fix: matrix choice selector

src/components/ChoiceSelect/ChoiceSelect.tsx

@@ -28,17 +28,13 @@ function ChoiceSelect<T extends string>({
 
     if (currentIndex === -1 || options.length === 0) return;
 
-    const nextIndex =
-      (currentIndex + direction + options.length) % options.length;
+    const nextIndex = (currentIndex + direction + options.length) % options.length;
 
     onChange(options[nextIndex]);
   };
 
   return (
-    <div
-      className={`choice-select ${className}`}
-      data-disabled={disabled || undefined}
-    >
+    <div className={`choice-select ${className}`} data-disabled={disabled || undefined}>
       <select
         id={id}
         className="choice-select__input"

src/components/ChoiceStepper/ChoiceStepper.css

@@ -36,6 +36,7 @@
 
 .choice-stepper__arrows {
   flex: 0 0 auto;
+  align-self: stretch;
 
   display: flex;
   flex-direction: column;

src/components/ChoiceStepper/ChoiceStepper.tsx

@@ -1,8 +1,17 @@
-import { JSX, useEffect, useState } from 'react';
+import { JSX, useEffect, useRef, useState } from 'react';
 import Button from '../Button/Button';
 import { TriangleUpIcon, TriangleDownIcon } from '../../assets/icons/Triangle';
 import './ChoiceStepper.css';
 
+const WHEEL_COMMIT_DELAY = 250;
+// Safety net: if the parent's `value` prop never comes back exactly equal
+// to what we committed (rounding, an intermediate transform, etc.), stop
+// waiting after this long so the stepper doesn't get stuck ignoring
+// external updates.
+const PENDING_FALLBACK_MS = 1000;
+
+type CommitResult = Promise<boolean | void> | boolean | void;
+
 function StepperArrows({
   onUp,
   onDown,
@@ -44,7 +53,7 @@ type ChoiceStepperListProps<T> = {
   value: T;
   values: readonly T[];
   formatLabel: (value: T) => string;
-  onChange: (value: T) => void;
+  onChange: (value: T) => CommitResult;
   id?: string;
   disabled?: boolean;
   className?: string;
@@ -59,38 +68,117 @@ function ChoiceStepperList<T>({
   disabled,
   className,
 }: ChoiceStepperListProps<T>) {
-  const index = values.indexOf(value);
+  const [localValue, setLocalValue] = useState(value);
+  const [text, setText] = useState(formatLabel(value));
+
+  // True from the moment a commit starts until the prop `value` we get from
+  // the parent actually reflects it (not just until onChange resolves —
+  // those are two different moments and the gap between them is what was
+  // causing the old-value blink).
+  const interacting = useRef(false);
+  // The value we're waiting to see echoed back via the `value` prop.
+  const pendingValue = useRef<T | null>(null);
+  const wheelTimeout = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const fallbackTimeout = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    if (interacting.current) {
+      // Only release control once the prop actually catches up to what we
+      // committed — otherwise keep showing localValue as-is (no flash back
+      // to the stale old value in between).
+      if (pendingValue.current !== null && Object.is(value, pendingValue.current)) {
+        interacting.current = false;
+        pendingValue.current = null;
+        if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+      } else {
+        return;
+      }
+    }
+    setLocalValue(value);
+    setText(formatLabel(value));
+  }, [value, formatLabel]);
+
+  useEffect(() => {
+    return () => {
+      if (wheelTimeout.current) clearTimeout(wheelTimeout.current);
+      if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+    };
+  }, []);
+
+  const index = values.indexOf(localValue);
   const canUp = index === -1 || index < values.length - 1;
   const canDown = index > 0;
 
-  const [text, setText] = useState(formatLabel(value));
-  useEffect(() => setText(formatLabel(value)), [value, formatLabel]);
-
-  const step = (direction: 1 | -1) => {
-    const currentIndex = values.indexOf(value);
-
-    if (currentIndex === -1) return;
+  const stepLocal = (direction: 1 | -1): T | null => {
+    const currentIndex = values.indexOf(localValue);
+    if (currentIndex === -1) return null;
 
     const nextIndex = currentIndex + direction;
+    if (nextIndex < 0 || nextIndex >= values.length) return null;
 
