The paintable tree structure more closely matches the painting order
when fragments are owned by corresponding inline paintables. This
change does not affect the layout tree, as it is more convenient for
layout purposes to have all fragments owned by a block container in
one place.
Additionally, this improves performance significantly on pages with
many fragments, as we no longer have to walk the ancestor chain up
to the closest block container to determine if a fragment belongs
to an inline paintable.
Instead of trying to be clever and detaching the paint tree lazily,
just detach all paintables from both DOM and layout tree when building
and committing respectively.
Switch over from deprecated_attribute to attribute, and reuse the result
of this lookup for both checking whether that attribute exists - and for
retrieving the value of that attribute when we need it.
Rather than resolving the text-shadow each time painting commands are
recorded, we can resolve it once during the layout commit and save the
resolved values in paintable fragments. This is also step towards
getting rid of layout node pointer in paintable fragment.
If the entire document is invalidated, we know a full style update is
coming soon, and there's no need to try and invalidate a smaller part.
This avoids a *lot* of work on some pages. As an example, we are able to
skip ~1.5 million style invalidations on https://html.spec.whatwg.org/
This is a part of refactoring towards making the paintable tree
independent of the layout tree. Now, instead of transferring text
fragments from the layout tree to the paintable tree during the layout
commit phase, we allocate separate PaintableFragments that contain only
the information necessary for painting. Doing this also allows us to
get rid LineBoxes, as they are used only during layout.
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>.
`JsonValue::to_byte_string` has peculiar type-erasure semantics which is
not usually intended. Unfortunately, it also has a very stereotypical
name which does not warn about unexpected behavior. So let's prefix it
with `deprecated_` to make new code use `as_string` if it just wants to
get string value or `serialized<StringBuilder>` if it needs to do proper
serialization.
Instead of spawning these processes from the WebContent process, we now
create them in the Browser chrome.
Part 1/N of "all processes are owned by the chrome".
This patch makes a few changes to the way we calculate line-height:
- `line-height: normal` is now resolved using metrics from the used
font (specifically, round(A + D + lineGap)).
- `line-height: calc(...)` is now resolved at style compute time.
- `line-height` values are now absolutized at style compute time.
As a consequence of the above, we no longer need to walk the DOM
ancestor chain looking for line-heights during style computation.
Instead, values are inherited, resolved and absolutized locally.
This is not only much faster, but also makes our line-height metrics
match those of other engines like Gecko and Blink.
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.
We have two known PlatformObjects that need to implement some of the
behavior of LegacyPlatformObjects to date: Window, and HTMLFormElement.
To make this not require double (or virtual) inheritance of
PlatformObject, move the behavior of LegacyPlatformObject into
PlatformObject. The selection of LegacyPlatformObject behavior is done
with a new bitfield of feature flags instead of a dozen virtual
functions that return bool. This change simplifies every class involved
in the diff with the notable exception of Window, which now needs some
ugly const casts to implement named property access.
When the caller of NumericCalculationNode::resolve() does not provide
a percentage_basis, it expects the method to return a raw percentage
value.
Fixes crashing on https://discord.com/login
The grammar which we implemented did not match the spec, resulting in us
rejecting background positions which contained 'center' position
keywords.
Fixes: #22401
Until now, we had implemented flex container sizing by awkwardly doing
exactly what the spec said (basically having FFC size the container)
despite that not really making sense in the big picture. (Parent
formatting contexts should be responsible for sizing and placing their
children)
This patch moves us away from the Flexbox spec text a little bit, by
removing the logic for sizing the flex container in FFC, and instead
making sure that all formatting contexts can set both width and height
of flex container children.
This required changes in BFC and IFC, but it's actually quite simple!
Width was already not a problem, and it turns out height isn't either,
since the automatic height of a flex container is max-content.
With this in mind, we can simply determine the height of flex containers
before transferring control to FFC, and everything flows nicely.
With this change, we can remove all the virtuals and FFC logic for
negotiating container size with the parent formatting context.
We also don't need the "available space for flex container" stuff
anymore either, so that's gone as well.
There are some minor diffs in layout test results from this, but the
new results actually match other browsers more closely, so that's fine.
This should make flex layout, and indeed layout in general, easier to
understand, since this was the main weird special case outside of
BFC/IFC where a formatting context delegates work to its parent instead
of the other way around. :^)
Many sites load application/json and application/ld+json
content with script elements, so this debug line shows
up on a lot of sites and is not informative.
On platinenmacher.tech there is a document without a window. During
size attribute parsing the window pointer is dereferenced which
causes a crash. This checks for the window to be actually there
before dereferencing.
As the spec points out:
> Note that a pair of keywords can be reordered while a combination of
> keyword and length or percentage cannot. So center left is valid while
> 50% left is not.
This was a bug in our implementation of alternative 2 of css-values-3,
resulting in the following CSS failing to be parsed:
`background-position: center right;`
This commit fixes the issue as part of an update of the parsing to
css-values-4. As far as I can tell, the grammar is equivalent - but
simpler to implement due to the lack of optional values.
The fix for this issue is also as part of alternative 2 parsing in the
new grammar.
Progress towards: #22401
Instead of serializing two calc() values to String and then comparing
those strings, we can now compare calc() values by actually traversing
their internal CalculationNode tree.
This makes style recomputation faster on pages with lots of calc()
values since it's now much cheaper to check whether a property with
some calc() value actually changed.
Previously, these were clipped by the RecordingPainter, which used the
path's bounding box (which in this case is zero width or height). The
fix is to expand the bounding box by the stroke width.
Fixes#22661
Note: This is unrelated to any recent LibGfx changes :^)
Before this change, we used the wrong insertion point for flex items
in reverse layouts with `justify-content: normal`. This caused flex
items to overflow the flex containers "backwards" from the start edge.
