There was no need to use FlyString for error messages, and it just
caused a bunch of churn since these strings typically only existed
during the lifetime of the error.
This way we don't have to allocate separate vector with both scroll and
sticky frame that is used for display list player (scroll and sticky
frames share id pool), so player could access offset by frame id.
No behavior change.
While Origin is defined in the HTML spec - this leaves us with quite an
awkward relationship as the URL spec makes use of AO's from what is
defined in the HTML spec.
To simplify this factoring, relocate Origin into LibURL.
Implements https://github.com/whatwg/html/pull/10007 which basically
moves style, layout and painting from HTML processing task into HTML
task with "rendering" source.
The biggest difference is that now we no longer schedule HTML event loop
processing whenever we might need a repaint, but instead queue a global
rendering task 60 times per second that will check if any documents
need a style/layout/paint update.
That is a great simplification of our repaint scheduling model. Before
we had:
- Optional timer that schedules animation updates 60 hz
- Optional timer that schedules rAF updates
- PaintWhenReady state to schedule a paint if navigable doesn't have a
rendering opportunity on the last event loop iteration
Now all that is gone and replaced with a single timer that drives
repainting at 60 hz and we don't have to worry about excessive repaints.
In the future, hard-coded 60 hz refresh interval could be replaced with
CADisplayLink on macOS and similar API on linux to drive repainting in
synchronization with display's refresh rate.
update_layout() need to be invoked before checking if layout node is
present, because layout not being updated might be the reason why layout
node doesn't exist yet.
The expensive part of creating a segmenter is doing the locale and UCD
data lookups at creation time. Instead of doing this once per text node,
cache the segmenters on the document, and clone them as needed (cloning
is much, much cheaper).
On a profile loading Ladybird's GitHub repo, the following hot methods
changed as follows:
ChunkIterator ctor: 6.08% -> 0.21%
Segmenter factory: 5.86% -> 0%
Segmenter clone: N/A -> 0.09%
This patch implements `Range::getClientRects` and
`Range::getBoundingClientRect`. Since the rects returned by invoking
getClientRects can be accessed without adding them to the Selection,
`ViewportPaintable::recompute_selection_states` has been updated to
accept a Range as a parameter, rather than acquiring it through the
Document's Selection.
With this change, the following tests now pass:
- wpt[css/cssom-view/range-bounding-client-rect-with-nested-text.html]
- wpt[css/cssom-view/DOMRectList.html]
Note: The test
"css/cssom-view/range-bounding-client-rect-with-display-contents.html"
still fails due to an issue with Element::getClientRects, which will
be addressed in a future commit.
Before this change, a formatting context was responsible for layout of
absolutely positioned boxes whose FC root box was their parent (either
directly or indirectly). This only worked correctly when the containing
block of the absolutely positioned child did not escape the FC root.
This is because the width and height of an absolutely positioned box are
resolved based on the size of its containing block, so we needed to
ensure that the containing block's layout was completed before laying
out an absolutely positioned box.
With this change, the layout of absolutely positioned boxes is delayed
until the FC responsible for the containing block's layout is complete.
This has affected the way we calculate the static position. It is no
longer possible to ask the FC for a box's static position, as this FC's
state might be gone by the time the layout for absolutely positioned
elements occurs. Instead, the "static position rectangle" (a concept
from the spec) is saved in the layout state, along with information on
how to align the box within this rectangle when its width and height are
resolved.
FormattingContext::run() does not allow reentrancy, so it's safe to
save and access layout mode from FC object. This avoids need to drill it
through methods of a formatting context and makes it clear that this
value could never be changed after FC construction.
Root formatting context box is passed into constructor and saved in FC,
so it's possible to access it from there instead of passing the same
box into run().
You can now build with STYLE_INVALIDATION_DEBUG and get a debug stream
of reasons why style invalidations are happening and where.
I've rewritten this code many times, so instead of throwing it away once
again, I figured we should at least have it behind a flag.
This API is a relic from the time when it was important for objects to
have easy access to the Window, and to know it was the global object.
We now have more spec-related concepts like relevant_global_object and
current_global_object to pull the Window out of thin air.
