caisin/typst
1
0
Fork 0
mirror of https://github.com/typst/typst synced 2025-08-13 06:37:57 +08:00
Code Issues Packages Projects Releases Wiki Activity

detect collision between headers/footers and surrounding rows

Browse Source
This commit is contained in:
PgBiel 2025-02-17 17:47:50 -03:00
parent 199bb7c56d
commit 9cfc5706bf
3 changed files with 241 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

143
crates/typst-library/src/layout/grid/resolve.rs
View File

@ -1030,6 +1030,111 @@ impl<'a> CellGrid<'a> {
styles,
);
// Check if the cell's header or footer can expand to the
// cell's position before placing it.
if is_row_group {
// Ensure each cell in a header or footer is fully
// contained within it by expanding the header or footer
// towards this new cell.
let new_child_start = child_start.min(y);
let new_child_end = child_end.max(y + rowspan);
// TODO: Maybe remove this check and just keep the loop,
// we will loop in the "good case" anyway
//
// Quickly detect the case:
// y = 0 => occupied
// y = 1 => empty
// y = 2 => header
// and header tries to expand to y = 0 - invalid, as
// `y = 1` is the earliest row it can occupy.
if new_child_start < first_available_row {
bail!(
cell_span,
"cell would cause header or footer to expand to a non-empty row";
hint: "try moving its cells to later rows"
);
}
// The check above isn't enough, however, even when the
// header is expanding upwards, as it might expand upwards
// towards an occupied row after the first empty row, e.g.
// y = 0 => occupied
// y = 1 => empty (first_available_row = 1)
// y = 2 => occupied
// y = 3 => header
// Here, we should bail if the header tries to expand
// upwards. Note that expanding upwards is only possible
// when row-positioned cells are specified, in one of the
// following cases:
//
// 1. We place e.g. `table.cell(y: 3)` followed by
// `table.cell(y: 2)` (earlier row => upwards);
// 2. We place e.g. `table.cell(y: 3)` followed by
// `[a]` (auto-pos cell favors 'first_available_row', so
// the header tries to expand upwards to place the cell at
// `y = 1`).
//
// Of course, we also need to check for downward expansion
// as there could be a non-empty row below the header, but
// the upward case is highlighted due to its differences.
let new_rows = (new_child_start..child_start.min(new_child_end))
.chain(child_end.max(new_child_start + 1)..new_child_end);
// Note that simply checking for non-empty rows like below
// not only prevents conflicts with top-level cells
// (outside of headers and footers), but also prevents
// conflicts with other headers or footers, since we have
// an invariant that even empty headers and footers must
// contain at least one 'Some(...)' position in
// 'resolved_cells'. More precisely, each header and footer
// has at least one 'Some(...)' cell at 'child_start' and
// at 'child_end - 1' - non-empty headers and footers don't
// span any unnecessary rows.
for new_y in new_rows {
if let Some(new_row @ [_non_empty, ..]) = resolved_cells
.get(new_y * c..)
.map(|cells| &cells[..c.min(cells.len())])
{
if new_row.iter().any(Option::is_some) {
// TODO:
// - Later/earlier rows might be confusing
// (moving to the end always works...)
// - Detect when header or footer collided with
// another header or footer and provide a
// better error message if so.
if new_y < child_start.min(new_child_end) {
bail!(
cell_span,
"cell would cause header or footer to expand to a non-empty row";
hint: "try moving its cells to later rows"
);
} else {
bail!(
cell_span,
"cell would cause header or footer to expand to a non-empty row";
hint: "try moving its cells to earlier rows"
);
}
}
} else {
// Received `None` or an empty slice, so we are
// expanding the header or footer into new rows,
// which is always valid and cannot conflict with
// existing cells. (Note that we only resize
// `resolved_cells` after this check, so, if this
// header or footer is at the bottom of the table
// so far, this loop will end quite early,
// regardless of where this cell was placed or of
// its rowspan value.)
break;
}
}
child_start = new_child_start;
child_end = new_child_end;
}
if largest_index >= resolved_cells.len() {
// Ensure the length of the vector of resolved cells is
// always a multiple of 'c' by pushing full rows every
@ -1098,16 +1203,9 @@ impl<'a> CellGrid<'a> {
*slot = Some(Entry::Merged { parent: resolved_index });
}
}
if is_header || is_footer {
// Ensure each cell in a header or footer is fully
// contained within it.
child_start = child_start.min(y);
child_end = child_end.max(y + rowspan);
}
}
if (is_header || is_footer) && child_start == usize::MAX {
if is_row_group && child_start == usize::MAX {
// Empty header/footer: consider the header/footer to be
// at the next empty row after the latest auto index.
local_auto_index = first_available_row * c;
@ -1118,6 +1216,29 @@ impl<'a> CellGrid<'a> {
// Ensure the automatically chosen row actually exists.
resolved_cells.resize_with(c * (child_start + 1), || None);
}
// Even though this header or footer is fully empty, we add one
// default cell to maintain the invariant that each header and
// footer has at least one `Some(...)` cell at its first row
// and at least one at its last row (here they are the same
// row, of course). This invariant is important to ensure
// `find_next_empty_row` will skip through any existing headers
// and footers without having to loop through them each time.
// Cells themselves, unfortunately, still have to.
assert!(resolved_cells[local_auto_index].is_none());
let (first_x, first_y) = (0, first_available_row);
resolved_cells[local_auto_index] =
Some(Entry::Cell(T::default().resolve_cell(
first_x,
first_y,
&fill.resolve(engine, styles, first_x, first_y)?,
align.resolve(engine, styles, first_x, first_y)?,
inset.resolve(engine, styles, first_x, first_y)?,
stroke.resolve(engine, styles, first_x, first_y)?,
resolve_breakable(first_y, 1),
locator.next(&()),
styles,
)));
}
if is_header {
@ -1782,12 +1903,6 @@ fn resolve_cell_position(
}
// Cell has only chosen its row, not its column.
(Smart::Auto, Smart::Custom(cell_y)) => {
if cell_y < first_available_row {
bail!(
"cell in a header or footer cannot be placed in a row with cells outside that header or footer"
);
}
// Let's find the first column which has that row available.
let first_row_pos = cell_index(0, cell_y)?;
let last_row_pos = first_row_pos

