Fix wheel animation for zero-crossing and countdown

entry_types/scrolled/package/spec/contentElements/counter/useWheelCharacters-spec.js

@@ -65,12 +65,23 @@ describe('createWheelCharacterFunctions', () => {
     ]);
   });
 
-  it('hides minus sign when transitioning to negative', () => {
+  it('hides minus sign when transitioning to negative integer', () => {
     const result = getRotationValues({value: -0.4, startValue: 0, targetValue: -1});
 
     expect(result[0]).toEqual({text: '-', hide: true});
   });
 
+  it('shows minus sign for small negative values with decimal places', () => {
+    const result = getRotationValues({
+      value: -0.1,
+      startValue: 0,
+      targetValue: -0.5,
+      decimalPlaces: 1
+    });
+
+    expect(result[0]).toEqual({text: '-', hide: false});
+  });
+
   it('includes hidden minus sign at start when counting to negative', () => {
     const result = getRotationValues({value: 10, startValue: 10, targetValue: -10});
 
@@ -127,7 +138,7 @@ describe('createWheelCharacterFunctions', () => {
     });
 
     expect(result).toEqual([
-      {value: 1, hideZero: false},
+      {value: 1, hideZero: true},
       {text: ',', hide: false},
       {value: 2, hideZero: false},
       {value: 3, hideZero: false},
@@ -161,4 +172,94 @@ describe('createWheelCharacterFunctions', () => {
     expect(values[2]).toBe(0.5); // tens: 1 → 0 (99 rotations), at halfway = 0.5
     expect(values[3]).toBe(5);   // ones: 0 → 0 (99 rotations), at halfway = 5
   });
+
+  it('animates digits when counting down from 10 to 9', () => {
+    const result = getRotationValues({value: 9.5, startValue: 10, targetValue: 9});
+
+    expect(result.map(r => r.value)).toEqual([0.5, 9.5]);
+  });
+
+  it('keeps hideZero true while digit value is below 1 when counting up past threshold', () => {
+    const result = getRotationValues({value: 10, startValue: 9, targetValue: 15});
+
+    expect(result[0].hideZero).toBe(true);
+    expect(result[0].value).toBeCloseTo(1 / 6);
+  });
+
+  it('does not hide middle zero at end when digit completes full rotation', () => {
+    const result = getRotationValues({value: 100, startValue: 0, targetValue: 100});
+
+    expect(result[1].hideZero).toBe(false);
+    expect(result[1].value).toBe(0);
+  });
+
+  it('does not hide middle zero at end when start was not a leading zero', () => {
+    const result = getRotationValues({value: 100, startValue: 10, targetValue: 100});
+
+    expect(result[1].hideZero).toBe(false);
+    expect(result[1].value).toBe(0);
+  });
+
+  it('shows correct final digit when crossing zero from negative to positive', () => {
+    const result = getRotationValues({value: 9, startValue: -10, targetValue: 9});
+
+    // tens digit should be 0, not 0.9
+    expect(result[1].value).toBe(0);
+    expect(result[2].value).toBe(9);
+  });
+
+  it('shows correct final digit when crossing zero from positive to negative', () => {
+    const result = getRotationValues({value: -9, startValue: 10, targetValue: -9});
+
+    expect(result[1].value).toBe(0);
+    expect(result[2].value).toBe(9);
+  });
+
+  it('works with decimal places when counting from 0 to 0.5', () => {
+    const result = getRotationValues({
+      value: 0.5,
+      startValue: 0,
+      targetValue: 0.5,
+      decimalPlaces: 1,
+      locale: 'en'
+    });
+
+    expect(result).toEqual([
+      {value: 0, hideZero: false},
+      {text: '.'},
+      {value: 5, hideZero: false}
+    ]);
+  });
+
+  it('handles floating point precision when counting to 0.7', () => {
+    const result = getRotationValues({
+      value: 0.7,
+      startValue: 0,
+      targetValue: 0.7,
+      decimalPlaces: 1,
+      locale: 'en'
+    });
+
+    expect(result).toEqual([
+      {value: 0, hideZero: false},
+      {text: '.'},
+      {value: 7, hideZero: false}
+    ]);
+  });
+
+  it('does not hide leading digit at start when counting down from 1900 to 0', () => {
+    const result = getRotationValues({value: 1900, startValue: 1900, targetValue: 0});
+
+    // thousands digit should not have hideZero at value 1900
+    expect(result[0].hideZero).toBe(false);
+    expect(result[0].value).toBe(1);
+  });
+
+  it('hides thousands digit at value 1000 when counting down from 1900', () => {
+    const result = getRotationValues({value: 1000, startValue: 1900, targetValue: 0});
+
+    // at 1000, the "0" coming in on the thousands wheel should be hidden
+    // since it will become a leading zero
+    expect(result[0].hideZero).toBe(true);
+  });
 });

entry_types/scrolled/package/src/contentElements/counter/WheelNumber.module.css

@@ -29,5 +29,4 @@
 
 .hidden {
   opacity: 0;
-  transition: none;
 }

entry_types/scrolled/package/src/contentElements/counter/useWheelCharacters.js

@@ -1,6 +1,17 @@
 import {useMemo} from 'react';
 
