Now, we will evenly distribute the remaining free space across tracks
using the auto max-tracks sizing function, exactly as the specification
states. Many tests are affected, but they are not visually broken.
Fixes https://github.com/SerenityOS/serenity/issues/22798
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.
The spec says that the sum of affected size + item-incurred increase
should reach the limit, rather than just the item-incurred increase.
This seems to improve layout on the testcase `row-span-2-with-gaps`.
The extra line of space at the bottom of the left div
(`div.grid-item.item-span-two`) is not present anymore, matching other
browsers' layout much more closely.
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.
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
