Refactor function parsing ♻

1 files changed, 53 insertions, 0 deletions

diff --git a/src/library/boxed.rs b/src/library/boxed.rs
new file mode 100644
index 00000000..909115d5
--- /dev/null
+++ b/src/library/boxed.rs
@@ -0,0 +1,53 @@
+use crate::length::ScaleLength;
+use super::*;
+
+/// `box`: Layouts its contents into a box.
+///
+/// # Keyword arguments
+/// - `width`: The width of the box (length of relative to parent's width).
+/// - `height`: The height of the box (length of relative to parent's height).
+pub fn boxed(call: FuncCall, state: &ParseState) -> Pass<SyntaxNode> {
+    let mut f = Feedback::new();
+    let mut args = call.header.args;
+    let node = BoxNode {
+        body: parse_body_maybe(call.body, state, &mut f).unwrap_or(SyntaxTree::new()),
+        width: args.key.get::<ScaleLength>("width", &mut f),
+        height: args.key.get::<ScaleLength>("height", &mut f),
+    };
+    drain_args(args, &mut f);
+    Pass::node(node, f)
+}
+
+#[derive(Debug, Clone, PartialEq)]
+struct BoxNode {
+    body: SyntaxTree,
+    width: Option<ScaleLength>,
+    height: Option<ScaleLength>,
+}
+
+#[async_trait(?Send)]
+impl Layout for BoxNode {
+    async fn layout<'a>(&'a self, mut ctx: LayoutContext<'_>) -> Pass<Commands<'a>> {
+        ctx.spaces.truncate(1);
+        ctx.repeat = false;
+
+        self.width.with(|v| {
+            let length = v.raw_scaled(ctx.base.x);
+            ctx.base.x = length;
+            ctx.spaces[0].size.x = length;
+            ctx.spaces[0].expansion.horizontal = true;
+        });
+
+        self.height.with(|v| {
+            let length = v.raw_scaled(ctx.base.y);
+            ctx.base.y = length;
+            ctx.spaces[0].size.y = length;
+            ctx.spaces[0].expansion.vertical = true;
+        });
+
+        layout(&self.body, ctx).await.map(|out| {
+            let layout = out.into_iter().next().unwrap();
+            vec![Add(layout)]
+        })
+    }
+}