From ee8a01b9cb7e27a697baeb4211ed50936c1b9ebe Mon Sep 17 00:00:00 2001
From: Aaron Fenyes <aaron.fenyes@fareycircles.ooo>
Date: Thu, 17 Apr 2025 13:20:50 -0700
Subject: [PATCH] Let regulators handle their own activation

This improves code organization at the cost of a little redundancy: the
default implementation of `activate` doesn't do anything, and its
implementation for `HalfCurvatureRegulator` redundantly accesses the
set point signal and checks whether the regulator is set.
---
 app-proto/src/assembly.rs | 58 ++++++++++++++++++---------------------
 1 file changed, 27 insertions(+), 31 deletions(-)

diff --git a/app-proto/src/assembly.rs b/app-proto/src/assembly.rs
index 055b9a2..aedc344 100644
--- a/app-proto/src/assembly.rs
+++ b/app-proto/src/assembly.rs
@@ -145,6 +145,8 @@ pub trait Regulator: ProblemPoser + OutlineItem {
     fn subjects(&self) -> Vec<ElementKey>;
     fn measurement(&self) -> ReadSignal<f64>;
     fn set_point(&self) -> Signal<SpecifiedValue>;
+    
+    fn activate(&self, _assembly: &Assembly) {}
 }
 
 pub struct ProductRegulator {
@@ -202,6 +204,17 @@ impl Regulator for HalfCurvatureRegulator {
     fn set_point(&self) -> Signal<SpecifiedValue> {
         self.set_point
     }
+    
+    fn activate(&self, assembly: &Assembly) {
+        if let Some(half_curv) = self.set_point.with_untracked(|set_pt| set_pt.value) {
+            let representation = assembly.elements.with_untracked(
+                |elts| elts[self.subject].representation
+            );
+            representation.update(
+                |rep| change_half_curvature(rep, half_curv)
+            );
+        }
+    }
 }
 
 impl ProblemPoser for HalfCurvatureRegulator {
@@ -313,7 +326,7 @@ impl Assembly {
     fn insert_regulator(&self, regulator: Rc<dyn Regulator>) {
         let subjects = regulator.subjects();
         let key = self.regulators.update(
-            |regs| regs.insert(regulator)
+            |regs| regs.insert(regulator.clone())
         );
         let subject_regulators: Vec<_> = self.elements.with_untracked(
             |elts| subjects.into_iter().map(
@@ -324,6 +337,19 @@ impl Assembly {
             regulators.update(|regs| regs.insert(key));
         }
         
+        // update the realization when the regulator becomes a constraint, or is
+        // edited while acting as a constraint
+        let self_for_effect = self.clone();
+        create_effect(move || {
+            console::log_1(&JsValue::from(
+                format!("Updated regulator with subjects {:?}", regulator.subjects())
+            ));
+            if regulator.set_point().with(|set_pt| set_pt.is_present()) {
+                regulator.activate(&self_for_effect);
+                self_for_effect.realize();
+            }
+        });
+        
         /* DEBUG */
         // print an updated list of regulators
         console::log_1(&JsValue::from("Regulators:"));
@@ -365,18 +391,6 @@ impl Assembly {
             measurement: measurement,
             set_point: set_point
         }));
-        
-        // update the realization when the regulator becomes a constraint, or is
-        // edited while acting as a constraint
-        let self_for_effect = self.clone();
-        create_effect(move || {
-            console::log_1(&JsValue::from(
-                format!("Updated regulator with subjects {:?}", subjects)
-            ));
-            if set_point.with(|set_pt| set_pt.is_present()) {
-                self_for_effect.realize();
-            }
-        });
     }
     
     pub fn insert_new_half_curvature_regulator(&self, subject: ElementKey) {
@@ -390,24 +404,6 @@ impl Assembly {
             measurement: measurement,
             set_point: set_point
         }));
-        
-        // update the realization when the regulator becomes a constraint, or is
-        // edited while acting as a constraint
-        let self_for_effect = self.clone();
-        create_effect(move || {
-            console::log_1(&JsValue::from(
-                format!("Updated regulator with subjects [{}]", subject)
-            ));
-            if let Some(half_curv) = set_point.with(|set_pt| set_pt.value) {
-                let representation = self_for_effect.elements.with_untracked(
-                    |elts| elts[subject].representation
-                );
-                representation.update(
-                    |rep| change_half_curvature(rep, half_curv)
-                );
-                self_for_effect.realize();
-            }
-        });
     }
     
     // --- realization ---