mirror of
https://github.com/typst/typst
synced 2025-05-13 20:46:23 +08:00
681 lines
22 KiB
Rust
681 lines
22 KiB
Rust
use crate::prelude::*;
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use crate::text::TextElem;
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use super::Sizing;
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/// Arrange content in a grid.
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///
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/// The grid element allows you to arrange content in a grid. You can define the
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/// number of rows and columns, as well as the size of the gutters between them.
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/// There are multiple sizing modes for columns and rows that can be used to
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/// create complex layouts.
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///
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/// The sizing of the grid is determined by the track sizes specified in the
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/// arguments. Because each of the sizing parameters accepts the same values, we
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/// will explain them just once, here. Each sizing argument accepts an array of
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/// individual track sizes. A track size is either:
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///
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/// - `{auto}`: The track will be sized to fit its contents. It will be at most
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/// as large as the remaining space. If there is more than one `{auto}` track
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/// which, and together they claim more than the available space, the `{auto}`
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/// tracks will fairly distribute the available space among themselves.
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///
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/// - A fixed or relative length (e.g. `{10pt}` or `{20% - 1cm}`): The track
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/// will be exactly of this size.
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///
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/// - A fractional length (e.g. `{1fr}`): Once all other tracks have been sized,
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/// the remaining space will be divided among the fractional tracks according
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/// to their fractions. For example, if there are two fractional tracks, each
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/// with a fraction of `{1fr}`, they will each take up half of the remaining
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/// space.
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///
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/// To specify a single track, the array can be omitted in favor of a single
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/// value. To specify multiple `{auto}` tracks, enter the number of tracks
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/// instead of an array. For example, `columns:` `{3}` is equivalent to
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/// `columns:` `{(auto, auto, auto)}`.
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///
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/// ## Example
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/// ```example
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/// #set text(10pt, style: "italic")
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/// #let cell = rect.with(
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/// inset: 8pt,
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/// fill: rgb("e4e5ea"),
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/// width: 100%,
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/// radius: 6pt
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/// )
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/// #grid(
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/// columns: (60pt, 1fr, 60pt),
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/// rows: (60pt, auto),
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/// gutter: 3pt,
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/// cell(height: 100%)[Easy to learn],
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/// cell(height: 100%)[Great output],
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/// cell(height: 100%)[Intuitive],
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/// cell[Our best Typst yet],
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/// cell[
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/// Responsive design in print
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/// for everyone
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/// ],
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/// cell[One more thing...],
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/// )
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/// ```
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///
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/// Display: Grid
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/// Category: layout
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#[element(Layout)]
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pub struct GridElem {
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/// Defines the column sizes.
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///
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/// Either specify a track size array or provide an integer to create a grid
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/// with that many `{auto}`-sized columns. Note that opposed to rows and
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/// gutters, providing a single track size will only ever create a single
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/// column.
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pub columns: TrackSizings,
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/// Defines the row sizes.
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///
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/// If there are more cells than fit the defined rows, the last row is
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/// repeated until there are no more cells.
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pub rows: TrackSizings,
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/// Defines the gaps between rows & columns.
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///
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/// If there are more gutters than defined sizes, the last gutter is repeated.
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#[external]
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pub gutter: TrackSizings,
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/// Defines the gaps between columns. Takes precedence over `gutter`.
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#[parse(
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let gutter = args.named("gutter")?;
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args.named("column-gutter")?.or_else(|| gutter.clone())
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)]
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pub column_gutter: TrackSizings,
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/// Defines the gaps between rows. Takes precedence over `gutter`.
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#[parse(args.named("row-gutter")?.or_else(|| gutter.clone()))]
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pub row_gutter: TrackSizings,
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/// The contents of the table cells.
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///
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/// The cells are populated in row-major order.
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#[variadic]
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pub children: Vec<Content>,
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}
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impl Layout for GridElem {
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fn layout(
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&self,
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vt: &mut Vt,
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styles: StyleChain,
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regions: Regions,
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) -> SourceResult<Fragment> {
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// Prepare grid layout by unifying content and gutter tracks.
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let cells = self.children();
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let layouter = GridLayouter::new(
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vt,
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Axes::new(&self.columns(styles).0, &self.rows(styles).0),
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Axes::new(&self.column_gutter(styles).0, &self.row_gutter(styles).0),
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&cells,
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regions,
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styles,
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);
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// Measure the columns and layout the grid row-by-row.
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Ok(layouter.layout()?.fragment)
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}
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}
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/// Track sizing definitions.
