The DOMParsing spec is in the process of being merged into the HTML one,
gradually. The linked spec change moves XMLSerializer, but many of the
algorithms are still in the DOMParsing spec so I've left the links to
those alone.
I've done my best to update the GN build but since I'm not actually
using it, I might have done that wrong.
Corresponds to 2edb8cc7ee
All necessary invalidations are issued while invalidating animated
style. There is no need to drop display list simply because there are
some animations that might need an update.
We set the page's focused navigable upon mouse-down events from the UI.
However, we neglected to ever clear that focused navigable upon events
such as subsequent page navigations. This left the page with a stale
reference to a no-longer-active navigable. The effect was that any key
events from the UI would not be sent to the new page until either the
reference was collected by GC, or another mouse-down event occurred.
In the test added here, without this fix, the text sent to the input
element would not be received, and the change event would not fire.
Instead of marking all nodes in the subtree for style recalculation,
including subtrees of subsequent siblings, we can fall back to the
default invalidation path, which is optimized to skip siblings
unaffected by sibling selectors.
Makes scrolling on https://frame.work/pl/en/about go a lot smoother.
This commit implements the main "render blocking" behavior for link
elements, drastically reducing the amount of FOUC (flash of unstyled
content) we subject our users to.
The document will now block rendering until linked style sheets
referenced by parser-created link elements have loaded (or failed).
Note that we don't yet extend the blocking period until "critical
subresources" such as imported style sheets have been downloaded
as well.
This change fixes a bug that can be reproduced with the following steps:
```js
const iframe = document.createElement("iframe");
document.body.appendChild(iframe);
iframe.contentWindow.location.href = ("http://localhost:8080/demo.html");
```
These steps are executed in the following order:
1. Create iframe and schedule session history traversal task that adds
session history entry for the iframe.
2. Generate navigation id for scheduled navigation to
`http://localhost:8080/demo.html`.
3. Execute the scheduled session history traversal task, which adds
session history entry for the iframe.
4. Ooops, navigation to `http://localhost:8080/demo.html` is aborted
because addings SHE for the iframe resets the navigation id.
This change fixes this by delaying all navigations until SHE for a
navigable is created.
We hold a raw pointer to the mouse selection target, which is a mixin-
style class inherited only by JS::Cell classes. By not visiting this
object, we sometime had a dangling reference to it after it had been
garbage collected.
Previously, they would stay open for the entire WebContent lifetime,
or until the server closed the connection. This was particularly
noticeable on collaborative websites/games such as
https://jigsawpuzzles.io/, where the user using Ladybird would stick
around even after they had navigated away.
The spec changes seem to mostly be about introducing a TrustedHTML type
which we do not yet support, so we have a couple of FIXMEs.
TrustedTypes::InjectionSink is an attempt at matching the spec, but it's
not entirely clear to me how it should work. I'm sure it'll get
revisited once we start implementing trusted types.
Our own Inspector differs from most other DevTools implementations with
regard to highlighting DOM nodes as you hover elements in the inspected
DOM tree. In other implementations, as you change the hovered node, the
browser will render a box model overlay onto the page for that node. We
currently don't do this; we wait until you click the node, at which
point we both paint the overlay and inspect the node's properties.
This patch does not change that behavior, but separates the IPCs and
internal tracking of inspected nodes to support the standard DevTools
behavior. So the DOM document now stores an inspected node and a
highlighted node. The former is used for features such as "$0" in the
JavaScript console, and the latter is used for the box model overlay.
Our Inspector continues to set these to the same node.
This reduces the number of `.cpp` files that need to be recompiled when
one of the below header files changes as follows:
CSS/ComputedProperties.h: 1113 -> 49
CSS/ComputedValues.h: 1120 -> 209
Analysis of selectors on modern websites shows that the `:hover`
pseudo-class is mostly used in the subject position within relatively
simple selectors like `.a:hover`. This suggests that we could greatly
benefit from segregating them by id/class/tag name, this way reducing
number of selectors tested during hover style invalidation.
With this change, hover invalidation on Discord goes down from 70ms to
3ms on my machine. I also tested GMail and GitHub where this change
shows nice 2x-3x speedup.
This is required to store Content Security Policies, as their
Directives are implemented as subclasses with overridden virtual
functions. Thus, they cannot be stored as generic Directive classes, as
it'll lose the ability to call overridden functions when they are
copied.
Regressed in 036327332f.
This commit moves the optimization a little later in replaceData(),
still avoiding relayout (the important part).
Recovers 480 points on WPT. :^)
If selector does not have any descendant combinators then we know for
sure it won't be filtered out by ancestor filter, which means there is
no need to check for it.
This change makes hover style invalidation go faster on Discord where
with this change we spend 4-5% in `should_reject_with_ancestor_filter()`
instead of 20%.
Allows us to avoid invalidating layout when CharacterData didn't change.
Results in visible improvement on Discord that continuously invokes
this function with the same data, which previously resulted in relayout
on every frame.
Before this change, we did the following:
1. Created a bitmap with the matching state for each rule containing
`:hover`.
2. Changed the actively hovered element in the document.
3. Created another bitmap with the matching state for each rule
containing `:hover`.
With this change, we iterate rule by rule and compare the matching
state. This allows us to break early once we find the first rule whose
matching state changes after the hovered element update. Additionally,
this removes the need to allocate a bitmap.
Instead of using `has_pseudo_elements()` that iterates over all pseudo
elements, only check if `::before` or `::after` are present.
Before this change, `has_pseudo_elements()` was 10% of profiles on
Discord while now it's 1-2%.
...in inherited style update. Instead of comparing old absolutized value
with new non-absolutized value, we should wait until
`absolutize_values()` and then compare old and new values, when both are
absolutized.
Improves performance on pages with GitHub action logs where previously
we had to invalidate layout after hover style recalculation, because
there was `margin-left: 1rem`.
MediaQueryList will now remember if a state change occurred when
evaluating its match state. This memory can then be used by the document
later on when it's updating all queries, to ensure that we don't forget
to fire at least one change event.
This also required plumbing the system visibility state to initial
about:blank documents, since otherwise they would be stuck in "hidden"
state indefinitely and never evaluate their media queries.
Instead of checking all elements in a document for containment in
`:has()` invalidation set, we could narrow this down to ancestors and
ancestor siblings, like we already do for subject `:has()` invalidation.
This change brings great improvement on GitHub that has selectors with
non-subject `:has()` and sibling combinators (e.g., `.a:has(.b) ~ .c`)
which prior to this change meant style invalidation for whole document.
This allows us to inspect its properties. To avoid wasted work, we only
compute and cache the properties if the originating element was, or is,
displaying as a list item.
This commit changes the strategy for updating inherited styles. Instead
of marking all potentially affected nodes during style invalidation, the
decision is now made on-the-fly during style recalculation. Child nodes
will only have their inherited styles recalculated if their parent's
properties have changed.
On Discord this allows to 1000x reduce number of nodes with recalculated
inherited style.
`invalidate_style()` already tries to avoid scheduling invalidation for
`:has()` by checking result of `may_have_has_selectors()`, but it might
still result in unnecessary work because `may_have_has_selectors()`
does not force building of rules cache. This change adds
`have_has_selectors()` that forces building of rules cache and is
invoked in `update_style()` to double-check whether we actually need to
process scheduled `:has()` invalidations.
This allows to skip ~100000 ancestor traversals on this WPT test:
https://wpt.live/html/select/options-length-too-large.html
