Get the read-only set point signal more simply

Invalid attempts to specify a regulator's set point are now local to
each view of the regulator, and don't affect the regulator model. In
particular, a regulator will be valid and in force even when one of its
regulator input views is showing an invalid specification attempt. The
invalidity indicator should therefore be tied to the input showing
the invalid specification, not to the whole regulator outline item.

app-proto/main.css

@@ -3,7 +3,8 @@
   --text-bright: white;
   --text-invalid: #f58fc2; /* bright pink */
   --border: #555; /* light gray */
-  --border-focus: #aaa; /* bright gray */
+  --border-focus-dark: #aaa; /* bright gray */
+  --border-focus-light: white;
   --border-invalid: #70495c; /* dusky pink */
   --selection-highlight: #444; /* medium gray */
   --page-background: #222; /* dark gray */
@@ -23,7 +24,7 @@ body {
   display: flex;
   flex-direction: column;
   float: left;
-  width: 450px;
+  width: 500px;
   height: 100vh;
   margin: 0px;
   padding: 0px;
@@ -77,12 +78,12 @@ summary.selected {
   background-color: var(--selection-highlight);
 }
 
-summary > div, .constraint {
+summary > div, .regulator {
   padding-top: 4px;
   padding-bottom: 4px;
 }
 
-.element, .constraint {
+.element, .regulator {
   display: flex;
   flex-grow: 1;
   padding-left: 8px;
@@ -107,7 +108,7 @@ details[open]:has(li) .element-switch::after {
   flex-grow: 1;
 }
 
-.constraint-label {
+.regulator-label {
   flex-grow: 1;
 }
 
@@ -123,26 +124,34 @@ details[open]:has(li) .element-switch::after {
   width: 56px;
 }
 
-.constraint {
+.regulator {
   font-style: italic;
 }
 
-.constraint.invalid {
-  color: var(--text-invalid);
+.regulator-type {
+  padding: 2px 8px 0px 8px;
+  font-size: 10pt;
 }
 
-.constraint > input[type=checkbox] {
-  margin: 0px 8px 0px 0px;
-}
-
-.constraint > input[type=text] {
+.regulator-input {
   color: inherit;
   background-color: inherit;
   border: 1px solid var(--border);
   border-radius: 2px;
 }
 
-.constraint.invalid > input[type=text] {
+.regulator-input::placeholder {
+  color: inherit;
+  opacity: 54%;
+  font-style: italic;
+}
+
+.regulator-input.constraint {
+  background-color: var(--display-background);
+}
+
+.regulator-input.invalid {
+  color: var(--text-invalid);
   border-color: var(--border-invalid);
 }
 
@@ -154,7 +163,7 @@ details[open]:has(li) .element-switch::after {
   font-style: normal;
 }
 
-.invalid > .status::after, details:has(.invalid):not([open]) .status::after {
+.regulator-input.invalid + .status::after, details:has(.invalid):not([open]) .status::after {
   content: '⚠';
   color: var(--text-invalid);
 }
@@ -171,5 +180,11 @@ canvas {
 }
 
 canvas:focus {
-  border-color: var(--border-focus);
+  border-color: var(--border-focus-dark);
+  outline: none;
+}
+
+input:focus {
+  border-color: var(--border-focus-light);
+  outline: none;
 }

app-proto/src/add_remove.rs

@@ -1,7 +1,14 @@
 use sycamore::prelude::*;
 use web_sys::{console, wasm_bindgen::JsValue};
 
-use crate::{engine, AppState, assembly::{Assembly, Constraint, Element}};
+use crate::{
+    engine,
+    AppState,
+    assembly::{
+        Assembly,
+        Element
+    }
+};
 