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#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
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pub struct TrackSizings(pub Vec<Sizing>);
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cast_from_value! {
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TrackSizings,
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sizing: Sizing => Self(vec![sizing]),
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count: NonZeroUsize => Self(vec![Sizing::Auto; count.get()]),
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values: Array => Self(values.into_iter().map(Value::cast).collect::<StrResult<_>>()?),
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}
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cast_to_value! {
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v: TrackSizings => v.0.into()
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}
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/// Performs grid layout.
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pub struct GridLayouter<'a, 'v> {
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/// The core context.
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vt: &'a mut Vt<'v>,
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/// The grid cells.
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cells: &'a [Content],
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/// Whether this is an RTL grid.
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is_rtl: bool,
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/// Whether this grid has gutters.
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has_gutter: bool,
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/// The column tracks including gutter tracks.
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cols: Vec<Sizing>,
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/// The row tracks including gutter tracks.
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rows: Vec<Sizing>,
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/// The regions to layout children into.
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regions: Regions<'a>,
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/// The inherited styles.
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styles: StyleChain<'a>,
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/// Resolved column sizes.
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rcols: Vec<Abs>,
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/// The sum of `rcols`.
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width: Abs,
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/// Resolve row sizes, by region.
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rrows: Vec<Vec<RowPiece>>,
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/// Rows in the current region.
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lrows: Vec<Row>,
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/// The initial size of the current region before we started subtracting.
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initial: Size,
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/// Frames for finished regions.
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finished: Vec<Frame>,
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}
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/// The resulting sizes of columns and rows in a grid.
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#[derive(Debug)]
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pub struct GridLayout {
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/// The fragment.
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pub fragment: Fragment,
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/// The column widths.
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pub cols: Vec<Abs>,
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/// The heights of the resulting rows segments, by region.
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pub rows: Vec<Vec<RowPiece>>,
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}
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/// Details about a resulting row piece.
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#[derive(Debug)]
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pub struct RowPiece {
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/// The height of the segment.
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pub height: Abs,
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/// The index of the row.
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pub y: usize,
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}
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/// Produced by initial row layout, auto and relative rows are already finished,
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/// fractional rows not yet.
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enum Row {
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/// Finished row frame of auto or relative row with y index.
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Frame(Frame, usize),
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/// Fractional row with y index.
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Fr(Fr, usize),
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}
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impl<'a, 'v> GridLayouter<'a, 'v> {
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/// Create a new grid layouter.
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///
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/// This prepares grid layout by unifying content and gutter tracks.
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pub fn new(
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vt: &'a mut Vt<'v>,
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tracks: Axes<&[Sizing]>,
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gutter: Axes<&[Sizing]>,
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cells: &'a [Content],
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regions: Regions<'a>,
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styles: StyleChain<'a>,
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) -> Self {
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let mut cols = vec![];
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let mut rows = vec![];
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// Number of content columns: Always at least one.
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let c = tracks.x.len().max(1);
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// Number of content rows: At least as many as given, but also at least
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// as many as needed to place each item.
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let r = {
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let len = cells.len();
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let given = tracks.y.len();
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let needed = len / c + (len % c).clamp(0, 1);
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given.max(needed)
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};
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let has_gutter = gutter.any(|tracks| !tracks.is_empty());
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let auto = Sizing::Auto;
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let zero = Sizing::Rel(Rel::zero());
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let get_or = |tracks: &[_], idx, default| {
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tracks.get(idx).or(tracks.last()).copied().unwrap_or(default)
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};
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// Collect content and gutter columns.
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for x in 0..c {
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cols.push(get_or(tracks.x, x, auto));
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if has_gutter {
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cols.push(get_or(gutter.x, x, zero));
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}
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}
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// Collect content and gutter rows.
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for y in 0..r {
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rows.push(get_or(tracks.y, y, auto));
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if has_gutter {
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rows.push(get_or(gutter.y, y, zero));
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}
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}
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// Remove superfluous gutter tracks.
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if has_gutter {
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cols.pop();
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rows.pop();
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}
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// Reverse for RTL.
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let is_rtl = TextElem::dir_in(styles) == Dir::RTL;
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if is_rtl {
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cols.reverse();
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}
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let rcols = vec![Abs::zero(); cols.len()];
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let lrows = vec![];
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// We use these regions for auto row measurement. Since at that moment,
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// columns are already sized, we can enable horizontal expansion.
