From 57c970e22e85114443a06d1b69f6cbae2ebcbb2e Mon Sep 17 00:00:00 2001
From: Mikolaj Wielgus <wielgusmikolaj@gmail.com>
Date: Sun, 21 Jul 2024 14:49:43 +0200
Subject: [PATCH] drawing: obtain `HeadRef` via new trait for abstract
 reference objects

---
 src/drawing/band.rs  | 2 ++
 src/drawing/head.rs  | 9 +++------
 src/graph.rs         | 4 +++-
 src/router/router.rs | 2 +-
 4 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/src/drawing/band.rs b/src/drawing/band.rs
index b7d497a..202d9d9 100644
--- a/src/drawing/band.rs
+++ b/src/drawing/band.rs
@@ -5,3 +5,5 @@ pub enum BandFirstSegIndex {
     Straight(LoneLooseSegIndex),
     Bended(SeqLooseSegIndex),
 }
+
+pub struct BandRef {}
diff --git a/src/drawing/head.rs b/src/drawing/head.rs
index 1572d85..41d2a46 100644
--- a/src/drawing/head.rs
+++ b/src/drawing/head.rs
@@ -1,6 +1,6 @@
 use enum_dispatch::enum_dispatch;
 
-use crate::geometry::shape::MeasureLength;
+use crate::{geometry::shape::MeasureLength, graph::MakeRef};
 
 use super::{
     cane::Cane,
@@ -22,11 +22,8 @@ pub enum Head {
     Cane(CaneHead),
 }
 
-impl Head {
-    pub fn ref_<'a, CW: Copy, R: AccessRules>(
-        &self,
-        drawing: &'a Drawing<CW, R>,
-    ) -> HeadRef<'a, CW, R> {
+impl<'a, CW: Copy, R: AccessRules> MakeRef<'a, HeadRef<'a, CW, R>, Drawing<CW, R>> for Head {
+    fn ref_(&self, drawing: &'a Drawing<CW, R>) -> HeadRef<'a, CW, R> {
         HeadRef::new(*self, drawing)
     }
 }
diff --git a/src/graph.rs b/src/graph.rs
index b9d47c7..d83b858 100644
--- a/src/graph.rs
+++ b/src/graph.rs
@@ -6,7 +6,9 @@ use std::{
 use enum_dispatch::enum_dispatch;
 use petgraph::stable_graph::NodeIndex;
 
-// Due to apparent limitations of enum_dispatch we're forced to import some types backwards.
+pub trait MakeRef<'a, R: 'a, C> {
+    fn ref_(&self, context: &'a C) -> R;
+}
 
 #[enum_dispatch]
 pub trait GetPetgraphIndex {
diff --git a/src/router/router.rs b/src/router/router.rs
index d567214..8788078 100644
--- a/src/router/router.rs
+++ b/src/router/router.rs
@@ -16,7 +16,7 @@ use crate::{
         primitive::{AccessPrimitiveShape, PrimitiveShape},
         shape::{AccessShape, MeasureLength},
     },
-    graph::GetPetgraphIndex,
+    graph::{GetPetgraphIndex, MakeRef},
     layout::Layout,
 };