 /* DEBUG */
 // load an example assembly for testing. this code will be removed once we've
@@ -190,44 +197,8 @@ pub fn AddRemove() -> View {
                             (subject_vec[0].clone(), subject_vec[1].clone())
                         }
                     );
-                    let lorentz_prod = create_signal(0.0);
-                    let lorentz_prod_valid = create_signal(false);
-                    let active = create_signal(true);
-                    state.assembly.insert_constraint(Constraint {
-                        subjects: subjects,
-                        lorentz_prod: lorentz_prod,
-                        lorentz_prod_text: create_signal(String::new()),
-                        lorentz_prod_valid: lorentz_prod_valid,
-                        active: active,
-                    });
+                    state.assembly.insert_new_regulator(subjects);
                     state.selection.update(|sel| sel.clear());
-                    
-                    /* DEBUG */
-                    // print updated constraint list
-                    console::log_1(&JsValue::from("Constraints:"));
-                    state.assembly.constraints.with(|csts| {
-                        for (_, cst) in csts.into_iter() {
-                            console::log_5(
-                                &JsValue::from(" "),
-                                &JsValue::from(cst.subjects.0),
-                                &JsValue::from(cst.subjects.1),
-                                &JsValue::from(":"),
-                                &JsValue::from(cst.lorentz_prod.get_untracked())
-                            );
-                        }
-                    });
-                    
-                    // update the realization when the constraint becomes active
-                    // and valid, or is edited while active and valid
-                    create_effect(move || {
-                        console::log_1(&JsValue::from(
-                            format!("Constraint ({}, {}) updated", subjects.0, subjects.1)
-                        ));
-                        lorentz_prod.track();
-                        if active.get() && lorentz_prod_valid.get() {
-                            state.assembly.realize();
-                        }
-                    });
                 }
             ) { "🔗" }
             select(bind:value=assembly_name) { /* DEBUG */ // example assembly chooser

app-proto/src/assembly.rs

@@ -5,11 +5,11 @@ use std::{collections::BTreeSet, sync::atomic::{AtomicU64, Ordering}};
 use sycamore::prelude::*;
 use web_sys::{console, wasm_bindgen::JsValue}; /* DEBUG */
 
-use crate::engine::{realize_gram, local_unif_to_std, ConfigSubspace, PartialMatrix};
+use crate::engine::{Q, local_unif_to_std, realize_gram, ConfigSubspace, PartialMatrix};
 
-// the types of the keys we use to access an assembly's elements and constraints
+// the types of the keys we use to access an assembly's elements and regulators
 pub type ElementKey = usize;
-pub type ConstraintKey = usize;
+pub type RegulatorKey = usize;
 
 pub type ElementColor = [f32; 3];
 
@@ -26,7 +26,7 @@ pub struct Element {
     pub label: String,
     pub color: ElementColor,
     pub representation: Signal<DVector<f64>>,
-    pub constraints: Signal<BTreeSet<ConstraintKey>>,
+    pub regulators: Signal<BTreeSet<RegulatorKey>>,
 
     // a serial number, assigned by `Element::new`, that uniquely identifies
     // each element
@@ -61,7 +61,7 @@ impl Element {
             label: label,
             color: color,
             representation: create_signal(representation),
-            constraints: create_signal(BTreeSet::default()),
+            regulators: create_signal(BTreeSet::default()),
             serial: serial,
             column_index: None
         }
@@ -111,13 +111,43 @@ impl Element {
     }
 }
 
-#[derive(Clone)]
-pub struct Constraint {
+// `set_point_spec` is always a valid specification of `set_point`
+//   ┌────────────┬─────────────────────────────────────────────────────┐
+//   │`set_point` │ `set_point_spec`                                    │
+//   ┝━━━━━━━━━━━━┿━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━┥
+//   │`Some(x)`   │ a string that parses to the floating-point value `x`│
+//   ├────────────┼─────────────────────────────────────────────────────┤
+//   │`None`      │ the empty string                                    │
+//   └────────────┴─────────────────────────────────────────────────────┘
+#[derive(Clone, Copy)]
+pub struct Regulator {
     pub subjects: (ElementKey, ElementKey),
-    pub lorentz_prod: Signal<f64>,
-    pub lorentz_prod_text: Signal<String>,
-    pub lorentz_prod_valid: Signal<bool>,
-    pub active: Signal<bool>
+    pub measurement: ReadSignal<f64>,
+    pub set_point: ReadSignal<Option<f64>>,
+    
+    set_point_writable: Signal<Option<f64>>,
+    set_point_spec: Signal<String>
+}
+
+impl Regulator {
+    pub fn get_set_point_spec_clone(&self) -> String {
+        self.set_point_spec.get_clone()
+    }
+    
+    pub fn get_set_point_spec_clone_untracked(&self) -> String {
+        self.set_point_spec.get_clone_untracked()
+    }
+    
+    pub fn try_specify_set_point(&self, spec: String) -> bool {
+        match spec.parse::<f64>() {
+            Err(_) if !spec.is_empty() => false,
+            set_pt => {
+                self.set_point_writable.set(set_pt.ok());
+                self.set_point_spec.set(spec);
+                true
+            }
+        }
+    }
 }
 
