In this commit we have optimized the handling of scroll offsets and
clip rectangles to improve performance. Previously, the process
involved multiple full traversals of the paintable tree before each
repaint, which was highly inefficient, especially on pages with a
large number of paintables. The steps were:
1. Traverse the paintable tree to identify all boxes with scrollable or
clipped overflow.
2. Gather the accumulated scroll offset or clip rectangle for each box.
3. Perform another traversal to apply the corresponding scroll offset
and clip rectangle to each paintable.
To address this, we've adopted a new strategy that separates the
assignment of the scroll/clip frame from the refresh of accumulated
scroll offsets and clip rectangles, thus reducing the workload:
1. Post-relayout: Identify all boxes with overflow and link each
paintable to the state of its containing scroll/clip frame.
2. Pre-repaint: Update the clip rectangle and scroll offset only in the
previously identified boxes.
This adjustment ensures that the costly tree traversals are only
necessary after a relayout, substantially decreasing the amount of work
required before each repaint.
Before this change, `set_needs_to_resolve_paint_only_properties()` was
only called after style invalidation. However, since relayout can be
triggered independently from style invalidation, we need to ensure that
paint-only properties are updated in that case too.
This check has been if (false && stuff) for quite a while, since the
transition to Navigables. No one updates the BrowsingContext's session
history, so the check for it having an about blank document and only an
about blank document is always false.
When an element with an ID is added to or removed from the DOM, or if
an ID is added, removed, or changed, then we must reset the form owner
of all form-associated elements who have a form attribute.
We do this in 2 steps, using the DOM document as the messenger to handle
these changes:
1. All form-associated elements with a form attribute are stored on the
document. If the form attribute is removed, the element is removed
from that list as well.
2. When a DOM element with an ID undergoes any of the aforementioned
changes, it notifies the document of the change. The document then
forwards that change to the stored form-associated elements.
Use the [FlyString] extended attribute to allow these functions to take
an Optional<FlyString> directly, allowing us to tidy up some conversions
from Optional<String>.
Fetching the viewport rect is currently somewhat expensive, since it
requires finding the navigable the document is active in.
We can avoid the cost of repeated calls by simply allowing StyleComputer
to cache the viewport rect at the start of style computation.
The entire subtree of an element with display:none is irrelevant for
purposes of layout and/or paint invalidation.
We now simply ignore invalidation triggers inside such subtrees.
This avoids a *lot* of redundant busywork when running CSS animations
inside not-even-rendered content. As an example, this avoids repainting
YouTube embeds repeatedly due to animating-but-hidden progress
indicators.
Note that the subtree *root* (i.e the `display:none` element itself)
still gets to trigger invalidation, since we may need to rebuild the
layout tree when the `display` property changes.
This stopped being called for anything without a navigable container
after 76a97d8, due to the early return. This broke SVG <use> elements
that reference elements defined later in the document.
So far, we always call make_active() before update_readiness
(Complete), but this will soon not be the case once we implement the
spec document-loading algorithms.
Co-authored-by: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
This change fixes a bug with running tests where, if one of the
previous tests changes the scroll position, all subsequent tests that
rely on the scroll position will fail. This is because the headless
browser never resets the viewport offset.
This commit un-deprecates DeprecatedString, and repurposes it as a byte
string.
As the null state has already been removed, there are no other
particularly hairy blockers in repurposing this type as a byte string
(what it _really_ is).
This commit is auto-generated:
$ xs=$(ack -l \bDeprecatedString\b\|deprecated_string AK Userland \
Meta Ports Ladybird Tests Kernel)
$ perl -pie 's/\bDeprecatedString\b/ByteString/g;
s/deprecated_string/byte_string/g' $xs
$ clang-format --style=file -i \
$(git diff --name-only | grep \.cpp\|\.h)
$ gn format $(git ls-files '*.gn' '*.gni')
With this change, Document now always has a Web::Page. This means we no
longer rely on the breakable link between Document and BrowsingContext
to find a relevant Web::Page.
Fixes#22290
This change fixes GC-leak caused by following mutual dependency:
- SVGDecodedImageData owns JS::Handle for Page.
- SVGDecodedImageData is owned by visited objects.
by making everything inherited from HTML::DecodedImageData and
ListOfAvailableImages to be GC-allocated.
Generally, if visited object has a handle, very likely we leak
everything visited from object in a handle.
No functional impact intended. This is just a more complicated way of
writing what we have now.
The goal of this commit is so that we are able to store the 'name' of a
pseudo element for use in serializing 'unknown -webkit-
pseudo-elements', see:
https://www.w3.org/TR/selectors-4/#compat
This is quite awkward, as in pretty much all cases just the selector
type enum is enough, but we will need to cache the name for serializing
these unknown selectors. I can't figure out any reason why we would need
this name anywhere else in the engine, so pretty much everywhere is
still just passing around this raw enum. But this change will allow us
to easily store the name inside of this new struct for when it is needed
for serialization, once those webkit unknown elements are supported by
our engine.
`<iframe>` and `<img>` tags share the same spec for several aspects of
lazy-loading: how the `loading` attribute works, the "will lazy load
element" steps, and a member for storing the lazy-load resumption
steps. So let's share the implementation by using a base class.
This mostly involves moving things around. However, we also change the
`start_intersection_observing_a_lazy_loading_element()` method to take
a LazyLoadingElement, and operate on one, instead of always casting to
HTMLImageElement.
We do unfortunately have to do some shenanigans to make the cast work,
by adding a virtual function stub in DOM::Element.
