a linear
scan of all navigables via navigable_with_active_document().
Previously, the active document's lifecycle was bound to
SessionHistoryEntry via DocumentState. The ownership chain was:
Navigable → SessionHistoryEntry → DocumentState → Document
This made it impossible to move SessionHistoryEntry to the UI process
(which cannot own DOM::Document). This commit decouples the two by
giving Navigable a direct m_active_document field that serves as the
authoritative source for active_document().
- Navigable owns m_active_document directly; active_document() reads
from it instead of going through the active session history entry.
- DocumentState no longer holds a Document pointer. Instead, it stores
a document_id for "same document?" checks. Same-document navigations
share a DocumentState and thus the same document_id, while
cross-document navigations create a new DocumentState with a new ID.
- A pending_document parameter is threaded through
finalize_a_cross_document_navigation → apply_the_push_or_replace →
apply_the_history_step so the newly created document reaches
activation without being stored on DocumentState.
- For traversal, the population output delivers the document.
A resolved_document is computed per continuation from either the
pending document, the population output, or the current active
document (for same-document traversals).
Replace the blocking spin_processing_tasks_with_source_until calls
in apply_the_history_step_after_unload_check() with an event-driven
ApplyHistoryStepState GC cell that tracks 5 phases, following the
same pattern used by CheckUnloadingCanceledState.
Key changes:
- Introduce ApplyHistoryStepState with phases:
WaitingForDocumentPopulation, ProcessingContinuations,
WaitingForChangeJobCompletion, WaitingForNonChangingJobs and Completed
- Add on_complete callbacks to apply_the_push_or_replace_history_step,
finalize_a_same_document_navigation,
finalize_a_cross_document_navigation, and
update_for_navigable_creation_or_destruction
- Remove spin_until from Document::open()
- Use null-document tasks for non-changing navigable updates and
document unload/destroy to avoid stuck tasks when documents become
non-fully-active
- Defer completely_finish_loading when document has no navigable yet,
and re-trigger post-load steps in activate_history_entry for documents
that completed loading before activation
Co-Authored-By: Shannon Booth <shannon@serenityos.org>
HTMLScriptElement::execute_script() and SVGScriptElement had spin_until
calls waiting for ready_to_run_scripts to become true. The race exists
because load_html_document() resolves the session history signal and
starts the parser in the same deferred_invoke — so the parser can hit a
<script> before update_for_history_step_application() sets the flag.
Instead of spinning, defer parser->run() until the document is ready.
Document gains a m_deferred_parser_start callback that is invoked when
set_ready_to_run_scripts() is called. The callback is cleared before
invocation to avoid reentrancy issues (parser->run() can synchronously
execute scripts). All three document loading paths (HTML, XML, text)
now check ready_to_run_scripts before starting the parser and defer if
needed.
create_document_for_inline_content() (used for error pages) now calls
set_ready_to_run_scripts() before mutating the document, ensuring the
invariant holds for all parser paths.
The spin_until calls are replaced with VERIFY assertions.
HTMLParser::the_end() had three spin_until calls that blocked the event
loop: step 5 (deferred scripts), step 7 (ASAP scripts), and step 8
(load event delay). This replaces them with an HTMLParserEndState state
machine that progresses asynchronously via callbacks.
The state machine has three phases matching the three spin_until calls:
- WaitingForDeferredScripts: loops executing ready deferred scripts
- WaitingForASAPScripts: waits for ASAP script lists to empty
- WaitingForLoadEventDelay: waits for nothing to delay the load event
Notification triggers re-evaluate the state machine when conditions
change: HTMLScriptElement::mark_as_ready, stylesheet unblocking in
StyleElementBase/HTMLLinkElement, did_stop_being_active_document, and
DocumentLoadEventDelayer decrements. NavigableContainer state changes
(session history readiness, content navigable cleared, lazy load flag)
also trigger re-evaluation of the load event delay check.
Key design decisions and why:
1. Microtask checkpoint in schedule_progress_check(): The old spin_until
called perform_a_microtask_checkpoint() before checking conditions.
This is critical because HTMLImageElement::update_the_image_data step
8 queues a microtask that creates the DocumentLoadEventDelayer.
Without the checkpoint, check_progress() would see zero delayers and
complete before images start delaying the load event.
2. deferred_invoke in schedule_progress_check():
I tried Core::Timer (0ms), queue_global_task, and synchronous calls.
Timers caused non-deterministic ordering with the HTML event loop's
task processing timer, leading to image layout tests failing (wrong
subtest pass/fail patterns). Synchronous calls fired too early during
image load processing before dimensions were set, causing 0-height
images in layout tests. queue_global_task had task ordering issues
with the session history traversal queue. deferred_invoke runs after
the current callback returns but within the same event loop pump,
giving the right balance.
