Fill and stroke properties for containers

13 files changed, 217 insertions, 72 deletions

diff --git a/library/src/layout/container.rs b/library/src/layout/container.rs
index 7814c083..43823339 100644
--- a/library/src/layout/container.rs
+++ b/library/src/layout/container.rs
@@ -60,18 +60,55 @@ pub struct BoxNode {
     pub width: Sizing,
     /// The box's height.
     pub height: Smart<Rel<Length>>,
-    /// The box's baseline shift.
-    pub baseline: Rel<Length>,
 }
 
 #[node]
 impl BoxNode {
+    /// The box's baseline shift.
+    #[property(resolve)]
+    pub const BASELINE: Rel<Length> = Rel::zero();
+
+    /// The box's background color. See the
+    /// [rectangle's documentation]($func/rect.fill) for more details.
+    pub const FILL: Option<Paint> = None;
+
+    /// The box's border color. See the
+    /// [rectangle's documentation]($func/rect.stroke) for more details.
+    #[property(resolve, fold)]
+    pub const STROKE: Sides<Option<Option<PartialStroke>>> = Sides::splat(None);
+
+    /// How much to round the box's corners. See the [rectangle's
+    /// documentation]($func/rect.radius) for more details.
+    #[property(resolve, fold)]
+    pub const RADIUS: Corners<Option<Rel<Length>>> = Corners::splat(Rel::zero());
+
+    /// How much to pad the box's content. See the [rectangle's
+    /// documentation]($func/rect.inset) for more details.
+    #[property(resolve, fold)]
+    pub const INSET: Sides<Option<Rel<Length>>> = Sides::splat(Rel::zero());
+
+    /// How much to expand the box's size without affecting the layout.
+    ///
+    /// This is useful to prevent padding from affecting line layout. For a
+    /// generalized version of the example below, see the documentation for the
+    /// [raw text's block parameter]($func/raw.block).
+    ///
+    /// ```example
+    /// An inline
+    /// #box(
+    ///   fill: luma(235),
+    ///   inset: (x: 3pt, y: 0pt),
+    ///   outset: (y: 3pt),
+    ///   radius: 2pt,
+    /// )[rectangle].
+    #[property(resolve, fold)]
+    pub const OUTSET: Sides<Option<Rel<Length>>> = Sides::splat(Rel::zero());
+
     fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
-        let body = args.eat::<Content>()?.unwrap_or_default();
+        let body = args.eat()?.unwrap_or_default();
         let width = args.named("width")?.unwrap_or_default();
         let height = args.named("height")?.unwrap_or_default();
-        let baseline = args.named("baseline")?.unwrap_or_default();
-        Ok(Self { body, width, height, baseline }.pack())
+        Ok(Self { body, width, height }.pack())
     }
 }
 
@@ -96,42 +133,86 @@ impl Layout for BoxNode {
             .map(|(s, b)| s.map(|v| v.relative_to(b)))
             .unwrap_or(regions.size);
 
+        // Apply inset.
+        let mut child = self.body.clone();
+        let inset = styles.get(Self::INSET);
+        if inset.iter().any(|v| !v.is_zero()) {
+            child = child.clone().padded(inset.map(|side| side.map(Length::from)));
+        }
+
         // Select the appropriate base and expansion for the child depending
         // on whether it is automatically or relatively sized.
         let is_auto = sizing.as_ref().map(Smart::is_auto);
         let expand = regions.expand | !is_auto;
         let pod = Regions::one(size, expand);
-        let mut frame = self.body.layout(vt, styles, pod)?.into_frame();
+        let mut frame = child.layout(vt, styles, pod)?.into_frame();
 
         // Apply baseline shift.
-        let shift = self.baseline.resolve(styles).relative_to(frame.height());
+        let shift = styles.get(Self::BASELINE).relative_to(frame.height());
         if !shift.is_zero() {
             frame.set_baseline(frame.baseline() - shift);
         }
 
