Add `Runtime` concept to abstract caching

1 files changed, 13 insertions, 6 deletions

diff --git a/src/layout.rs b/src/layout.rs
index 011f859a..481b4166 100644
--- a/src/layout.rs
+++ b/src/layout.rs
@@ -19,8 +19,16 @@ pub struct Layout<'a> {
 }
 
 impl<'a> Layout<'a> {
-    pub(crate) fn new(layout: &'a result::Layout, parent_position: Point) -> Self {
-        let position = parent_position + Vector::new(layout.location.x, layout.location.y);
+    pub(crate) fn new(layout: &'a result::Layout) -> Self {
+        Self::with_parent_position(layout, Point::new(0.0, 0.0))
+    }
+
+    fn with_parent_position(
+        layout: &'a result::Layout,
+        parent_position: Point,
+    ) -> Self {
+        let position =
+            parent_position + Vector::new(layout.location.x, layout.location.y);
 
         Layout { layout, position }
     }
@@ -47,9 +55,8 @@ impl<'a> Layout<'a> {
     /// [`Layout`]: struct.Layout.html
     /// [`Node`]: struct.Node.html
     pub fn children(&'a self) -> impl Iterator<Item = Layout<'a>> {
-        self.layout
-            .children
-            .iter()
-            .map(move |layout| Layout::new(layout, self.position))
+        self.layout.children.iter().map(move |layout| {
+            Layout::with_parent_position(layout, self.position)
+        })
     }
 }