3. Navigation load event guard (m_navigation_load_event_guard): During
cross-document navigation, finalize_a_cross_document_navigation step
2 calls set_delaying_load_events(false) before the session history
traversal activates the new document. This creates a transient state
where the parent's load event delay check sees the about:blank (which
has ready_for_post_load_tasks=true) as the active document and
completes prematurely.
This now takes a registry directly. As a temporary stop-gap, the old
method on Document is still here and calls the new one.
We do get a test regression:
"Creating an element in a cloned document and inserting into the
document must not enqueue a custom element upgrade reaction" in
"custom-elements/upgrading.html".
Possibly a spec bug?
The hover invalidation code only tried matching ::before/::after
selectors when has_pseudo_element() returned true, which requires an
existing layout node. A pseudo-element that doesn't exist yet (because
its content is only set by a hover rule) has no layout node, so the
match was skipped and hovering never triggered a style recompute.
Always try ::before/::after selectors during hover invalidation.
Pre-compute per-observer values (root node, root paintable, root
bounds, is_implicit_root, root_is_element) once before the per-target
loop instead of recomputing them for each target.
Add intersection_root_node() which returns GC::Ref<DOM::Node> without
creating GC::Root wrappers. Previously, intersection_root() was called
multiple times per target (in the skip condition check, in
compute_intersection, and again in root_intersection_rectangle inside
compute_intersection), each call creating GC::Root objects that require
heap allocation via new RootImpl.
Pass the pre-computed root bounds and root paintable into
compute_intersection instead of having it call
root_intersection_rectangle() and intersection_root() internally.
For an observer watching N targets, this eliminates roughly 4N heap
allocations per frame.
Per the spec, the observer's [[scrollMargin]] should be applied to
each scroll container's scrollport when walking the containing block
chain. This expands the effective clip rect, allowing targets to be
detected as intersecting before they actually enter the visible area
of the scroll container.
Add a scroll_margin_values() accessor to IntersectionObserver so the
raw LengthPercentage values can be used during intersection computation.
The scroll margin is applied by inflating the scroll container's
padding box rect before clipping the intersection rect against it.
Implement the containing block chain traversal in compute_intersection
(steps 2-3 of the spec algorithm). Walk from the target's paintable box
up through the containing block chain, clipping the intersection rect
against each ancestor that has a content clip (overflow != visible).
This fixes the case where a target is inside an overflow:hidden or
overflow:clip container and pushed below the visible area. Previously,
the intersection ratio was incorrectly non-zero because we only
intersected with the root bounds (viewport), not intermediate
scroll containers.
Also update the scroll container clipping tests to verify the
intersection ratio (which is what compute_intersection affects)
rather than isIntersecting (which per spec is based on targetRect
vs rootBounds, not the clipped intersection rect).
The boolean logic in steps 2-3 of "run the update intersection
observations steps" was incorrect. The code used || between the two
negated skip conditions instead of &&, and the first sub-expression
had its negation inverted.
This caused intersection geometry to be computed (and callbacks fired)
for targets that are not descendants of an explicit element root,
as long as they spatially overlapped the root's bounding rect.
The spec says:
- Step 2: Skip if root is not implicit AND target not in same document.
- Step 3: Skip if root is Element AND target not descendant of root.
The enter condition is NOT(skip2) AND NOT(skip3), but we had
NOT(skip2) OR NOT(skip3) with a wrong negation in the first part.
Add a per-Document cache that maps selector strings to their parsed
SelectorList results. This avoids re-tokenizing and re-parsing the
same selector strings on every call, which is a huge win for pages
that repeatedly call querySelectorAll with the same selectors.
On microsoft.com, where they spam querySelectorAll with the same two
selectors, profiling showed 62% of main thread time was spent
re-parsing selectors. This cache eliminates that entirely for
repeated queries.
Previously, destroyed-document tasks were forced to be runnable to
prevent them from leaking in the task queue. Instead, discard them
during task selection so their callbacks never run with stale state.
This used to cause issues with a couple of `spin_until()`s in the past,
but since we've removed some of them that had to do with the document
lifecycle, let's see if we can stick closer to the spec now.
Instead of immediately firing fullscreenchange, defer that until
WebContent's client has confirmed that it is in fullscreen for the
content. The fullscreenchange is fired by the viewport change, so in
cases where the fullscreen transition is instantaneous (i.e. the
fullscreen state is entered at the exact moment the viewport expands),
the resize event should precede the fullscreenchange event, as the spec
requires.
