Using fixed-point saturated arithmetics for CSSPixels allows to avoid
accumulating floating-point errors.
This implementation is not complete yet: currently saturated
arithmetics implemented only for addition. But it is enough to not
regress any of layout tests we have :)
See https://github.com/SerenityOS/serenity/issues/18566
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 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.
This would previously assert in InlineFormattingContext because we had
an outwardly inline box that wasn't inwardly flow.
Fix this by converting text-based input boxes to inline-blocks. This is
an ad-hoc solution, and there might be a much better way to solve it.
