1 files changed, 79 insertions, 0 deletions
diff --git a/crates/typst-library/src/layout/repeat.rs b/crates/typst-library/src/layout/repeat.rs
new file mode 100644
index 00000000..646eb991
--- /dev/null
+++ b/crates/typst-library/src/layout/repeat.rs
@@ -0,0 +1,79 @@
+use crate::prelude::*;
+
+use super::AlignElem;
+
+/// Repeats content to the available space.
+///
+/// This can be useful when implementing a custom index, reference, or outline.
+///
+/// Space may be inserted between the instances of the body parameter, so be
+/// sure to include negative space if you need the instances to overlap.
+///
+/// Errors if there no bounds on the available space, as it would create
+/// infinite content.
+///
+/// ## Example { #example }
+/// ```example
+/// Sign on the dotted line:
+/// #box(width: 1fr, repeat[.])
+///
+/// #set text(10pt)
+/// #v(8pt, weak: true)
+/// #align(right)[
+///   Berlin, the 22nd of December, 2022
+/// ]
+/// ```
+///
+/// Display: Repeat
+/// Category: layout
+#[element(Layout)]
+pub struct RepeatElem {
+    /// The content to repeat.
+    #[required]
+    pub body: Content,
+}
+
+impl Layout for RepeatElem {
+    #[tracing::instrument(name = "RepeatElem::layout", skip_all)]
+    fn layout(
+        &self,
+        vt: &mut Vt,
+        styles: StyleChain,
+        regions: Regions,
+    ) -> SourceResult<Fragment> {
+        let pod = Regions::one(regions.size, Axes::new(false, false));
+        let piece = self.body().layout(vt, styles, pod)?.into_frame();
+        let align = AlignElem::alignment_in(styles).x.resolve(styles);
+
+        let fill = regions.size.x;
+        let width = piece.width();
+        let count = (fill / width).floor();
+        let remaining = fill % width;
+        let apart = remaining / (count - 1.0);
+
+        let size = Size::new(regions.size.x, piece.height());
+
+        if !size.is_finite() {
+            bail!(self.span(), "repeat with no size restrictions");
+        }
+
+        let mut frame = Frame::new(size);
+        if piece.has_baseline() {
+            frame.set_baseline(piece.baseline());
+        }
+
+        let mut offset = Abs::zero();
+        if count == 1.0 {
+            offset += align.position(remaining);
+        }
+
+        if width > Abs::zero() {
+            for _ in 0..(count as usize).min(1000) {
+                frame.push_frame(Point::with_x(offset), piece.clone());
+                offset += piece.width() + apart;
+            }
+        }
+
+        Ok(Fragment::frame(frame))
+    }
+}