This patch does three things:
- Factors out the code that determines whether a box will create a new
formatting context for its children (and which type of context)
- Uses that code to mark all formatting context roots in layout tree
dumps. This makes it much easier to follow along with layout since
you can now see exactly where control is transferred to a new
formatting context.
- Rebaselines all existing layout tests, since the output format has
changed slightly.
It returns a PaintableBox (a PaintableWithLines, to be specific), not a
'PaintBox'. paintable_box() without the cast is already available
through BlockContainer's Box base class, we don't need to shadow it.
DeprecatedFlyString relies heavily on DeprecatedString's StringImpl, so
let's rename it to A) match the name of DeprecatedString, B) write a new
FlyString class that is tied to String.
This fixes a few sizing issues too. The page size is now correct in most
cases! \o/
We get to remove some of the `to_type<>()` shenanigans, though it
reappears in some other places.
This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.
One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
The ::placeholder pseudo element was added in commit 1fbad9c, but the
total number of pseudo elements was not updated. Instead of this manual
bookkeeping, add a dummy value at the end of the enumeration for the
count.
When matching selectors in HTML documents, we know that all the elements
have lowercase local names already (the parser makes sure of this.)
Style sheets still need to remember the original name strings, in case
we want to match against non-HTML content like XML/SVG. To make the
common HTML case faster, we now cache a lowercase version of the name
with each type/class/id SimpleSelector.
This makes tag type checks O(1) instead of O(n).
These will be needed for styling progress bars, sadly this can
only be done with these non-standard selectors. These are, hovever,
in use on real sites such as https://rpcs3.net/compatibility.
Each of these strings would previously rely on StringView's char const*
constructor overload, which would call __builtin_strlen on the string.
Since we now have operator ""sv, we can replace these with much simpler
versions. This opens the door to being able to remove
StringView(char const*).
No functional changes.
We already had the CSSRule::Type enum, but the values were not aligned
with the CSSOM spec. This patch takes care of that, and then exposes
the type of a CSSRule to JavaScript via the "type" attribute.
This is used to skip downloading fonts in formats that we don't support.
Currently we only support TTF as far as I am aware.
The parts of a `src` are in a fixed order, unusually, which makes the
parsing more nesty instead of loopy.
We now distribute the line-height evenly between the space above and
below inline-level boxes. This noticeably improves our baseline
alignment in many cases.
Note that the "vertical-align: <length>" case is quite awkward, as the
extra height added by the offset baseline must count towards the line
box height.
There's a lot of room for improvement here, but this makes the buckets
container on Acid3 show up in the right place, with the right size.
Now that we use a Variant for the SimpleSelector's data, we don't need
to instantiate empty structs or variables for the types that aren't
used, and so we can remove `PseudoElement::None`,
`PsuedoClass::Type::None` and `Attribute::MatchType::None`.
Also, we now always initialize a SimpleSelector with a type, so
`SimpleSelector::Type::Invalid` can go too.
This doesn't have parsing support for multiple languages in the same
selector. Support for language subcodes is not great either. But it
does do the basics.
In Selectors level 4, `:nth-child()` and `:nth-last-child()` can both
optionally take a selector-list argument. This selector-list acts as a
filter, so that only elements matching the list are counted. For
example, this means that the following are equivalent:
```css
:nth-child(2n+1 of p) {}
p:nth-of-type(2n+1) {}
```
Let's make it very clear that these are *computed* values, and not at
all the specified values. The specified values are currently discarded
by the CSS cascade algorithm.
BlockContainer paint boxes are the only ones that have line boxes
associated, so let's not waste memory on line boxes in all the other
types of boxes.
This also adds Layout::Box::paint_box() and the more tightly typed
Layout::BlockContainer::paint_box() to get at the paint box from the
corresponding layout box.
The "paintable" state in Layout::Box was actually not safe to access
until after layout had been performed.
As a first step towards making this harder to mess up accidentally,
this patch moves painting information from Layout::Box to a new class:
Painting::Box. Every layout can have a corresponding paint box, and
it holds the final used metrics determined by layout.
The paint box is created and populated by FormattingState::commit().
I've also added DOM::Node::paint_box() as a convenient way to access
the paint box (if available) of a given DOM node.
Going forward, I believe this will allow us to better separate data
that belongs to layout vs painting, and also open up opportunities
for naturally invalidating caches in the paint box (since it's
reconstituted by every layout.)
