There were two kinds of layout tracing controlled by the same debugging
option:
- modern layout: Functionality that dumped a JSON serialization of the
layout tree before and after layout.
- legacy layout: A scope based tracing that reported the process of
layout in a structured way.
I don't think anyone working on layout is using either of these two
features. For modern layout requiring data structure to implement
`serde` serialization is incredibly inconvenient and also generates a
lot of extra code.
We also have a more modern tracing functionality based on perfetto that
we have started to use for layout and IMO it's actually being used and
more robust.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Push the interior mutability into enum variants of `Fragment`, so that
they can be cloned. This saves memory in the `Fragment` tree as the
`Fragment` enum is now a relatively wee 16 bytes and the interior parts
can be a variety of sizes. Before, every `Fragment` was the size of the
biggest kind (`BoxFragment` - 248 bytes).
This a step on the way toward incremental layout.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
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>
This implements the requirements outlined in the [flexbox specification]
about how to position absolute children of flex containers. We must
establish a static position rectangle (to use if all insets are auto)
and also align the child into that rectangle.
[flebox specification]: https://drafts.csswg.org/css-flexbox/#abspos-items
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This makes the names of flow relative geometry consistent with what is
used in the style crate and removes them from a module. With this change
it's more obvious what makes these types different from the ones in
`euclid`.
This is a simple code organization change with no behavior change with
the idea of making Layout 2020 easier to understand by new folks to the
project. The idea is that we will have a cleaner separation between the
different parts of layout ie one directory for the fragment tree and one
(currently multiple) directory for the box tree.