+        // Prepare fill and stroke.
+        let fill = styles.get(Self::FILL);
+        let stroke = styles
+            .get(Self::STROKE)
+            .map(|s| s.map(PartialStroke::unwrap_or_default));
+
+        // Add fill and/or stroke.
+        if fill.is_some() || stroke.iter().any(Option::is_some) {
+            let outset = styles.get(Self::OUTSET);
+            let radius = styles.get(Self::RADIUS);
+            frame.fill_and_stroke(fill, stroke, outset, radius);
+        }
+
+        // Apply metadata.
+        frame.meta(styles);
+
         Ok(Fragment::frame(frame))
     }
 }
 
 /// # Block
-/// A block-level container that places content into a separate flow.
+/// A block-level container.
 ///
-/// This can be used to force elements that would otherwise be inline to become
-/// block-level. This is especially useful when writing show rules.
+/// Such a container can be used to separate content, size it and give it a
+/// background or border.
 ///
-/// ## Example
+/// ## Examples
+/// With a block, you can give a background to content while still allowing it
+/// to break across multiple pages. The documentation examples can only have a
+/// single page, but the example below demonstrates how this would work.
 /// ```example
-/// #[
-///   #show heading: it => it.title
-///   = No block
-///   Some text
-/// ]
-///
-/// #[
-///   #show heading: it => block(it.title)
-///   = Block
-///   Some more text
-/// ]
+/// #block(
+///   fill: luma(230),
+///   inset: 8pt,
+///   radius: 4pt,
+///   lorem(30),
+/// )
+/// ```
+///
+/// Blocks are also useful to force elements that would otherwise be inline to
+/// become block-level, especially when writing show rules.
+/// ```example
+/// #show heading: it => it.title
+/// = Blockless
+/// More text.
+///
+/// #show heading: it => block(it.title)
+/// = Blocky
+/// More text.
+/// ```
+///
+/// Last but not least, set rules for the block function can be used to
+/// configure the spacing around arbitrary block-level elements.
+/// ```example
+/// #set align(center)
+/// #show math.formula: set block(above: 8pt, below: 16pt)
+///
+/// This sum of $x$ and $y$:
+/// $ x + y = z $
+/// A second paragraph.
 /// ```
 ///
 /// ## Parameters
@@ -158,16 +239,44 @@ impl Layout for BoxNode {
 #[func]
 #[capable(Layout)]
 #[derive(Debug, Hash)]
-pub struct BlockNode(pub Content);
+pub struct BlockNode {
+    pub body: Content,
+}
 
 #[node]
 impl BlockNode {
+    /// The block's background color. See the
+    /// [rectangle's documentation]($func/rect.fill) for more details.
+    pub const FILL: Option<Paint> = None;
+
+    /// The block's border color. See the
+    /// [rectangle's documentation]($func/rect.stroke) for more details.
+    #[property(resolve, fold)]
+    pub const STROKE: Sides<Option<Option<PartialStroke>>> = Sides::splat(None);
+
+    /// How much to round the block's corners. See the [rectangle's
+    /// documentation]($func/rect.radius) for more details.
+    #[property(resolve, fold)]
+    pub const RADIUS: Corners<Option<Rel<Length>>> = Corners::splat(Rel::zero());
+
+    /// How much to pad the block's content. See the [rectangle's
+    /// documentation]($func/rect.inset) for more details.
+    #[property(resolve, fold)]
+    pub const INSET: Sides<Option<Rel<Length>>> = Sides::splat(Rel::zero());
+
+    /// How much to expand the block's size without affecting the layout. See
+    /// the [rectangle's documentation]($func/rect.outset) for more details.
+    #[property(resolve, fold)]
+    pub const OUTSET: Sides<Option<Rel<Length>>> = Sides::splat(Rel::zero());
+
     /// The spacing between the previous and this block.
     #[property(skip)]
     pub const ABOVE: VNode = VNode::block_spacing(Em::new(1.2).into());
+
     /// The spacing between this and the following block.
     #[property(skip)]
     pub const BELOW: VNode = VNode::block_spacing(Em::new(1.2).into());
+
     /// Whether this block must stick to the following one.
     ///
     /// Use this to prevent page breaks between e.g. a heading and its body.
@@ -175,7 +284,8 @@ impl BlockNode {
     pub const STICKY: bool = false;
 
     fn construct(_: &Vm, args: &mut Args) -> SourceResult<Content> {
-        Ok(Self(args.eat()?.unwrap_or_default()).pack())
+        let body = args.eat()?.unwrap_or_default();
+        Ok(Self { body }.pack())
     }
 