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let mut regions = regions.clone();
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regions.expand = Axes::new(true, false);
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Self {
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vt,
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cells,
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is_rtl,
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has_gutter,
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cols,
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rows,
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regions,
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styles,
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rcols,
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width: Abs::zero(),
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rrows: vec![],
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lrows,
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initial: regions.size,
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finished: vec![],
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}
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}
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/// Determines the columns sizes and then layouts the grid row-by-row.
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pub fn layout(mut self) -> SourceResult<GridLayout> {
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self.measure_columns()?;
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for y in 0..self.rows.len() {
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// Skip to next region if current one is full, but only for content
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// rows, not for gutter rows.
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if y % 2 == 0 && self.regions.is_full() {
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self.finish_region()?;
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}
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match self.rows[y] {
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Sizing::Auto => self.layout_auto_row(y)?,
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Sizing::Rel(v) => self.layout_relative_row(v, y)?,
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Sizing::Fr(v) => self.lrows.push(Row::Fr(v, y)),
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}
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}
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self.finish_region()?;
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Ok(GridLayout {
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fragment: Fragment::frames(self.finished),
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cols: self.rcols,
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rows: self.rrows,
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})
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}
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/// Determine all column sizes.
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fn measure_columns(&mut self) -> SourceResult<()> {
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// Sum of sizes of resolved relative tracks.
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let mut rel = Abs::zero();
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// Sum of fractions of all fractional tracks.
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let mut fr = Fr::zero();
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// Resolve the size of all relative columns and compute the sum of all
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// fractional tracks.
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for (&col, rcol) in self.cols.iter().zip(&mut self.rcols) {
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match col {
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Sizing::Auto => {}
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Sizing::Rel(v) => {
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let resolved =
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v.resolve(self.styles).relative_to(self.regions.base().x);
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*rcol = resolved;
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rel += resolved;
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}
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Sizing::Fr(v) => fr += v,
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}
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}
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// Size that is not used by fixed-size columns.
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let available = self.regions.size.x - rel;
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if available >= Abs::zero() {
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// Determine size of auto columns.
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let (auto, count) = self.measure_auto_columns(available)?;
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// If there is remaining space, distribute it to fractional columns,
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// otherwise shrink auto columns.
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let remaining = available - auto;
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if remaining >= Abs::zero() {
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self.grow_fractional_columns(remaining, fr);
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} else {
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self.shrink_auto_columns(available, count);
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}
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}
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// Sum up the resolved column sizes once here.
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self.width = self.rcols.iter().sum();
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Ok(())
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}
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/// Measure the size that is available to auto columns.
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fn measure_auto_columns(&mut self, available: Abs) -> SourceResult<(Abs, usize)> {
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let mut auto = Abs::zero();
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let mut count = 0;
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// Determine size of auto columns by laying out all cells in those
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// columns, measuring them and finding the largest one.
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for (x, &col) in self.cols.iter().enumerate() {
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if col != Sizing::Auto {
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continue;
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}
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let mut resolved = Abs::zero();
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for y in 0..self.rows.len() {
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if let Some(cell) = self.cell(x, y) {
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// For relative rows, we can already resolve the correct
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// base and for auto and fr we could only guess anyway.
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let height = match self.rows[y] {
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Sizing::Rel(v) => {
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v.resolve(self.styles).relative_to(self.regions.base().y)
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}
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_ => self.regions.base().y,
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};
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let size = Size::new(available, height);
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let pod = Regions::one(size, Axes::splat(false));
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let frame = cell.measure(self.vt, self.styles, pod)?.into_frame();
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resolved.set_max(frame.width());
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}
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}
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self.rcols[x] = resolved;
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auto += resolved;
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count += 1;
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}
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Ok((auto, count))
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}
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/// Distribute remaining space to fractional columns.
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fn grow_fractional_columns(&mut self, remaining: Abs, fr: Fr) {
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if fr.is_zero() {
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return;
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}
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for (&col, rcol) in self.cols.iter().zip(&mut self.rcols) {
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if let Sizing::Fr(v) = col {
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*rcol = v.share(fr, remaining);
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}
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}
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}
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/// Redistribute space to auto columns so that each gets a fair share.
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fn shrink_auto_columns(&mut self, available: Abs, count: usize) {
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let mut last;
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let mut fair = -Abs::inf();
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let mut redistribute = available;
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let mut overlarge = count;
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let mut changed = true;
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// Iteratively remove columns that don't need to be shrunk.
