1 files changed, 135 insertions, 0 deletions
diff --git a/src/library/layout.rs b/src/library/layout.rs
new file mode 100644
index 00000000..fb8633b1
--- /dev/null
+++ b/src/library/layout.rs
@@ -0,0 +1,135 @@
+use smallvec::smallvec;
+use super::*;
+
+
+function! {
+    /// `align`: Aligns content along the layouting axes.
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct AlignFunc {
+        body: Option<SyntaxModel>,
+        map: PosAxisMap<AlignmentValue>,
+    }
+
+    parse(header, body, ctx, errors, decos) {
+        AlignFunc {
+            body: body!(opt: body, ctx, errors, decos),
+            map: PosAxisMap::parse::<AxisKey, AlignmentValue>(errors, &mut header.args),
+        }
+    }
+
+    layout(self, ctx, errors) {
+        ctx.base = ctx.spaces[0].dimensions;
+
+        let map = self.map.dedup(errors, ctx.axes, |alignment| alignment.axis(ctx.axes));
+        for &axis in &[Primary, Secondary] {
+            if let Some(Spanned { v: alignment, span }) = map.get_spanned(axis) {
+                if let Some(generic) = alignment.to_generic(ctx.axes, axis) {
+                    *ctx.alignment.get_mut(axis) = generic;
+                } else {
+                    errors.push(err!(span;
+                        "invalid alignment `{}` for {} axis", alignment, axis));
+                }
+            }
+        }
+
+        match &self.body {
+            Some(body) => {
+                let layouted = layout(body, ctx).await;
+                errors.extend(layouted.errors);
+                vec![AddMultiple(layouted.output)]
+            }
+            None => vec![SetAlignment(ctx.alignment)],
+        }
+    }
+}
+
+function! {
+    /// `direction`: Sets the directions of the layouting axes.
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct DirectionFunc {
+        name_span: Span,
+        body: Option<SyntaxModel>,
+        map: PosAxisMap<Direction>,
+    }
+
+    parse(header, body, ctx, errors, decos) {
+        DirectionFunc {
+            name_span: header.name.span,
+            body: body!(opt: body, ctx, errors, decos),
+            map: PosAxisMap::parse::<AxisKey, Direction>(errors, &mut header.args),
+        }
+    }
+
+    layout(self, ctx, errors) {
+        ctx.base = ctx.spaces[0].dimensions;
+
+        let map = self.map.dedup(errors, ctx.axes, |direction| {
+            Some(direction.axis().to_generic(ctx.axes))
+        });
+
+        let mut axes = ctx.axes;
+
+        map.with(Primary, |&dir| axes.primary = dir);
+        map.with(Secondary, |&dir| axes.secondary = dir);
+
+        if axes.primary.axis() == axes.secondary.axis() {
+            errors.push(err!(self.name_span;
+                "invalid aligned primary and secondary axes: `{}`, `{}`",
+                ctx.axes.primary, ctx.axes.secondary));
+        } else {
+            ctx.axes = axes;
+        }
+
+        match &self.body {
+            Some(body) => {
+                let layouted = layout(body, ctx).await;
+                errors.extend(layouted.errors);
+                vec![AddMultiple(layouted.output)]
+            }
+            None => vec![SetAxes(ctx.axes)],
+        }
+    }
+}
+
+function! {
+    /// `box`: Layouts content into a box.
+    #[derive(Debug, Clone, PartialEq)]
+    pub struct BoxFunc {
+        body: SyntaxModel,
+        extents: AxisMap<PSize>,
+        debug: Option<bool>,
+    }
+
+    parse(header, body, ctx, errors, decos) {
+        BoxFunc {
+            body: body!(opt: body, ctx, errors, decos).unwrap_or(SyntaxModel::new()),
+            extents: AxisMap::parse::<ExtentKey, PSize>(errors, &mut header.args.key),
+            debug: header.args.key.get::<bool>(errors, "debug"),
+        }
+    }
+
+    layout(self, ctx, errors) {
+        ctx.repeat = false;
+        ctx.spaces.truncate(1);
+
+        if let Some(debug) = self.debug {
+            ctx.debug = debug;
+        }
+
+        let map = self.extents.dedup(errors, ctx.axes);
+        for &axis in &[Horizontal, Vertical] {
+            if let Some(psize) = map.get(axis) {
+                let size = psize.scaled(ctx.base.get(axis));
+                *ctx.base.get_mut(axis) = size;
+                *ctx.spaces[0].dimensions.get_mut(axis) = size;
+                *ctx.spaces[0].expansion.get_mut(axis) = true;
+            }
+        }
+
+        let layouted = layout(&self.body, ctx).await;
+        let layout = layouted.output.into_iter().next().unwrap();
+        errors.extend(layouted.errors);
+
+        vec![Add(layout)]
+    }
+}