This fixes the WPT element-request-fullscreen-timing.html test, which
was previously succeeding by accident because we were immediately
fullscreenchange upon requestFullscreen() being called, instead of
following spec and doing the viewport (window) resize in parallel. The
WPT test was actually initially intended to assert that the
fullscreenchange event follows the resize event, but the WPT runner
didn't actually have a different resolution for normal vs fullscreen
viewports, so the resize event doesn't actually fire in their setup. In
our headless mode, the default viewport is 800x600, and the fullscreen
viewport is 1920x1080, so we do fire a resize event when entering
fullscreen. Therefore, that imported test is reverted to assert that
the resize precedes the fullscreenchange.
We were conflating elements being the active element and elements being
activated. The :active pseudo class is supposed to be based on whether
an element will have its activation behavior run upon a button being
released.
Store whether an element is being activated as a flag that is set/reset
by EventHandler.
Doing this allows label elements to visually activate their control
without doing a weird paintable hack, so the Labelable classes have
been yeeted.
Rename DocumentDestructionState into a more generic
DocumentLifecycleState so it can be reused for the document unloading
logic. Instead of using ::spin_until(), use a callback mechanism to run
code once all child navigables are unloaded.
1. unload_a_document_and_its_descendants() now follows the spec
algorithm structure: recursively unload child navigables via queued
tasks (step 4), wait for them (step 5), then queue this document's
own unload as a separate task (step 6). Previously, this was
flattened into a single spin that unloaded all descendants and the
document together, followed by a non-spec call to
destroy_a_document_and_its_descendants().
2. unload() step 19 now calls destroy() when the document is not
salvageable, as the spec requires. Previously this was a no-op with a
comment deferring to unload_a_document_and_its_descendants().
3. destroy_top_level_traversable() step 2 now calls
destroy_a_document_and_its_descendants() instead of destroy().
The iframe-unloading-order test, which exercises named iframe access
during unload handlers (the scenario the previous logic was designed to
protect), still passes.
Fixes#7825
Replace per-node heap-allocated AtomicRefCounted
AccumulatedVisualContext objects with a single contiguous Vector inside
AccumulatedVisualContextTree. All nodes for a frame are now stored in
one allocation, using type-safe VisualContextIndex instead of RefPtr
pointers.
This reduces allocation churn, improves cache locality, and opens the
door for future snapshotting of visual context state — similar to how
scroll offsets are snapshotted today.
The style of an element depends on it's navigable's viewport size which
in turn depends on the navigable's container's style - so if requires a
style update then so does the original element.
Introduce Document::update_layout_if_needed_for_node() which only calls
update_layout() when the node is connected. Use it at all call sites
that query layout metrics (offsets, client dimensions, image size, SVG
bounding box, etc.) so disconnected elements no longer trigger an
unnecessary layout.
With per-paintable display list command caching now in place, the
separate paint-only properties resolution phase is no longer needed.
Resolution now happens inline during painting and its cost is amortized
since it only runs on cache miss.
Move all property resolution to point of consumption:
- is_visible() and visible_for_hit_testing() compute on the fly
- Filter resolution moved to assign_accumulated_visual_contexts()
- Border radii, outlines computed on access
- Box shadows, backdrop filter resolved inline during painting
- Background resolution moved into paint_background()
- Mask resolution moved to StackingContext::paint()
- Text fragment and SVG stroke properties resolved during painting
Cache the display list commands produced by each PaintableBox's paint()
on a per-phase basis. On subsequent display list rebuilds, if a
paintable's cache is still valid, replay the recorded commands directly
— skipping paint() and all the property resolution it entails.
Besides saving time on property resolution, this also enables Skia to
reuse path tessellation results across frames — e.g. border paths are
preserved in the cache and don't need to be re-tessellated on every
repaint.
Rename Document::set_needs_display() to set_needs_repaint() and make it
private. External callers must now go through Node/Paintable which
route the request to the document internally.
Fix one existing misuse in AnimationEffect that was calling
document-level set_needs_display() instead of routing through the
target element's paintable.
This is preparation for per-paintable display list command caching:
repaint requests must go through specific paintables so their cached
command lists can be invalidated.
* Don't publicly expose methods that are only used internally.
* Modernize comment style (wrap at 120 chars, use NB for our notes).
* Change the stringifier for RequestFullscreenError to return a UTF-16
string. We were allocating a String, then transcoding it to UTF-16.
* Give helper methods clearer names, e.g.:
fullscreen_has_error_check -> is_element_allowed_to_enter_fullscreen
Throwaway LayoutState instances used for intrinsic sizing should not
access nodes outside the laid-out subtree. Make this explicit by setting
a subtree root on each throwaway state, pre-populating only the
immediate containing block, and using try_get() for any ancestor
lookups — treating unavailable ancestors as indefinite rather than
silently populating them with incorrectly-resolved values.
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.
