We previously tried to implement the [table specification algorithm] for
distributing the inline size of cells with `rowspan` > 1. This algorithm
isn't great though, so this change starts switching Servo to using an
algorithm like the one used in LayoutNG from blink. This leads to
improvements in test results.
Limitations:
- Currently, non-fixed layout mode is handled, but a followup change will
very likely addressed fixed mode tables.
- Column merging is not handled at all.
Fixes#6578.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
For example:
```html
<table border="1">
<tr> <td></td> <td></td> </tr>
<tr> <td colspan="2"></td> </tr>
</table>
```
We should initially size the columns according to the cells in the first
row since they have a span of 1. Then we handle the cell in the second
row with a span of 2, this should be able to increase the size of the
columns, but never decrease them.
This change adds a version of row height distribution that follows the
distribtuion algorithm used for tables in Blink's LayoutNG. This is just
an intermediate step toward implementing a distribution algorithm for
both rows and columns more similar to Layout NG.
The CSS Table 3 specification is often wrong with regard to web
compatability, which is why we have abandoned it in favor of the Layout
NG algorithm for row height distribution. this work.
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
This adds support for table rows, columns, rowgroups and colgroups.
There are few additions here:
1. The createion of fragments, which allows script queries and hit
testing to work properly. These fragments are empty as all cells are
still direct descendants of the table fragment.
2. Properly handling size information from tracks and track groups as
well as frustrating rules about reordering rowgroups.
3. Painting a background seemlessly across track groups and groups. This
is a thing that isn't done in legacy layout (nor WebKit)!
Co-authored-by: Oriol Brufau <obrufau@igalia.com>
