Use this cached pointer to the containing block's used values when
obviously possible. This avoids a hash lookup each time, and these
hash lookups do show up in profiles.
Before this change, a formatting context was responsible for layout of
absolutely positioned boxes whose FC root box was their parent (either
directly or indirectly). This only worked correctly when the containing
block of the absolutely positioned child did not escape the FC root.
This is because the width and height of an absolutely positioned box are
resolved based on the size of its containing block, so we needed to
ensure that the containing block's layout was completed before laying
out an absolutely positioned box.
With this change, the layout of absolutely positioned boxes is delayed
until the FC responsible for the containing block's layout is complete.
This has affected the way we calculate the static position. It is no
longer possible to ask the FC for a box's static position, as this FC's
state might be gone by the time the layout for absolutely positioned
elements occurs. Instead, the "static position rectangle" (a concept
from the spec) is saved in the layout state, along with information on
how to align the box within this rectangle when its width and height are
resolved.
FormattingContext::run() does not allow reentrancy, so it's safe to
save and access layout mode from FC object. This avoids need to drill it
through methods of a formatting context and makes it clear that this
value could never be changed after FC construction.
Root formatting context box is passed into constructor and saved in FC,
so it's possible to access it from there instead of passing the same
box into run().
When traversing the layout tree to find an appropriate box child to
derive the baseline from. Only the child's margin and offset was being
applied. Now we sum each offset on the recursive call.
When both insets in a given axis are auto, we should use the static
position for absolutely positioned elements.
By doing this correctly, we exposed a bunch of other small bugs which
had to be fixed to compensate for new test failures. Those fixes are
included here as well:
- Don't apply margins twice.
- Compute the static position containing block chain correctly.
This makes https://brave.com/ look much better. :^)
There is no need to run full table layout if we are only interested in
calculating its width.
This change reduces compute_table_box_width_inside_table_wrapper()
from ~30% to ~15% in profiles of "File changed" pages on github.
Table wrappers don't quite behave the same as most elements, in that
their computed height and width are not meant to be used for layout.
Instead, we now calculate suitable widths and heights based on the
contents of the table wrapper when performing absolute layout.
Fixes the layout of
http://wpt.live/css/css-position/position-absolute-center-007.html
In particular, these two interesting cases:
- The containing block of an abspos box is always definite from the
perspective of the abspos box.
- When resolving abspos box sizes from two opposing fixed insets,
we now mark those sizes as definite (since no layout was required
to resolve them).
With this change "max-width: max-content" is treated as "none" when
the available width is also "max-content". This fix prevents a stack
overflow in the grid track size maximization algorithm by avoiding
recursive calls to calculate_max_width() when determining the maximum
grid container size.
Similar to calculate_inner_width(), let's make the caller responsible
for handling "auto" instead of returning the input height as is when
when it cannot be resolved.
Initially, this function was made to return CSS::Length because some of
its callers were expecting it to ignore "auto" width on input and
return it as is. Instead, let's just forbid using "auto" for input
width and always return CSSPixels.
According to the CSS font matching algorithm specification, it is
supposed to be executed for each glyph instead of each text run, as is
currently done. This change partially implements this by having the
font matching algorithm produce a list of fonts against which each
glyph will be tested to find its suitable font.
Now, it becomes possible to have per-glyph fallback fonts: if the
needed glyph is not present in a font, we can check the subsequent
fonts in the list.
When a box does not have a top, left, bottom, or right, there is no
need to adjust the offset for positioning relative to the padding edge,
because the box remains in the normal flow.
By using available_inner_space_or_constraints_from(available_space), we
ensure that the available space used to calculate the min/max content
height is constrained by the width specified for the box itself
(I know that at least GFC always expects available width to be
constrained by specified width if there is any).
This change improves layout in "Recent news" block on
https://telegram.org/
The postitioning enum values are used by the position CSS property.
Unfortunately, the prior naming clashes with the CSS Values-4 type
named position, which will be implemented in a later commit.
The existing implementation has some pre-existing issues where it is
incorrectly assumes that byte offsets are given through the IDL instead
of UTF-16 code units. While making these changes, leave some FIXMEs for
that.
The value is originally set using a `CSSPixels` value converted to
double, then when it is used it is always converted back to a
`CSSPixels` again. Let's just store it as that instead.
Some replaced elements can have intrinsic aspect ratios but no
intrinsic size. In these cases, the tentative sizes are undefined, and
can therefore sometimes be zero. However, when resolving the size
constraints, we are already guaranteed to have an intrinsic aspect
ratio, so let's use that instead to calculate the resolved sizes.
Previously, we would run through all the constraints in the spec one by
one, but if we check and resolve each constraint in the order they are
defined in the spec, only the first four will ever match.
This leads me to believe that these constraints are meant to be
mutually exclusive instead, meaning that we must check the most
specific constraints first and return upon the first resolution that
matches.
This allows us to retain perfect precision for aspect ratios derived
from either the intrinsic sizes of replaced elements, or the
`aspect-ratio` CSS property.
There's a particularly awkward case where the static position of an
abspos child of a flex container is dependent on its height. This can
happen when `align-items: center` is in effect, as we have to adjust
the abspos child's Y position by half of its height.
This patch solves the issue by reordering operations in the abspos
height resolution algorithm, to make sure that height is resolved
before the static position is calculated.
Since we always pass the px value as an argument to resolved(), we can
pass it directly as CSSPixels instead of wrapping it in Length. This
approach allows us to avoid converting to a double, resulting in fewer
precision issues.
This is intended to annotate conversions from unknown floating-point
values to CSSPixels, and make it more obvious the fp value will be
rounded to the nearest fixed-point value.
In general it is not safe to convert any arbitrary floating-point value
to CSSPixels. CSSPixels has a resolution of 0.015625, which for small
values (e.g. scale factors between 0 and 1), can produce bad results
if converted to CSSPixels then scaled back up. In the worst case values
can underflow to zero and produce incorrect results.
And treat them as "auto" for now, per CSS-SIZING-3, with a FIXME about
supporting more layout directions.
This fixes an issue on MDN where `height: max-content` was not
overriding height from non-CSS presentational hints.
When a box is sized under max-content constraint, any percentage value
set for max-width should be considered as if it were infinite. In other
words, it should have no effect on restricting the box's width.
There's no reason for this API to require a Layout::Box as input.
Any node that can have layout state is welcome, so this patch makes it
take NodeWithStyleAndBoxModelMetrics.
Changing `calculate_min_content_heigh()` and
`calculate_min_content_heigh()` to accept width as `CSSPixels`, instead
of `AvailableSize` that might be indefinite, makes it more explicit
that width is supposed to be known by the time height is measured.
This change has a bit of collateral damage which is rows height
calculation regression in `table/inline-table-width` that worked before
by accident.
Change associativity in computing of replaced element size to improve
precision of division.
Fixes vertically squashed image from Mozilla splash page MDN example.