-export function createWheelCharacterFunctions({startValue, targetValue, decimalPlaces = 0, locale = 'en', useGrouping = false}) {
+export function useWheelCharacters({
+  startValue, targetValue, decimalPlaces = 0, locale = 'en', useGrouping = false
+}) {
+  return useMemo(
+    () => createWheelCharacterFunctions({startValue, targetValue, decimalPlaces, locale, useGrouping}),
+    [startValue, targetValue, decimalPlaces, locale, useGrouping]
+  );
+}
+
+export function createWheelCharacterFunctions({
+  startValue, targetValue, decimalPlaces = 0, locale = 'en', useGrouping = false
+}) {
   const hasNegative = startValue < 0 || targetValue < 0;
   const crossesZero = (startValue > 0 && targetValue < 0) || (startValue < 0 && targetValue > 0);
   const absStartValue = Math.abs(startValue);
@@ -9,8 +20,6 @@ export function createWheelCharacterFunctions({startValue, targetValue, decimalP
     String(Math.round(absTargetValue)).length,
     String(Math.round(absStartValue)).length
   );
-  const delta = absTargetValue - absStartValue;
-  const range = targetValue - startValue;
 
   const formatted = absTargetValue.toLocaleString(locale, {
     minimumIntegerDigits: integerDigitCount,
@@ -19,55 +28,65 @@ export function createWheelCharacterFunctions({startValue, targetValue, decimalP
     useGrouping
   });
 
-  const charFunctions = [];
   let digitIndex = 0;
 
-  for (const char of formatted) {
+  const charFunctions = [...formatted].map((char) => {
     if (/\d/.test(char)) {
-      const position = integerDigitCount - 1 - digitIndex;
+      const position = integerDigitCount - digitIndex++ - 1;
       const divisor = Math.pow(10, position);
 
       if (crossesZero) {
-        charFunctions.push((absValue) => ({
-          value: (absValue / divisor) % 10,
-          hideZero: position > 0 && absValue < divisor
-        }));
-      } else {
-        const startDigit = Math.floor(absStartValue / divisor) % 10;
-        const endDigit = Math.floor(absTargetValue / divisor) % 10;
-        const fullRotations = Math.floor(absTargetValue / (divisor * 10)) -
-                              Math.floor(absStartValue / (divisor * 10));
-        let distance = endDigit - startDigit + fullRotations * 10;
-        if (delta < 0 && endDigit > startDigit) distance -= 10;
+        const toZero = createDigitCharFunction(position, divisor, absStartValue, 0);
+        const fromZero = createDigitCharFunction(position, divisor, 0, absTargetValue);
+        const inFirstSegment = (value) => startValue < 0 ? value < 0 : value > 0;
 
-        charFunctions.push((absValue, progress) => ({
-          value: ((startDigit + progress * distance) % 10 + 10) % 10,
-          hideZero: position > 0 && absValue < divisor
-        }));
+        return (value, progress) =>
+          inFirstSegment(value) ?
+            toZero(value, (value - startValue) / -startValue) :
+            fromZero(value, value / targetValue);
+      } else {
+        return createDigitCharFunction(position, divisor, absStartValue, absTargetValue);
       }
-      digitIndex++;
     } else if (digitIndex < integerDigitCount) {
       const threshold = Math.pow(10, integerDigitCount - digitIndex);
-      charFunctions.push((absValue) => ({text: char, hide: absValue < threshold}));
+      return (value) => ({text: char, hide: Math.abs(value) < threshold});
     } else {
-      charFunctions.push(() => ({text: char}));
+      return () => ({text: char});
     }
-  }
+  });
 
   if (hasNegative) {
-    charFunctions.unshift((absValue, progress, value) => ({text: '-', hide: value > -1}));
+    const minusThreshold = -Math.pow(10, -decimalPlaces);
+    charFunctions.unshift((value) => ({text: '-', hide: value > minusThreshold}));
   }
 
+  const range = targetValue - startValue;
+
   return (value) => {
-    const absValue = Math.abs(value);
     const progress = range === 0 ? 0 : (value - startValue) / range;
-    return charFunctions.map(fn => fn(absValue, progress, value));
+    return charFunctions.map(fn => fn(value, progress));
   };
 }
 
-export function useWheelCharacters({startValue, targetValue, decimalPlaces = 0, locale = 'en', useGrouping = false}) {
-  return useMemo(
-    () => createWheelCharacterFunctions({startValue, targetValue, decimalPlaces, locale, useGrouping}),
-    [startValue, targetValue, decimalPlaces, locale, useGrouping]
-  );
+function createDigitCharFunction(position, divisor, segmentStart, segmentEnd) {
+  const startDigit = getDigitAtPosition(segmentStart, divisor);
+  const endDigit = getDigitAtPosition(segmentEnd, divisor);
+  const fullRotations = Math.floor(segmentEnd / (divisor * 10)) -
+                        Math.floor(segmentStart / (divisor * 10));
+  const distance = endDigit - startDigit + fullRotations * 10;
+
+  return (value, progress) => ({
+    value: ((startDigit + progress * distance) % 10 + 10) % 10,
+    hideZero: position > 0 && Math.abs(value) < divisor * 1.9
+  });
+}
+
+function getDigitAtPosition(value, divisor) {
+  // Multiply by integer instead of dividing by fraction to avoid floating point errors
+  // (e.g., 0.7 / 0.1 = 6.999... but 0.7 * 10 = 7)
+  if (divisor < 1) {
+    const multiplier = Math.round(1 / divisor);
+    return Math.floor(value * multiplier) % 10;
+  }
+  return Math.floor(value / divisor) % 10;
 }