Calls to `Document::set_needs_display()` and
`Paintable::set_needs_display()` now invalidate the display list by
default. This behavior can be changed by passing
`InvalidateDisplayList::No` to the function where invalidating the
display list is not necessary.
Use offset from ScrollFrame which is an actual value a box is shifted by
while painting.
Also change `update_paint_and_hit_testing_properties_if_needed()` to
refresh scroll frames state, because `getBoundingClientRect()` now
depends on them.
Fixes wrong file tree sidebar location and excessive layout
invalidations caused by some miscalculation on JS-side when wrong
bounding client rect is provided on Github PR pages like
https://github.com/LadybirdBrowser/ladybird/pull/1232/files
Sticky positioning is implemented by modifying the algorithm for
assigning and refreshing scroll frames. Now, elements with
"position: sticky" are assigned their own scroll frame, and their
position is refreshed independently from regular scroll boxes.
Refreshing the scroll offsets for sticky boxes does not require display
list invalidation.
A separate hash map is used for the scroll frames of sticky boxes. This
is necessary because a single paintable box can have two scroll frames
if it 1) has "position: sticky" and 2) contains scrollable overflow.
`BrowsingContext::m_parent` has been removed from the spec,
and previously `m_parent` was always null.
`BrowsingContext::is_top_level` was already always returning
true before because of that, and the updated spec algorithm
causes assertions to fail.
This fixes the following example:
```html
<a href="about:blank" target="test">a
<iframe name="test">
```
clicking the link twice no longer causes it to open in a new tab.
...if only the scroll offset is updated.
Currently, on any document with a large amount of content, the process
of building a display list is often more expensive than its
rasterization. This is because the amount of work required to build a
display list is proportional to the size of the paintable tree, whereas
rasterization only occurs for the portion visible in the viewport.
This change is the first step toward improving this process by caching
the display list across repaints when neither style nor layout requires
invalidation. This means that repainting while scrolling becomes
significantly less expensive, as we only need to reapply the scroll
offsets to the existing display list.
The performance improvement is especially visible on pages like
https://ziglang.org/documentation/master/ or
https://www.w3.org/TR/css-grid-2/
While introducing clip and scroll frame trees, I made a mistake by
assuming that the paintable tree includes boxes from nested navigables.
Therefore, this comment in the code was incorrect, and clip/scroll
frames were simply not assigned for iframes:
// NOTE: We only need to refresh the scroll state for traversables
// because they are responsible for tracking the state of all
// nested navigables.
As a result, anything with "overflow: scroll" is currently not
scrollable inside an iframe
This change fixes that by ensuring clip and scroll frames are assigned
and refreshed for each navigable. To achieve this, I had to modify the
display list building process to record a separate display list for each
navigable. This is necessary because scroll frame ids are local to a
navigable, making it impossible to call
`DisplayList::apply_scroll_offsets()` on a display list that contains
ids from multiple navigables.
For the SVG <use> element, we want to support loading HTML documents
that have a SVG element inside of it pointed to by the URL fragment.
In this situation we would need to fetch and parse the entire document
in SharedImageRequest (so that we can still cache the SVGs). Rename
SharedImageRequest to SharedResourceRequest to make the class a little
more generic for future usecases.
To avoid expensive lookups, we now cache a weak pointer from document to
the last known node navigable. Before using the cache, we validate that
the document is still the navigable's active document.
Navigables are re-used for navigations within the same tab. Its current
ownership of the cursor position is a bit ad-hoc, so nothing in the spec
indicates when to reset the cursor, nor do we manually do so. So when a
cursor update happens on one page, that cursor is retained on the next
page.
Instead, let's have the document own the cursor. Each navigation results
in a new document, thus we don't need to worry about resetting cursors.
This also makes many of the callsites feel nicer. We were previously
often going from the node, to the document, to the navigable, to the
cursor. This patch removes the navigable hop.
We explicitly stopped visting the map of documents to console clients in
commit 44659f2f2a to avoid keeping the
document alive. However, if nothing else visits the console clients, we
may set the top-level console client to a client that has been garbage
collected.
So instead of storing this map, just store the console client on the
document itself. This will allow the document to visit its client.
