* Add initial support for sticky positioning for non-legacy layout
Many tests still fail for a variety of reasons. One of the primary ones
is that CSSOM currently does not return correct values for elements
positioned by sticky nodes. This requires changes to WebRender to work
properly.
* Fix an assertion failure in the legacy layout sticky code
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`.
In the first phase, we gather LineItems and then when we have enough to
form a line we turn them into Fragments. This will make it possible to
more simply implement `vertical-align` and `text-align: justify` because
we need to measure the different aspects of the candidate line and then
produce a Fragments.
This is a general refactor of the way that inline layout works, so comes
with some progressions. In addition there are some new failures.
New failures:
Some tests are now failing because only the test or reference is getting
proper line height when it wasn't before. These should be fixed in a
followup change that properly calculate line-height in more cases:
- /_mozilla/css/list_style_position_a.html
- /css/CSS2/floats/float-no-content-beside-001.html
- /css/css-content/pseudo-element-inline-box.html
- /css/css-flexbox/flexbox_flex-none-wrappable-content.html
Some tests are now failing because floats are now placed properly, but
are no longer in their inline box stacking contexts. These will be fixed
by a followup change which properly parents them:
- /css/filter-effects/filtered-inline-applies-to-float.html.ini
- /css/css-color/inline-opacity-float-child.html.ini
One test is failing due to floating point precision errors:
- /css/CSS2/floats-clear/floats-141.xht.ini
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Clearance was implemented as a Length, where zero meant no clearance.
However, having a clearance of 0px should be different than having
no clearance, since the former can still prevent margin collapse.
This patch keeps the existing behavior, so it won't be possible to get
a clearance of Some(Length::zero()), but it prepares the terrain for
a follow-up to fix calculate_clearance to return the proper thing.
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.