47
tests/suite/layout/grid/footers.typ
View File

@ -417,7 +417,7 @@
table.footer()
)
--- grid-footer-row-pos-cell-inside-conflicts-with-row-outside ---
--- grid-footer-row-pos-cell-inside-conflicts-with-row-before ---
#set page(margin: 2pt)
#set text(6pt)
#table(
@ -427,12 +427,55 @@
table.footer(
table.hline(stroke: red),
table.hline(y: 1, stroke: aqua),
// Error: 5-24 cell in a header or footer cannot be placed in a row with cells outside that header or footer
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to later rows
table.cell(y: 0)[b],
[c]
)
)
--- grid-footer-auto-pos-cell-inside-conflicts-with-row-after ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 2,
inset: 1.5pt,
table.cell(y: 1)[a],
table.footer(
[b], [c],
// TODO: Why is the span just the letter 'd'?
// Error: 6-7 cell would cause header or footer to expand to a non-empty row
// Hint: 6-7 try moving its cells to earlier rows
[d],
),
)
--- grid-footer-row-pos-cell-inside-conflicts-with-row-after ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 2,
inset: 1.5pt,
table.cell(y: 2)[a],
table.footer(
[b], [c],
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to earlier rows
table.cell(y: 3)[d],
),
)
--- grid-footer-conflicts-with-empty-header ---
#table(
columns: 2,
table.header(),
table.footer(
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to later rows
table.cell(y: 0)[a]
),
)
--- issue-5359-column-override-stays-inside-footer ---
#table(
columns: 3,

67
tests/suite/layout/grid/headers.typ
View File

@ -380,6 +380,73 @@
)
)
--- grid-header-row-pos-cell-inside-conflicts-with-row-before ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 3,
inset: 1.5pt,
table.cell(y: 0)[a],
table.header(
table.hline(stroke: red),
table.hline(y: 1, stroke: aqua),
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to later rows
table.cell(y: 0)[b],
[c]
)
)
--- grid-header-row-pos-cell-inside-conflicts-with-row-before-after-first-empty-row ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 3,
inset: 1.5pt,
// Rows: Occupied, Empty, Occupied, Empty, Empty, ...
// Should not be able to expand header from the second Empty to the second Occupied.
table.cell(y: 0)[a],
table.cell(y: 2)[a],
table.header(
table.hline(stroke: red),
table.hline(y: 3, stroke: aqua),
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to later rows
table.cell(y: 2)[b],
)
)
--- grid-header-auto-pos-cell-inside-conflicts-with-row-after ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 2,
inset: 1.5pt,
table.cell(y: 1)[a],
table.header(
[b], [c],
// TODO: A bit odd that this span is just the letter 'd'
// Error: 6-7 cell would cause header or footer to expand to a non-empty row
// Hint: 6-7 try moving its cells to earlier rows
[d],
),
)
--- grid-header-row-pos-cell-inside-conflicts-with-row-after ---
#set page(margin: 2pt)
#set text(6pt)
#table(
columns: 2,
inset: 1.5pt,
table.cell(y: 2)[a],
table.header(
[b], [c],
// Error: 5-24 cell would cause header or footer to expand to a non-empty row
// Hint: 5-24 try moving its cells to earlier rows
table.cell(y: 3)[d],
),
)
--- issue-5359-column-override-stays-inside-header ---
#table(
columns: 3,