-    if (nextIndex >= 0 && nextIndex < values.length) {
-      onChange(values[nextIndex]);
+    const next = values[nextIndex];
+    setLocalValue(next);
+    setText(formatLabel(next));
+    return next;
+  };
+
+  async function commit(next: T) {
+    interacting.current = true;
+    pendingValue.current = next;
+
+    const result = await onChange(next);
+
+    if (result === false) {
+      interacting.current = false;
+      pendingValue.current = null;
+      if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+      setLocalValue(value);
+      setText(formatLabel(value));
+      return;
     }
+
+    // Accepted: don't clear `interacting` here. Wait for the prop-sync
+    // effect above to see `value === next` and release it, so we never
+    // hand control back to a still-stale prop. Guard with a timeout in
+    // case it never matches exactly.
+    if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+    fallbackTimeout.current = setTimeout(() => {
+      interacting.current = false;
+      pendingValue.current = null;
+    }, PENDING_FALLBACK_MS);
+  }
+
+  const stepAndCommit = (direction: 1 | -1) => {
+    const next = stepLocal(direction);
+    if (next !== null) void commit(next);
+  };
+
+  const stepWheel = (direction: 1 | -1) => {
+    const next = stepLocal(direction);
+    if (next === null) return;
+
+    interacting.current = true;
+    if (wheelTimeout.current) clearTimeout(wheelTimeout.current);
+    wheelTimeout.current = setTimeout(() => {
+      wheelTimeout.current = null;
+      void commit(next);
+    }, WHEEL_COMMIT_DELAY);
   };
 
   const commitText = () => {
     const match = values.find(
       (v) => formatLabel(v).trim().toLowerCase() === text.trim().toLowerCase()
     );
-    if (match !== undefined) onChange(match);
-    else setText(formatLabel(value));
+    if (match !== undefined) {
+      setLocalValue(match);
+      void commit(match);
+    } else {
+      setText(formatLabel(value));
+    }
   };
 
   return (
-    <div
-      className={`choice-stepper ${className ?? ''}`}
-      data-disabled={disabled || undefined}
-    >
+    <div className={`choice-stepper ${className ?? ''}`} data-disabled={disabled || undefined}>
       <input
         id={id}
         className="choice-stepper__input"
@@ -102,25 +190,32 @@ function ChoiceStepperList<T>({
           e.preventDefault();
 
           if (e.deltaY < 0 && canUp) {
-            step(1);
+            stepWheel(1);
           } else if (e.deltaY > 0 && canDown) {
-            step(-1);
+            stepWheel(-1);
           }
         }}
         onKeyDown={(e) => {
-          if (e.key === 'Enter') e.currentTarget.blur();
-          else if (e.key === 'ArrowUp') {
+          if (e.key === 'Enter') {
+            e.currentTarget.blur();
+          } else if (e.key === 'ArrowUp') {
             e.preventDefault();
-            step(1);
+            interacting.current = true;
+            stepLocal(1);
           } else if (e.key === 'ArrowDown') {
             e.preventDefault();
-            step(-1);
+            interacting.current = true;
+            stepLocal(-1);
           }
         }}
+        onKeyUp={(e) => {
+          if (e.key !== 'ArrowUp' && e.key !== 'ArrowDown') return;
+          void commit(localValue);
+        }}
       />
       <StepperArrows
-        onUp={() => step(1)}
-        onDown={() => step(-1)}
+        onUp={() => stepAndCommit(1)}
+        onDown={() => stepAndCommit(-1)}
         canUp={canUp}
         canDown={canDown}
         disabled={disabled}
@@ -137,7 +232,7 @@ type ChoiceStepperRangeProps = {
   max: number;
   step?: number;
   formatLabel: (value: number) => string;
-  onChange: (value: number) => void;
+  onChange: (value: number) => CommitResult;
   id?: string;
   disabled?: boolean;
   className?: string;
@@ -154,30 +249,100 @@ function ChoiceStepperRange({
   disabled,
   className,
 }: ChoiceStepperRangeProps) {
+  const [localValue, setLocalValue] = useState(value);
   const [text, setText] = useState(formatLabel(value));
-  useEffect(() => setText(formatLabel(value)), [value, formatLabel]);
+
+  const interacting = useRef(false);
+  const pendingValue = useRef<number | null>(null);
+  const wheelTimeout = useRef<ReturnType<typeof setTimeout> | null>(null);
+  const fallbackTimeout = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  useEffect(() => {
+    if (interacting.current) {
+      if (pendingValue.current !== null && Object.is(value, pendingValue.current)) {
+        interacting.current = false;
+        pendingValue.current = null;
+        if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+      } else {
+        return;
+      }
+    }
+    setLocalValue(value);
+    setText(formatLabel(value));
+  }, [value, formatLabel]);
+
+  useEffect(() => {
+    return () => {
+      if (wheelTimeout.current) clearTimeout(wheelTimeout.current);
+      if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+    };
+  }, []);
 
   const clamp = (n: number) => Math.min(max, Math.max(min, n));
 
-  const canUp = value < max;
-  const canDown = value > min;
+  const canUp = localValue < max;
+  const canDown = localValue > min;
 