 // the velocity is expressed in uniform coordinates
@@ -131,9 +161,9 @@ type AssemblyMotion<'a> = Vec<ElementMotion<'a>>;
 // a complete, view-independent description of an assembly
 #[derive(Clone)]
 pub struct Assembly {
-    // elements and constraints
+    // elements and regulators
     pub elements: Signal<Slab<Element>>,
-    pub constraints: Signal<Slab<Constraint>>,
+    pub regulators: Signal<Slab<Regulator>>,
     
     // solution variety tangent space. the basis vectors are stored in
     // configuration matrix format, ordered according to the elements' column
@@ -155,13 +185,13 @@ impl Assembly {
     pub fn new() -> Assembly {
         Assembly {
             elements: create_signal(Slab::new()),
-            constraints: create_signal(Slab::new()),
+            regulators: create_signal(Slab::new()),
             tangent: create_signal(ConfigSubspace::zero(0)),
             elements_by_id: create_signal(FxHashMap::default())
         }
     }
     
-    // --- inserting elements and constraints ---
+    // --- inserting elements and regulators ---
     
     // insert an element into the assembly without checking whether we already
     // have an element with the same identifier. any element that does have the
@@ -204,14 +234,62 @@ impl Assembly {
         );
     }
     
-    pub fn insert_constraint(&self, constraint: Constraint) {
-        let subjects = constraint.subjects;
-        let key = self.constraints.update(|csts| csts.insert(constraint));
-        let subject_constraints = self.elements.with(
-            |elts| (elts[subjects.0].constraints, elts[subjects.1].constraints)
+    pub fn insert_regulator(&self, regulator: Regulator) {
+        let subjects = regulator.subjects;
+        let key = self.regulators.update(|regs| regs.insert(regulator));
+        let subject_regulators = self.elements.with(
+            |elts| (elts[subjects.0].regulators, elts[subjects.1].regulators)
         );
-        subject_constraints.0.update(|csts| csts.insert(key));
-        subject_constraints.1.update(|csts| csts.insert(key));
+        subject_regulators.0.update(|regs| regs.insert(key));
+        subject_regulators.1.update(|regs| regs.insert(key));
+    }
+    
+    pub fn insert_new_regulator(self, subjects: (ElementKey, ElementKey)) {
+        // create and insert a new regulator
+        let measurement = self.elements.map(
+            move |elts| {
+                let reps = (
+                    elts[subjects.0].representation.get_clone(),
+                    elts[subjects.1].representation.get_clone()
+                );
+                reps.0.dot(&(&*Q * reps.1))
+            }
+        );
+        let set_point_writable = create_signal(None);
+        let set_point = *set_point_writable;
+        self.insert_regulator(Regulator {
+            subjects: subjects,
+            measurement: measurement,
+            set_point: set_point,
+            set_point_writable: set_point_writable,
+            set_point_spec: create_signal(String::new())
+        });
+        
+        /* DEBUG */
+        // print updated regulator list
+        console::log_1(&JsValue::from("Regulators:"));
+        self.regulators.with(|regs| {
+            for (_, reg) in regs.into_iter() {
+                console::log_5(
+                    &JsValue::from(" "),
+                    &JsValue::from(reg.subjects.0),
+                    &JsValue::from(reg.subjects.1),
+                    &JsValue::from(":"),
+                    &JsValue::from(reg.set_point.get_untracked())
+                );
+            }
+        });
+        
+        // update the realization when the regulator becomes a constraint, or is
+        // edited while acting as a constraint
+        create_effect(move || {
+            console::log_1(&JsValue::from(
+                format!("Updated constraint with subjects ({}, {})", subjects.0, subjects.1)
+            ));
+            if set_point.with(|set_pt| set_pt.is_some()) {
+                self.realize();
+            }
+        });
     }
     