     fn set(...) {
@@ -198,7 +308,37 @@ impl Layout for BlockNode {
         styles: StyleChain,
         regions: Regions,
     ) -> SourceResult<Fragment> {
-        self.0.layout(vt, styles, regions)
+        // Apply inset.
+        let mut child = self.body.clone();
+        let inset = styles.get(Self::INSET);
+        if inset.iter().any(|v| !v.is_zero()) {
+            child = child.clone().padded(inset.map(|side| side.map(Length::from)));
+        }
+
+        // Layout the child.
+        let mut frames = child.layout(vt, styles, regions)?.into_frames();
+
+        // Prepare fill and stroke.
+        let fill = styles.get(Self::FILL);
+        let stroke = styles
+            .get(Self::STROKE)
+            .map(|s| s.map(PartialStroke::unwrap_or_default));
+
+        // Add fill and/or stroke.
+        if fill.is_some() || stroke.iter().any(Option::is_some) {
+            let outset = styles.get(Self::OUTSET);
+            let radius = styles.get(Self::RADIUS);
+            for frame in &mut frames {
+                frame.fill_and_stroke(fill, stroke, outset, radius);
+            }
+        }
+
+        // Apply metadata.
+        for frame in &mut frames {
+            frame.meta(styles);
+        }
+
+        Ok(Fragment::frames(frames))
     }
 }
 
diff --git a/library/src/meta/heading.rs b/library/src/meta/heading.rs
index 8da5cd6e..bc788243 100644
--- a/library/src/meta/heading.rs
+++ b/library/src/meta/heading.rs
@@ -147,7 +147,7 @@ impl Show for HeadingNode {
         if numbers != Value::None {
             realized = numbers.display() + SpaceNode.pack() + realized;
         }
-        Ok(BlockNode(realized).pack())
+        Ok(BlockNode { body: realized }.pack())
     }
 }
 
diff --git a/library/src/meta/outline.rs b/library/src/meta/outline.rs
index da2e1f00..2d1cf185 100644
--- a/library/src/meta/outline.rs
+++ b/library/src/meta/outline.rs
@@ -184,7 +184,6 @@ impl Show for OutlineNode {
                         body: filler.clone(),
                         width: Sizing::Fr(Fr::one()),
                         height: Smart::Auto,
-                        baseline: Rel::zero(),
                     }
                     .pack(),
                 );
diff --git a/library/src/text/raw.rs b/library/src/text/raw.rs
index d29cb7bf..a20ec6f3 100644
--- a/library/src/text/raw.rs
+++ b/library/src/text/raw.rs
@@ -63,17 +63,16 @@ use crate::prelude::*;
 ///   ````example
 ///   // Display inline code in a small box
 ///   // that retains the correct baseline.
-///   #show raw.where(block: false): it => box(rect(
+///   #show raw.where(block: false): box.with(
 ///     fill: luma(240),
 ///     inset: (x: 3pt, y: 0pt),
 ///     outset: (y: 3pt),
 ///     radius: 2pt,
-///     it,
-///   ))
+///   )
 ///
-///   // Display block code in a larger box
+///   // Display block code in a larger block
 ///   // with more padding.
-///   #show raw.where(block: true): rect.with(
+///   #show raw.where(block: true): block.with(
 ///     fill: luma(240),
 ///     inset: 10pt,
 ///     radius: 4pt,
@@ -200,7 +199,7 @@ impl Show for RawNode {
         };
 
         if self.block {
-            realized = BlockNode(realized).pack();
+            realized = BlockNode { body: realized }.pack();
         }
 
         Ok(realized)
diff --git a/library/src/visualize/shape.rs b/library/src/visualize/shape.rs
index 8a256762..7eddc6a6 100644
--- a/library/src/visualize/shape.rs
+++ b/library/src/visualize/shape.rs
@@ -133,28 +133,13 @@ impl RectNode {
     /// current [text edges]($func/text.top-edge).
     ///
     /// ```example
-    /// A #box(rect(inset: 0pt)[tight]) fit.
+    /// #rect(inset: 0pt)[Tight])
     /// ```
     #[property(resolve, fold)]
     pub const INSET: Sides<Option<Rel<Length>>> = Sides::splat(Abs::pt(5.0).into());
 
