Decouple iced from coffee

src/renderer.rs

@@ -0,0 +1,15 @@
+use crate::Layout;
+
+pub trait Renderer {
+    type Color: Copy;
+
+    /// Explains the [`Layout`] of an [`Element`] for debugging purposes.
+    ///
+    /// This will be called when [`Element::explain`] has been used. It should
+    /// _explain_ the [`Layout`] graphically.
+    ///
+    /// [`Layout`]: struct.Layout.html
+    /// [`Element`]: struct.Element.html
+    /// [`Element::explain`]: struct.Element.html#method.explain
+    fn explain(&mut self, layout: &Layout<'_>, color: Self::Color);
+}