Reorganize library

1 files changed, 71 insertions, 0 deletions

diff --git a/src/library/layout/align.rs b/src/library/layout/align.rs
new file mode 100644
index 00000000..7fbe0d01
--- /dev/null
+++ b/src/library/layout/align.rs
@@ -0,0 +1,71 @@
+use crate::library::prelude::*;
+use crate::library::text::ParNode;
+
+/// Align a node along the layouting axes.
+#[derive(Debug, Hash)]
+pub struct AlignNode {
+    /// How to align the node horizontally and vertically.
+    pub aligns: Spec<Option<Align>>,
+    /// The node to be aligned.
+    pub child: LayoutNode,
+}
+
+#[class]
+impl AlignNode {
+    fn construct(_: &mut Context, args: &mut Args) -> TypResult<Template> {
+        let aligns: Spec<_> = args.find()?.unwrap_or_default();
+        let body: LayoutNode = args.expect("body")?;
+        Ok(Template::block(body.aligned(aligns)))
+    }
+}
+
+impl Layout for AlignNode {
+    fn layout(
+        &self,
+        ctx: &mut Context,
+        regions: &Regions,
+        styles: StyleChain,
+    ) -> TypResult<Vec<Arc<Frame>>> {
+        // The child only needs to expand along an axis if there's no alignment.
+        let mut pod = regions.clone();
+        pod.expand &= self.aligns.map_is_none();
+
+        // Align paragraphs inside the child.
+        let mut passed = StyleMap::new();
+        if let Some(align) = self.aligns.x {
+            passed.set(ParNode::ALIGN, align);
+        }
+
+        // Layout the child.
+        let mut frames = self.child.layout(ctx, &pod, passed.chain(&styles))?;
+        for (region, frame) in regions.iter().zip(&mut frames) {
+            // Align in the target size. The target size depends on whether we
+            // should expand.
+            let target = regions.expand.select(region, frame.size);
+            let default = Spec::new(Align::Left, Align::Top);
+            let aligns = self.aligns.unwrap_or(default);
+            Arc::make_mut(frame).resize(target, aligns);
+        }
+
+        Ok(frames)
+    }
+}
+
+dynamic! {
+    Align: "alignment",
+}
+
+dynamic! {
+    Spec<Align>: "2d alignment",
+}
+
+castable! {
+    Spec<Option<Align>>,
+    Expected: "1d or 2d alignment",
+    @align: Align => {
+        let mut aligns = Spec::default();
+        aligns.set(align.axis(), Some(*align));
+        aligns
+    },
+    @aligns: Spec<Align> => aligns.map(Some),
+}