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while changed && overlarge > 0 {
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changed = false;
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last = fair;
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fair = redistribute / (overlarge as f64);
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for (&col, &rcol) in self.cols.iter().zip(&self.rcols) {
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// Remove an auto column if it is not overlarge (rcol <= fair),
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// but also hasn't already been removed (rcol > last).
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if col == Sizing::Auto && rcol <= fair && rcol > last {
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redistribute -= rcol;
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overlarge -= 1;
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changed = true;
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}
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}
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}
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// Redistribute space fairly among overlarge columns.
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for (&col, rcol) in self.cols.iter().zip(&mut self.rcols) {
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if col == Sizing::Auto && *rcol > fair {
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*rcol = fair;
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}
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}
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}
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/// Layout a row with automatic height. Such a row may break across multiple
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/// regions.
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fn layout_auto_row(&mut self, y: usize) -> SourceResult<()> {
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let mut resolved: Vec<Abs> = vec![];
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let mut skip = false;
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// Determine the size for each region of the row.
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for (x, &rcol) in self.rcols.iter().enumerate() {
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if let Some(cell) = self.cell(x, y) {
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let mut pod = self.regions;
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pod.size.x = rcol;
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let frames = cell.measure(self.vt, self.styles, pod)?.into_frames();
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if let [first, rest @ ..] = frames.as_slice() {
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skip |=
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first.is_empty() && rest.iter().any(|frame| !frame.is_empty());
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}
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// For each region, we want to know the maximum height any
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// column requires.
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let mut sizes = frames.iter().map(|frame| frame.height());
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for (target, size) in resolved.iter_mut().zip(&mut sizes) {
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target.set_max(size);
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}
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// New heights are maximal by virtue of being new. Note that
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// this extend only uses the rest of the sizes iterator.
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resolved.extend(sizes);
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}
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}
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// Nothing to layout.
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if resolved.is_empty() {
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return Ok(());
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}
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// Layout into a single region.
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if let &[first] = resolved.as_slice() {
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let frame = self.layout_single_row(first, y)?;
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self.push_row(frame, y);
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return Ok(());
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}
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// Skip the first region if it's empty for some cell.
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if skip && !self.regions.in_last() {
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self.finish_region()?;
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resolved.remove(0);
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}
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// Expand all but the last region.
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// Skip the first region if the space is eaten up by an fr row.
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let len = resolved.len();
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for (region, target) in self
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.regions
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.iter()
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.zip(&mut resolved[..len - 1])
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.skip(self.lrows.iter().any(|row| matches!(row, Row::Fr(..))) as usize)
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{
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target.set_max(region.y);
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}
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// Layout into multiple regions.
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let fragment = self.layout_multi_row(&resolved, y)?;
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let len = fragment.len();
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for (i, frame) in fragment.into_iter().enumerate() {
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self.push_row(frame, y);
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if i + 1 < len {
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self.finish_region()?;
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}
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}
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Ok(())
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}
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/// Layout a row with relative height. Such a row cannot break across
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/// multiple regions, but it may force a region break.
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fn layout_relative_row(&mut self, v: Rel<Length>, y: usize) -> SourceResult<()> {
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let resolved = v.resolve(self.styles).relative_to(self.regions.base().y);
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let frame = self.layout_single_row(resolved, y)?;
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// Skip to fitting region.
|
|
let height = frame.height();
|
|
while !self.regions.size.y.fits(height) && !self.regions.in_last() {
|
|
self.finish_region()?;
|
|
|
|
// Don't skip multiple regions for gutter and don't push a row.
|
|
if y % 2 == 1 {
|
|
return Ok(());
|
|
}
|
|
}
|
|
|
|
self.push_row(frame, y);
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Layout a row with fixed height and return its frame.
|
|
fn layout_single_row(&mut self, height: Abs, y: usize) -> SourceResult<Frame> {
|
|
let mut output = Frame::new(Size::new(self.width, height));
|
|
let mut pos = Point::zero();
|
|
|
|
for (x, &rcol) in self.rcols.iter().enumerate() {
|
|
if let Some(cell) = self.cell(x, y) {
|
|
let size = Size::new(rcol, height);
|
|
let mut pod = Regions::one(size, Axes::splat(true));
|
|
if self.rows[y] == Sizing::Auto {
|
|
pod.full = self.regions.full;
|
|
}
|
|
let frame = cell.layout(self.vt, self.styles, pod)?.into_frame();
|
|
output.push_frame(pos, frame);
|
|
}
|
|
|
|
pos.x += rcol;
|
|
}
|
|
|
|
Ok(output)
|
|
}
|
|
|
|
/// Layout a row spanning multiple regions.