     /// How much to expand the rectangle's size without affecting the layout.
-    ///
-    /// This is, for instance, useful to prevent an inline rectangle from
-    /// affecting line layout. For a generalized version of the example below,
-    /// see the documentation for the
-    /// [raw text's block parameter]($func/raw.block).
-    ///
-    /// ```example
-    /// This
-    /// #box(rect(
-    ///   fill: luma(235),
-    ///   inset: (x: 3pt, y: 0pt),
-    ///   outset: (y: 3pt),
-    ///   radius: 2pt,
-    /// )[rectangle])
-    /// is inline.
-    /// ```
+    /// See the [box's documentation]($func/box.outset) for more details.
     #[property(resolve, fold)]
     pub const OUTSET: Sides<Option<Rel<Length>>> = Sides::splat(Rel::zero());
 
@@ -535,7 +520,6 @@ fn layout(
     let mut frame;
     if let Some(child) = body {
         let region = resolved.unwrap_or(regions.base());
-
         if kind.is_round() {
             inset = inset.map(|side| side + Ratio::new(0.5 - SQRT_2 / 4.0));
         }
@@ -565,7 +549,7 @@ fn layout(
         frame = Frame::new(size);
     }
 
-    // Add fill and/or stroke.
+    // Prepare stroke.
     let stroke = match stroke {
         Smart::Auto if fill.is_none() => Sides::splat(Some(Stroke::default())),
         Smart::Auto => Sides::splat(None),
@@ -574,21 +558,16 @@ fn layout(
         }
     };
 
-    let outset = outset.relative_to(frame.size());
-    let size = frame.size() + outset.sum_by_axis();
-    let radius = radius.map(|side| side.relative_to(size.x.min(size.y) / 2.0));
-    let pos = Point::new(-outset.left, -outset.top);
-
+    // Add fill and/or stroke.
     if fill.is_some() || stroke.iter().any(Option::is_some) {
         if kind.is_round() {
+            let outset = outset.relative_to(frame.size());
+            let size = frame.size() + outset.sum_by_axis();
+            let pos = Point::new(-outset.left, -outset.top);
             let shape = ellipse(size, fill, stroke.left);
             frame.prepend(pos, Element::Shape(shape));
         } else {
-            frame.prepend_multiple(
-                rounded_rect(size, radius, fill, stroke)
-                    .into_iter()
-                    .map(|x| (pos, Element::Shape(x))),
-            )
+            frame.fill_and_stroke(fill, stroke, outset, radius);
         }
     }
 
diff --git a/src/doc.rs b/src/doc.rs
index 64f7ae91..a15fbca9 100644
--- a/src/doc.rs
+++ b/src/doc.rs
@@ -7,8 +7,8 @@ use std::sync::Arc;
 
 use crate::font::Font;
 use crate::geom::{
-    self, Abs, Align, Axes, Color, Dir, Em, Geometry, Numeric, Paint, Point, RgbaColor,
-    Shape, Size, Stroke, Transform,
+    self, rounded_rect, Abs, Align, Axes, Color, Corners, Dir, Em, Geometry, Numeric,
+    Paint, Point, Rel, RgbaColor, Shape, Sides, Size, Stroke, Transform,
 };
 use crate::image::Image;
 use crate::model::{
@@ -271,6 +271,9 @@ impl Frame {
 
     /// Attach the metadata from this style chain to the frame.
     pub fn meta(&mut self, styles: StyleChain) {
+        if self.is_empty() {
+            return;
+        }
         for meta in styles.get(Meta::DATA) {
             if matches!(meta, Meta::Hidden) {
                 self.clear();
@@ -280,6 +283,25 @@ impl Frame {
         }
     }
 
