Although DistinctNumeric, which is supposed to abstract the underlying
type, was used to represent CSSPixels, we have a whole bunch of places
in the layout code that assume CSSPixels::value() returns a
floating-point type. This assumption makes it difficult to replace the
underlying type in CSSPixels with a non-floating type.
To make it easier to transition CSSPixels to fixed-point math, one step
we can take is to prevent access to the underlying type using value()
and instead use explicit conversions with the to_float(), to_double(),
and to_int() methods.
Add logic to compute {min, max}-height and use min-height when
calculating table height, per specifications.
Fixes some issues with phylogenetic tree visualizations on Wikipedia.
The specification isn't explicit about it, but the contribution we
compute should be distributed to all columns, not just the first one.
The first reason for it is symmetry, it doesn't make sense for the
increased width of the spanning column to only affect the first column
in the span.
The second reason is the formula for the cell contribution, which is
weighted by the non-spanning width of the cell relative to the total
width of the columns in the same row. This only covers a fraction of the
gap, in order to fully cover it we have to add it to all columns in the
span. For this to be exactly the case when the columns don't all have
the same width, we'd have to add additional weighting based on the width
ratios, but given that the specification doesn't suggest it at all we'll
leave it out for now.
These are only used during layout, and always within formatting context
code, so we might as well put them in FormattingContext and avoid having
to pass the LayoutState around all the time.
Solves conflict in layout tree "type system" when elements <label> (or
<button>) can't have `display: table` because Box can't be
Layout::Label (or Layout::ButtonBox) and Layout::TableBox at the same
time.
This commit implements following missing steps in table layout:
- Calculate final table height
- Resolve percentage height of cells and rows using final table height
- Distribute avilable height to table rows
If total max columns width (grid_max) is zero then available width
should be divided equally between columns. Previously there was
division by zero: `column.max_width / grid_max`.
Previously, the minimum height of a table row was calculated based
on the automatic height of the cells inner layout. This change makes
computed height of a cell boxes also be considered if it has definite
value.
Instead of special-casing FlexFormattingContext in the intrinsic sizing
layout helpers, add FormattingContext::automatic_content_width() and let
each context subclass decide what that means.
No behavior change here, just moving this responsibility.
Change `compute_auto_height_for_block_level_element` to use max height
(`m_automatic_content_height` produced from TFC) for tables with auto
height which is more correct behaviour than treating them like block
containers.
Introduce `table_box()` function that returns table formatting
context root box casted to `TableBox` similar to how it's done
in other formatting contexts like `root()` in BFC and
`flex_container` in FFC. And replace `context_box()` calls
in TFC with calls to `table_box()`.
Fixup rule that table roots need to be wrapped in anonymous
block boxes need to be implemeted instead of having `TableBox`
inherited from `BlockContainer`.
Change column distribution to take in account is_length() and
is_percentage() width values instead of treating all cells like
they have auto width by implementing it in the way described
in CSS Tables 3 spec:
https://www.w3.org/TR/css-tables-3/#width-distribution-algorithm
distribute_width_to_column() is structured to follow schema:
w3.org/TR/css-tables-3/images/CSS-Tables-Column-Width-Assignment.svg
It is not possible to use width of containing block to resolve
cells width because by the time compute_table_measures() is
called row width is not known yet.
Previously when there was no difference between the sum of the
max and min-widths of all columns of a table, it would result in a NaN
value being set as the column's width as there was a division by 0.
This would result in 2+ column tables being reduced to only 1 column.
Fixes the y-position of rows when indicated through the display
attribute `table-row`. Previously there was no y-offset between rows and
so they would overlap.