     // --- realization ---
@@ -228,13 +306,16 @@ impl Assembly {
         let (gram, guess) = self.elements.with_untracked(|elts| {
             // set up the off-diagonal part of the Gram matrix
             let mut gram_to_be = PartialMatrix::new();
-            self.constraints.with_untracked(|csts| {
-                for (_, cst) in csts {
-                    if cst.active.get_untracked() && cst.lorentz_prod_valid.get_untracked() {
-                        let subjects = cst.subjects;
-                        let row = elts[subjects.0].column_index.unwrap();
-                        let col = elts[subjects.1].column_index.unwrap();
-                        gram_to_be.push_sym(row, col, cst.lorentz_prod.get_untracked());
+            self.regulators.with_untracked(|regs| {
+                for (_, reg) in regs {
+                    match reg.set_point.get_untracked() {
+                        Some(set_pt) => {
+                            let subjects = reg.subjects;
+                            let row = elts[subjects.0].column_index.unwrap();
+                            let col = elts[subjects.1].column_index.unwrap();
+                            gram_to_be.push_sym(row, col, set_pt);
+                        },
+                        None => ()
                     }
                 }
             });

app-proto/src/outline.rs

@@ -1,56 +1,87 @@
 use itertools::Itertools;
 use sycamore::prelude::*;
 use web_sys::{
-    Event,
-    HtmlInputElement,
     KeyboardEvent,
     MouseEvent,
     wasm_bindgen::JsCast
 };
 
-use crate::{AppState, assembly, assembly::{Constraint, ConstraintKey, ElementKey}};
+use crate::{
+    AppState,
+    assembly,
+    assembly::{
+        Regulator,
+        RegulatorKey,
+        ElementKey
+    }
+};
 
-// an editable view of the Lorentz product representing a constraint
+// an editable view of a regulator
 #[component(inline_props)]
-fn LorentzProductInput(constraint: Constraint) -> View {
+fn RegulatorInput(regulator: Regulator) -> View {
+    let valid = create_signal(true);
+    let value = create_signal(regulator.get_set_point_spec_clone_untracked());
+    
+    // this closure resets the input value to the regulator's set point
+    // specification, which is always a valid specification
+    let reset_value = move || {
+        batch(|| {
+            valid.set(true);
+            value.set(regulator.get_set_point_spec_clone());
+        })
+    };
+    
+    // reset the input value whenever the regulator's set point specification
+    // is updated
+    create_effect(reset_value);
+    
     view! {
         input(
             r#type="text",
-            bind:value=constraint.lorentz_prod_text,
-            on:change=move |event: Event| {
-                let target: HtmlInputElement = event.target().unwrap().unchecked_into();
-                match target.value().parse::<f64>() {
-                    Ok(lorentz_prod) => batch(|| {
-                        constraint.lorentz_prod.set(lorentz_prod);
-                        constraint.lorentz_prod_valid.set(true);
-                    }),
-                    Err(_) => constraint.lorentz_prod_valid.set(false)
-                };
+            class=move || {
+                if valid.get() {
+                    match regulator.set_point.get() {
+                        Some(_) => "regulator-input constraint",
+                        None => "regulator-input"
+                    }
+                } else {
+                    "regulator-input invalid"
+                }
+            },
+            placeholder=regulator.measurement.with(|result| result.to_string()),
+            bind:value=value,
+            on:change=move |_| valid.set(
+                regulator.try_specify_set_point(value.get_clone_untracked())
+            ),
+            on:keydown={
+                move |event: KeyboardEvent| {
+                    match event.key().as_str() {
+                        "Escape" => reset_value(),
+                        _ => ()
+                    }
+                }
             }
         )
     }
 }
 
