When a button should use flex for alignment and also has ::before
and/or ::after, we previously did the following:
1. Prepended/appended the button's children with boxes for
pseudo-elements.
2. Replaced the button's direct children with a flex container that
contains its children.
As a result, the generated boxes for ::before/::after ended up as
children of the generated flex item, instead of being direct children
of the button layout box as they were supposed to be.
This change reverses these steps, ensuring that boxes for
pseudo-elements are generated only after modifications inside the
button layout are completed.
When modifying the button layout during tree building to use flex for
vertical alignment, let's explicitly set the button box's children to
be non-inline. It doesn't make sense to layout the button as an IFC
when its only child is a flex container.
The final used values for these properties is stored in the layout node,
so we need to make sure they are propagated there as well when doing
table box fixup.
Using flex layout inside button solves the issue with wrongly calculated
height when it has: pseudo element and whitespaces inside.
Also using flex instead of a table layout allows for the same vertical
alignment but with fewer layout nodes: a flex container and anonymous
wrapper for content instead of a table wrapper, table, row, and cell.
Before this change, we were creating a new anonymous flex item for every
inline-level child of a flex container, even when we had a sequence of
inline-level children.
The fix here is to simply keep putting things in the last child of the
flex container, if that child is already an anonymous flex item.
We were relying on the table fixup algorithm to insert the missing table
row, which fails to do so when we only have an image in the button.
While that might be a problem with the table fixup algorithm, we should
build a correct layout tree explicitly anyway.
Fixes crashes on GitHub.
Stop worrying about tiny OOMs. Work towards #20449.
While going through these, I also changed the function signature in many
places where returning ThrowCompletionOr<T> is no longer necessary.
This fixes the "last changed" time for files on GitHub. Note that this
appears to be in accordance with the shadow DOM specification, but I
can't find a line that neatly says it. Though on Google's post about
shadow DOM v1 it says:
> "the element's shadow DOM is rendered in place of its children."
https://web.dev/shadowdom-v1/#creating-shadow-dom-for-a-custom-element
When toggling `display: none` on an element, it can go from having a
layout subtree to not having one. In the `none` case, we were previously
leaving stale layout nodes hanging off DOM nodes in the subtree.
These layout nodes could be queried for outdated information and
probably other things that we shouldn't allow.
Fix this by having TreeBuilder prune any old layout nodes hanging off
nodes in a subtree after its subtree root doesn't produce a layout node.
This change makes tree builder omit elements with "display: contents"
from the layout tree during construction. Their child elements are
instead directly appended to the parent element in layout tree.
On style update, we have to preserve the invariant established when we
built the layout tree - some properties are applied to the table wrapper
and the table box values are reset to their initial values.
This also ensures that the containing block of a table box is always a
table wrapper, which isn't the case if we set absolute position on the
box instead of the wrapper.
Fixes#19452.
Solves conflict in layout tree "type system" when elements <label> (or
<button>) can't have `display: table` because Box can't be
Layout::Label (or Layout::ButtonBox) and Layout::TableBox at the same
time.
From spec https://drafts.csswg.org/css-grid/#grid-items:
"Each in-flow child of a grid container becomes a grid item, and each
child text sequence is wrapped in an anonymous block container grid
item."
Fixes the problem that text sequences inside grid containers are
ignored and not displayed.
We now create a flex container inside the input element's UA shadow tree
and add the placeholder and non-placeholder text as flex items (wrapped
in elements whose style we can manipulate).
This fixes the visual glitch where the placeholder would appear below
the bounding box of the input element. It also allows us to align the
text vertically inside the input element (like we're supposed to).
In order to achieve this, I had to make two small architectural changes
to layout tree building:
- Elements can now report that they represent a given pseudo element.
This allows us to instantiate the ::placeholder pseudo element as an
actual DOM element inside the input element's UA shadow tree.
- We no longer create a separate layout node for the shadow root itself.
Instead, children of the shadow root are treated as if they were
children of the DOM element itself for the purpose of layout tree
building.
This fixes a crash in box_baseline, due to cells created for
display: table expecting a box child and getting the inline node wrapper
instead.
Fixes#18972.
The Display class already supported all specific values, and now they
will be parsed too. The display property now has a special type
DisplayStyleValue.
Grid and flex containers have their own rules for abspos items, so we
shouldn't try to be clever and put them in the "current" anonymous
wrapper block. That behavior is primarily for the benefit of block &
inline layout.
If the previous sibling of an out-of-flow box has been wrapped in an
anonymous block, we now stuff the out-of-flow box into the anonymous
block as well.
Co-authored-by: Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
Before this patch, we would build full computed style for these pseudo
elements, for every DOM element, even if no ::before/::after selector
actually matched.
This was a colossal waste of time, and we can also just not do that.
Instead, just abort pseudo element style resolution early if no relevant
selectors matched. :^)
The name "initial containing block" was wrong for this, as it doesn't
correspond to the HTML element, and that's specifically what it's
supposed to do! :^)
The shadowRoot property getter that will be added in subsequent commits
has an additional check that checks whether the shadow root is opened.
I didn't update the function logic to match with the IDL interface,
because it's very likely we don't want that check in the existing code,
so that for example closed shadow root elements can still be updated.
Introduce `TableWrapper` type so table wrappers could be
distinguished from block containers and override width
calculation for table wrappers (CSS 2.2 spec, section 17.5.2)
inside BFCs in the way that their width should be equal to
width of table box they wrap.
According to table fixup algorithm:
https://www.w3.org/TR/css-tables-3/#fixup-algorithm
around every table-root should be generated anonymous
box wrapper.
Also this patch implements important part of CSS 2.2
spec that is currently not present in CSS Tables 3
spec draft: https://www.w3.org/TR/CSS22/tables.html#model
that portion of computed properties should be moved
from table-root to table wrapper box. Without having
this part implemented height of absolutely positioned
table with `height: auto` won't be computed correctly.
