Evaluation and node-based layouting 🚀

1 files changed, 52 insertions, 0 deletions

diff --git a/src/layout/nodes/document.rs b/src/layout/nodes/document.rs
new file mode 100644
index 00000000..af7a31e6
--- /dev/null
+++ b/src/layout/nodes/document.rs
@@ -0,0 +1,52 @@
+use super::*;
+
+/// The top-level layouting node.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Document {
+    pub runs: Vec<Pages>,
+}
+
+impl Document {
+    /// Create a new document.
+    pub fn new() -> Self {
+        Self { runs: vec![] }
+    }
+
+    /// Layout the document.
+    pub async fn layout(&self, ctx: &mut LayoutContext) -> Vec<BoxLayout> {
+        let mut layouts = vec![];
+        for run in &self.runs {
+            layouts.extend(run.layout(ctx).await);
+        }
+        layouts
+    }
+}
+
+/// A variable-length run of pages that all have the same properties.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Pages {
+    /// The size of the pages.
+    pub size: Size,
+    /// The layout node that produces the actual pages.
+    pub child: LayoutNode,
+}
+
+impl Pages {
+    /// Layout the page run.
+    pub async fn layout(&self, ctx: &mut LayoutContext) -> Vec<BoxLayout> {
+        let constraints = LayoutConstraints {
+            spaces: vec![LayoutSpace { base: self.size, size: self.size }],
+            repeat: true,
+        };
+
+        self.child
+            .layout(ctx, constraints)
+            .await
+            .into_iter()
+            .filter_map(|item| match item {
+                LayoutItem::Spacing(_) => None,
+                LayoutItem::Box(layout, _) => Some(layout),
+            })
+            .collect()
+    }
+}