Gap values are now represented by Variant<LengthPercentage, NormalGap>.
NormalGap is just an empty struct to represent the `normal` keyword.
This fixes a long-standing issue where we were incorrectly storing gaps
as CSS::Size, which led to us allowing a bunch of invalid gap values.
- Add support for placement of abspos items into track formed by last
line and padding edge of grid container
- Correctly handle auto-positioned abspos items by placing them between
padding edges of grid container
Fixes crashing on https://wpt.live/css/css-grid/abspos/positioned-grid-descendants-001.html
Static position of a box is defined by formatting context type it
belongs to, so let's define this algorithm separately for each FC
instead of assuming FormattingContext::calculate_static_position_rect()
understands how to handle all of them.
Also with this change calculate_static_position_rect() is no longer
virtual function.
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().
Areas are disassembled into boundary lines on `build_grid_areas()` step,
so we can always use them to find grid item's position during placement.
This way we support both ways to define area: `grid-template-areas` and
implicitly using `-start` and `-end` boundary line names.
When placement position is found we always want to do following:
- Mark the occupied cells in the occupation grid
- Add the item to the list of placed items
Therefore, having helper that does both is useful
Moves the code that identifies (start, end, span) for a grid item into
a separate function. By doing so, we can eliminate the duplicated code
between the placement of grid items with definite columns and those
with definite rows.
This change omits some of the comments that reference the spec, as they
were largely irrelevant and unhelpful for making changes or diagnosing
issues.
Before this change, we only considering `grid-auto-flow` to determine
whether a row or column should be added when there was not enough space
in the implicit grid to fit the next unplaced item.
Now, we also choose the direction in which the "auto placement cursor"
is moved, based on the auto flow property.
This change fixes the function that calculates the number of auto-fill
tracks, ensuring it uses height when applied to rows, instead of
assuming that it always operates on columns.
Before this change, parsed grid-template-columns/grid-template-rows
were represented as two lists: line names and track sizes. The problem
with this approach is that it erases the relationship between tracks
and their names, which results in unnecessarily complicated code that
restores this data (incorrectly if repeat() is involved) during layout.
This change solves that by representing line definitions as a list of
sizes and names in the order they were defined.
Visual progression https://genius.com/
Rewrites the grid area building to accurately identify areas that span
multiple rows. Also now we can recognize invalid areas but do not
handle them yet.
Grid items should respect alignment properties if top/right/bottom/left
are not specified.
This change adds a separate implementation of
layout_absolutely_positioned_element that is extended with support for
alignment.
- Ambiguous `raw_value()` method is replaced with `line_number()` and
`span()`.
- `line_name()` that before returned either line name or area name is
replaced with `line_name()` and `area_name()`.
- `Position` type is replaced with `Line` and `Area` type so we don't
have to guess while doing layout.
Affected test expectations:
- `template-lines-and-areas` - improvement over what we had before.
- `named-tracks` - rebaseline a giant test. will have to split it into
smaller tests in the future.
- Out-of-flow items should not affect grid layout
- "The static position of an absolutely-positioned child of a grid
container is determined as if it were the sole grid item in a grid
area whose edges coincide with the content edges of the grid
container."
In c66dbc99ee GFC was updated to use -1
as special value for the infinite growth limit. However, using Optional
instead reduces the risk of accidentally using -1 special value in
layout calculations.
This change implements following paragraph from placement algorithm in
the spec:
"If the largest column span among all the items without a definite
column position is larger than the width of the implicit grid, add
columns to the end of the implicit grid to accommodate that column
span."
There were places in the grid implementation code with copies of this
text, but those were completely unrelated to the code where they were
being pasted so I removed them.
Adds a second pass to resolve percentage paddings and margins of grid
items after track sizes are known. If resolving percentage paddings
or margins affects tracks sizes then second pass to re-resolve track
sizes might also be needed but I cannot come up with an example to
reproduce that so we can leave it to improve in the future :)
This fixes the issue when functions that distribute base_size
or growth_limit to tracks only considered *affected* spanned tracks
while calculating left extra that is available for distribution while
indeed it should be just *all* spanned track by specific item that
extra space size.
This changes grid items position storage type from unsigned to signed
integer so it can represent negative offsets and also updates placement
for grid items with specified column to correctly handle negative
offsets.
Fixes the bug that currently we always consider tracks with percentage
size as ones with "fixed" length even when available size is not
definite. With this change tracks with percentage size when available
size is not definite will be considered as "intrinsic" sized.
Using HashTable of grid positions to represent OccupationGrid allows to
simplify positioning code. For example maybe_add_row() and
maybe_add_column() calls are not needed anymore because there is no
Vector<Vector<bool>> that need to be resized.
No observable changes in grid layout are expected :)
Implements more parts of sizing algorithm for tracks with spanning
items to archive parity with implementation for sizing of tracks
with non-spanning items.
Adds support for grid items with fixed size paddings. Supporting
percentage paddings will probably require to do second pass of tracks
layout: second pass is needed to recalculate tracks sizes when final
items sizes are known when percentage paddings are already resolved.