-// a list item that shows a constraint in an outline view of an element
+// a list item that shows a regulator in an outline view of an element
 #[component(inline_props)]
-fn ConstraintOutlineItem(constraint_key: ConstraintKey, element_key: ElementKey) -> View {
+fn RegulatorOutlineItem(regulator_key: RegulatorKey, element_key: ElementKey) -> View {
     let state = use_context::<AppState>();
     let assembly = &state.assembly;
-    let constraint = assembly.constraints.with(|csts| csts[constraint_key].clone());
-    let other_subject = if constraint.subjects.0 == element_key {
-        constraint.subjects.1
+    let regulator = assembly.regulators.with(|regs| regs[regulator_key]);
+    let other_subject = if regulator.subjects.0 == element_key {
+        regulator.subjects.1
     } else {
-        constraint.subjects.0
+        regulator.subjects.0
     };
     let other_subject_label = assembly.elements.with(|elts| elts[other_subject].label.clone());
-    let class = constraint.lorentz_prod_valid.map(
-        |&lorentz_prod_valid| if lorentz_prod_valid { "constraint" } else { "constraint invalid" }
-    );
     view! {
-        li(class=class.get()) {
-            input(r#type="checkbox", bind:checked=constraint.active)
-            div(class="constraint-label") { (other_subject_label) }
-            LorentzProductInput(constraint=constraint)
+        li(class="regulator") {
+            div(class="regulator-label") { (other_subject_label) }
+            div(class="regulator-type") { "Inversive distance" }
+            RegulatorInput(regulator=regulator)
             div(class="status")
         }
     }
@@ -74,9 +105,9 @@ fn ElementOutlineItem(key: ElementKey, element: assembly::Element) -> View {
             ).collect::<Vec<_>>()
         )
     };
-    let constrained = element.constraints.map(|csts| csts.len() > 0);
-    let constraint_list = element.constraints.map(
-        |csts| csts.clone().into_iter().collect()
+    let regulated = element.regulators.map(|regs| regs.len() > 0);
+    let regulator_list = element.regulators.map(
+        |regs| regs.clone().into_iter().collect()
     );
     let details_node = create_node_ref();
     view! {
@@ -91,7 +122,7 @@ fn ElementOutlineItem(key: ElementKey, element: assembly::Element) -> View {
                                     state.select(key, event.shift_key());
                                     event.prevent_default();
                                 },
-                                "ArrowRight" if constrained.get() => {
+                                "ArrowRight" if regulated.get() => {
                                     let _ = details_node
                                         .get()
                                         .unchecked_into::<web_sys::Element>()
@@ -138,16 +169,16 @@ fn ElementOutlineItem(key: ElementKey, element: assembly::Element) -> View {
                         div(class="status")
                     }
                 }
-                ul(class="constraints") {
+                ul(class="regulators") {
                     Keyed(
-                        list=constraint_list,
-                        view=move |cst_key| view! {
-                            ConstraintOutlineItem(
-                                constraint_key=cst_key,
+                        list=regulator_list,
+                        view=move |reg_key| view! {
+                            RegulatorOutlineItem(
+                                regulator_key=reg_key,
                                 element_key=key
                             )
                         },
-                        key=|cst_key| cst_key.clone()
+                        key=|reg_key| reg_key.clone()
                     )
                 }
             }
@@ -155,9 +186,9 @@ fn ElementOutlineItem(key: ElementKey, element: assembly::Element) -> View {
     }
 }
 
-// a component that lists the elements of the current assembly, showing the
-// constraints on each element as a collapsible sub-list. its implementation
-// is based on Kate Morley's HTML + CSS tree views:
+// a component that lists the elements of the current assembly, showing each
+// element's regulators in a collapsible sub-list. its implementation is based
+// on Kate Morley's HTML + CSS tree views:
 //
 //   https://iamkate.com/code/tree-views/
 //