+    /// Add a fill and stroke with optional radius and outset to the frame.
+    pub fn fill_and_stroke(
+        &mut self,
+        fill: Option<Paint>,
+        stroke: Sides<Option<Stroke>>,
+        outset: Sides<Rel<Abs>>,
+        radius: Corners<Rel<Abs>>,
+    ) {
+        let outset = outset.relative_to(self.size());
+        let size = self.size() + outset.sum_by_axis();
+        let pos = Point::new(-outset.left, -outset.top);
+        let radius = radius.map(|side| side.relative_to(size.x.min(size.y) / 2.0));
+        self.prepend_multiple(
+            rounded_rect(size, radius, fill, stroke)
+                .into_iter()
+                .map(|x| (pos, Element::Shape(x))),
+        )
+    }
+
     /// Arbitrarily transform the contents of the frame.
     pub fn transform(&mut self, transform: Transform) {
         self.group(|g| g.transform = transform);
diff --git a/tests/ref/compiler/show-selector.png b/tests/ref/compiler/show-selector.png
index 799fcf93..bbd303d1 100644
--- a/tests/ref/compiler/show-selector.png
+++ b/tests/ref/compiler/show-selector.png
diff --git a/tests/ref/layout/container-fill.png b/tests/ref/layout/container-fill.png
new file mode 100644
index 00000000..c2cc78d4
--- /dev/null
+++ b/tests/ref/layout/container-fill.png
diff --git a/tests/ref/meta/link.png b/tests/ref/meta/link.png
index 604e09d0..5d175516 100644
--- a/tests/ref/meta/link.png
+++ b/tests/ref/meta/link.png
diff --git a/tests/typ/compiler/show-selector.typ b/tests/typ/compiler/show-selector.typ
index ebd84837..d1229eee 100644
--- a/tests/typ/compiler/show-selector.typ
+++ b/tests/typ/compiler/show-selector.typ
@@ -2,16 +2,15 @@
 
 ---
 // Inline code.
-#show raw.where(block: false): it => box(rect(
+#show raw.where(block: false): box.with(
   radius: 2pt,
-  outset: (y: 3pt),
+  outset: (y: 2.5pt),
   inset: (x: 3pt, y: 0pt),
   fill: luma(230),
-  it,
-))
+)
 
 // Code blocks.
-#show raw.where(block: true): rect.with(
+#show raw.where(block: true): block.with(
   outset: -3pt,
   inset: 11pt,
   fill: luma(230),
diff --git a/tests/typ/compiler/show-text.typ b/tests/typ/compiler/show-text.typ
index e0fdb793..705c1112 100644
--- a/tests/typ/compiler/show-text.typ
+++ b/tests/typ/compiler/show-text.typ
@@ -28,7 +28,7 @@ Treeworld, the World of worlds, is a world.
 ---
 // This is a fun one.
 #set par(justify: true)
-#show regex("\S"): letter => box(rect(inset: 2pt, upper(letter)))
+#show regex("\S"): letter => box(stroke: 1pt, inset: 2pt, upper(letter))
 #lorem(5)
 
 ---
diff --git a/tests/typ/layout/columns.typ b/tests/typ/layout/columns.typ
index 1d82113c..b5dbf96f 100644
--- a/tests/typ/layout/columns.typ
+++ b/tests/typ/layout/columns.typ
@@ -6,10 +6,10 @@
 #set text(lang: "ar", "Noto Sans Arabic", "IBM Plex Serif")
 #set columns(gutter: 30pt)
 
-#box(rect(fill: conifer, height: 8pt, width: 6pt)) وتحفيز
+#box(fill: conifer, height: 8pt, width: 6pt) وتحفيز
 العديد من التفاعلات الكيميائية. (DNA) من أهم الأحماض النووية التي تُشكِّل
 إلى جانب كل من البروتينات والليبيدات والسكريات المتعددة
-#box(rect(fill: eastern, height: 8pt, width: 6pt))
+#box(fill: eastern, height: 8pt, width: 6pt)
 الجزيئات الضخمة الأربعة الضرورية للحياة.
 
 ---
diff --git a/tests/typ/layout/container-fill.typ b/tests/typ/layout/container-fill.typ
new file mode 100644
index 00000000..ab5913ab
--- /dev/null
+++ b/tests/typ/layout/container-fill.typ
@@ -0,0 +1,7 @@
+#set page(height: 100pt)
+#let words = lorem(18).split()
+#block(inset: 8pt, fill: aqua, stroke: aqua.darken(30%))[
+  #words.slice(0, 12).join(" ")
+  #box(fill: teal, outset: 2pt)[incididunt]
+  #words.slice(12).join(" ")
+]