-  const step = (direction: 1 | -1) => {
-    const next = clamp(value + direction * stepSize);
-    if (next !== value) onChange(next);
+  const stepLocal = (direction: 1 | -1): number | null => {
+    const next = clamp(localValue + direction * stepSize);
+    if (next === localValue) return null;
+    setLocalValue(next);
+    setText(formatLabel(next));
+    return next;
+  };
+
+  async function commit(next: number) {
+    interacting.current = true;
+    pendingValue.current = next;
+
+    const result = await onChange(next);
+
+    if (result === false) {
+      interacting.current = false;
+      pendingValue.current = null;
+      if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+      setLocalValue(value);
+      setText(formatLabel(value));
+      return;
+    }
+
+    if (fallbackTimeout.current) clearTimeout(fallbackTimeout.current);
+    fallbackTimeout.current = setTimeout(() => {
+      interacting.current = false;
+      pendingValue.current = null;
+    }, PENDING_FALLBACK_MS);
+  }
+
+  const stepAndCommit = (direction: 1 | -1) => {
+    const next = stepLocal(direction);
+    if (next !== null) void commit(next);
+  };
+
+  const stepWheel = (direction: 1 | -1) => {
+    const next = stepLocal(direction);
+    if (next === null) return;
+
+    interacting.current = true;
+    if (wheelTimeout.current) clearTimeout(wheelTimeout.current);
+    wheelTimeout.current = setTimeout(() => {
+      wheelTimeout.current = null;
+      void commit(next);
+    }, WHEEL_COMMIT_DELAY);
   };
 
   const commitText = () => {
     const parsed = Number(text);
-    if (Number.isFinite(parsed)) onChange(clamp(parsed));
-    else setText(formatLabel(value));
+    if (Number.isFinite(parsed)) {
+      const next = clamp(parsed);
+      setLocalValue(next);
+      void commit(next);
+    } else {
+      setText(formatLabel(value));
+    }
   };
 
   return (
-    <div
-      className={`choice-stepper ${className ?? ''}`}
-      data-disabled={disabled || undefined}
-    >
+    <div className={`choice-stepper ${className ?? ''}`} data-disabled={disabled || undefined}>
       <input
         id={id}
         className="choice-stepper__input"
@@ -189,9 +354,9 @@ function ChoiceStepperRange({
           e.preventDefault();
 
           if (e.deltaY < 0 && canUp) {
-            step(1);
+            stepWheel(1);
           } else if (e.deltaY > 0 && canDown) {
-            step(-1);
+            stepWheel(-1);
           }
         }}
         onKeyDown={(e) => {
@@ -199,16 +364,26 @@ function ChoiceStepperRange({
             e.currentTarget.blur();
           } else if (e.key === 'ArrowUp') {
             e.preventDefault();
-            if (canUp) step(1);
+            if (canUp) {
+              interacting.current = true;
+              stepLocal(1);
+            }
           } else if (e.key === 'ArrowDown') {
             e.preventDefault();
-            if (canDown) step(-1);
+            if (canDown) {
+              interacting.current = true;
+              stepLocal(-1);
             }
+          }
+        }}
+        onKeyUp={(e) => {
+          if (e.key !== 'ArrowUp' && e.key !== 'ArrowDown') return;
+          void commit(localValue);
         }}
       />
       <StepperArrows
-        onUp={() => step(1)}
-        onDown={() => step(-1)}
+        onUp={() => stepAndCommit(1)}
+        onDown={() => stepAndCommit(-1)}
         canUp={canUp}
         canDown={canDown}
         disabled={disabled}

src/features/dsp408/components/CompressorSection/CompressorSection.tsx

@@ -89,7 +89,7 @@ function CompressorPanel({
                 onLiveValue(channel, 'ratio', value);
                 commit({ ratio: value });
               }}
-/>
+            />
             <div className="compressor-panel__cell-label">Ratio</div>
           </div>
 
@@ -103,7 +103,7 @@ function CompressorPanel({
                 onLiveValue(channel, 'knee', value);
                 commit({ knee: value });
               }}
-/>
+            />
             <div className="compressor-panel__cell-label">Knee</div>
           </div>
         </div>

src/features/dsp408/components/LimiterSection/LimiterSection.tsx

@@ -206,10 +206,13 @@ function LimiterSection({ dsp, set_limiter }: { dsp: DSP; set_limiter: SetLimite
           <div className="limiter-graph__meters">
             {outputs.map((output) => {
               const outputState = dsp.state.current_config.output_states[output];
-              const idx = OUTPUT_METER_INDEX[output];
 
               return (
-                <MeterBar key={output} label={outputState.name} meter={dsp.meters.channels[idx]} />
+                <MeterBar
+                  key={output}
+                  label={outputState.name}
+                  meter={dsp.output_meters.meters[output]}
+                />
               );
             })}
           </div>

src/features/dsp408/components/Matrixsection/Matrixsection.css

@@ -92,7 +92,7 @@
 
 .matrix-panel__row .choice-stepper {
   align-self: center;
-  height: auto;
+  aspect-ratio: 3 / 1;
   flex: 0 0 auto;
 }
 
@@ -109,4 +109,11 @@
 
 .matrix-gain-stepper .choice-stepper__input {
   font-size: 2.8cqh;
+  text-align: center;
+}
+
+.matrix-gain-stepper .choice-stepper__arrows {
+  flex: 0 0 20%;
+  width: 20%;
+  padding-right: 0;
 }