Split text measurements cache from rendering cache

This speeds up layouting in the most common scenario considerably!
:tada:

1 files changed, 10 insertions, 1 deletions

diff --git a/native/src/renderer.rs b/native/src/renderer.rs
index 5963d577..833de571 100644
--- a/native/src/renderer.rs
+++ b/native/src/renderer.rs
@@ -26,6 +26,15 @@ mod windowed;
 pub use debugger::Debugger;
 pub use windowed::{Target, Windowed};
 
-pub trait Renderer {
+use crate::{layout, Element};
+
+pub trait Renderer: Sized {
     type Output;
+
+    fn layout<'a, Message>(
+        &mut self,
+        element: &Element<'a, Message, Self>,
+    ) -> layout::Node {
+        element.layout(self, &layout::Limits::NONE)
+    }
 }