This change removes the `effective_writing_mode` concept and tries to
properly implement right-to-left layout support for all non-inline
writing modes. In general, what needs to happen is that rectangles
need to be converted to physical rectangles using the containing block.
A right-to-left rectangle's inline start is on the right physical side
of the containing block. Likewise a positive inline offset in
right-to-left text is a negative physical one.
The implementation here is pretty good for most layout modes, but floats
are still a bit in process. Currently, floats are processed in the
logical layout of the block container, but there still might be issues
with float interaction with mixed RTL and LTR.
While this does move us closer to supporting vertical writing modes,
this is still unsupported.
New failures:
- Vertical writing mode not supported:
- `/css/CSS2/floats/floats-placement-vertical-001b.xht`
- `/css/CSS2/floats/floats-placement-vertical-001c.xht`
- Absolutes inlines should avoid floats (#33323)
- `/css/css-position/position-absolute-dynamic-static-position-floats-004.html`
- No support for grid
- `/css/css-align/self-alignment/self-align-safe-unsafe-grid-003.html`
- `/css/css-position/static-position/inline-level-absolute-in-block-level-context-009.html`
- `/css/css-position/static-position/inline-level-absolute-in-block-level-context-010.html`
- Cannot reproduce these locally on any platform. Very mysterious:
- `/css/css-tables/row-group-margin-border-padding.html`
- `/css/css-tables/row-margin-border-padding.html`
- Exposes bugs we have related to hanging whitespace in preserved
whitespace inlines:
- `/css/css-text/white-space/trailing-space-and-text-alignment-rtl-003.html`
- `/css/css-text/white-space/white-space-pre-wrap-trailing-spaces-023.html`
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Rakhi Sharma <atbrakhi@igalia.com>
* feat: Support font-relative `ch` and `ic` units
After #31966, which made it possible for the first time to resolve
font-relative CSS units, this change adds support for the `ch` and
`ic` units.
One difference with the `ex` unit that was added in that PR is that
these units must reflect the advance width of a character (the zero
digit in the case of `ch`, and the CJK water radical for `ic`) as it
would be rendered by the current font group. This means that the size
of these units don't only depend on the first available font, in the
case where that font does not contain a glyph for that character.
This is implemented by adding the advance width for these two
characters as optional fields of `FontMetrics`, so the advance width
computation happens in advance. Then, when the font metrics are
queried as part of unit resolution, the font group is searched for the
first font containing that character.
This change only implements support for these units in upright
typesetting modes, since Servo does not yet have support for vertical
writing modes. This means that many of the WPT tests that test for the
behavior of these units with vertical writing modes do not pass.
This change also makes a number of WPT tests pass, which relied on the
`ch` and `ic` units. It, however, also makes the test
`/css/css-text/white-space/text-wrap-balance-overflow-002.html` fail,
since it tests `text-wrap: balance`, which Servo does not yet
implement, and it was only previously passing by chance due to the
previous behavior of these units.
* Revert Python 3.10-related changes to wss
* Fix formatting
* Remove test expectation
