Inline nodes in our layout tree have a position, so let's show it. By
centralizing the logic for this, block nodes now lose their redundant
'content-size' dump info which is already part of the box model dump.
We were always creating an anonymous container for the inline contents
of table cells, but the layout node we spawn for the table cells
themselves already is capable of dealing with inline nodes. Regular
logic should kick in for dealing with the block/inline node invariant.
Browsers such as Chrome and Firefox apply an arbitrary scale to the
current font size if `normal` is used for `line-height`. Firefox uses
1.2 while Chrome uses 1.15. Let's go with the latter for now, it's
relatively easy to change if we ever want to go back on that decision.
This also requires updating the expectations for a lot of layout tests.
The upside of this is that it's a bit easier to compare our layout
results to other browsers', especially Chrome.
This fixes an issue where CSS vertical-align on a table-cell box would
incorrectly apply to both the table-cell box and any inline content it
had inside.
- Include vertical border spacing in row group offset calculation so
that they are axis-aligned with child row/cell elements. This makes it
so there isn't horizontal and vertical overflow caused by child
row/cell elements.
- Include horizontal border spacing in tr width calculations. This makes
it so tr elements don't have overflow anymore when there are multiple
columns.
- Apply vertical caption offset to row group top offset.
- Don't double-count top padding when calculating vertical offset for
tr and row groups.
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.
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.
This patch just adds the new root paintable and updates the tests
expectations. The next patch will move painting logic from the layout
viewport to the paint viewport.
Instead of just measuring the layout viewport, we now measure overflow
in every box that is a scroll container.
This has the side effect of no longer creating paintables for layout
boxes that didn't participate in layout. (For example, empty/anonymous
boxes that were ignored by flex itemization.)
Such boxes are now marked as "(not painted)" in the layout tree dumps,
as they have no paintable to dump geometry from.
Since there are no table-specific boxes anymore it would be nice to
output their types additionally in layout dump so we can tell table
boxes from "regular" boxes.
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.