|
|
fn layout_multi_row(&mut self, heights: &[Abs], y: usize) -> SourceResult<Fragment> {
|
|
// Prepare frames.
|
|
let mut outputs: Vec<_> = heights
|
|
.iter()
|
|
.map(|&h| Frame::new(Size::new(self.width, h)))
|
|
.collect();
|
|
|
|
// Prepare regions.
|
|
let size = Size::new(self.width, heights[0]);
|
|
let mut pod = Regions::one(size, Axes::splat(true));
|
|
pod.full = self.regions.full;
|
|
pod.backlog = &heights[1..];
|
|
|
|
// Layout the row.
|
|
let mut pos = Point::zero();
|
|
for (x, &rcol) in self.rcols.iter().enumerate() {
|
|
if let Some(cell) = self.cell(x, y) {
|
|
pod.size.x = rcol;
|
|
|
|
// Push the layouted frames into the individual output frames.
|
|
let fragment = cell.layout(self.vt, self.styles, pod)?;
|
|
for (output, frame) in outputs.iter_mut().zip(fragment) {
|
|
output.push_frame(pos, frame);
|
|
}
|
|
}
|
|
|
|
pos.x += rcol;
|
|
}
|
|
|
|
Ok(Fragment::frames(outputs))
|
|
}
|
|
|
|
/// Push a row frame into the current region.
|
|
fn push_row(&mut self, frame: Frame, y: usize) {
|
|
self.regions.size.y -= frame.height();
|
|
self.lrows.push(Row::Frame(frame, y));
|
|
}
|
|
|
|
/// Finish rows for one region.
|
|
fn finish_region(&mut self) -> SourceResult<()> {
|
|
// Determine the height of existing rows in the region.
|
|
let mut used = Abs::zero();
|
|
let mut fr = Fr::zero();
|
|
for row in &self.lrows {
|
|
match row {
|
|
Row::Frame(frame, _) => used += frame.height(),
|
|
Row::Fr(v, _) => fr += *v,
|
|
}
|
|
}
|
|
|
|
// Determine the size of the grid in this region, expanding fully if
|
|
// there are fr rows.
|
|
let mut size = Size::new(self.width, used).min(self.initial);
|
|
if fr.get() > 0.0 && self.initial.y.is_finite() {
|
|
size.y = self.initial.y;
|
|
}
|
|
|
|
// The frame for the region.
|
|
let mut output = Frame::new(size);
|
|
let mut pos = Point::zero();
|
|
let mut rrows = vec![];
|
|
|
|
// Place finished rows and layout fractional rows.
|
|
for row in std::mem::take(&mut self.lrows) {
|
|
let (frame, y) = match row {
|
|
Row::Frame(frame, y) => (frame, y),
|
|
Row::Fr(v, y) => {
|
|
let remaining = self.regions.full - used;
|
|
let height = v.share(fr, remaining);
|
|
(self.layout_single_row(height, y)?, y)
|
|
}
|
|
};
|
|
|
|
let height = frame.height();
|
|
output.push_frame(pos, frame);
|
|
rrows.push(RowPiece { height, y });
|
|
pos.y += height;
|
|
}
|
|
|
|
self.finished.push(output);
|
|
self.rrows.push(rrows);
|
|
self.regions.next();
|
|
self.initial = self.regions.size;
|
|
|
|
Ok(())
|
|
}
|
|
|
|
/// Get the content of the cell in column `x` and row `y`.
|
|
///
|
|
/// Returns `None` if it's a gutter cell.
|
|
#[track_caller]
|
|
fn cell(&self, mut x: usize, y: usize) -> Option<&'a Content> {
|
|
assert!(x < self.cols.len());
|
|
assert!(y < self.rows.len());
|
|
|
|
// Columns are reorded, but the cell slice is not.
|
|
if self.is_rtl {
|
|
x = self.cols.len() - 1 - x;
|
|
}
|
|
|
|
if self.has_gutter {
|
|
// Even columns and rows are children, odd ones are gutter.
|
|
if x % 2 == 0 && y % 2 == 0 {
|
|
let c = 1 + self.cols.len() / 2;
|
|
self.cells.get((y / 2) * c + x / 2)
|
|
} else {
|
|
None
|
|
}
|
|
} else {
|
|
let c = self.cols.len();
|
|
self.cells.get(y * c + x)
|
|
}
|
|
}
|
|
}
|