From 29c3c7f1676925cdc2eed7ee95370b6260e912ec Mon Sep 17 00:00:00 2001
From: Sam Becker <sam@sambecker.com>
Date: Wed, 26 Mar 2025 22:34:50 -0500
Subject: [PATCH] Decouple faded scroll component from behavior

---
 src/components/FadedScroll.tsx         | 53 +++++---------------------
 src/components/cmdk/CommandKClient.tsx | 20 +++++-----
 src/components/useFadedScroll.ts       | 38 ++++++++++++++++++
 3 files changed, 58 insertions(+), 53 deletions(-)
 create mode 100644 src/components/useFadedScroll.ts

diff --git a/src/components/FadedScroll.tsx b/src/components/FadedScroll.tsx
index 4e940027..d16fd9b3 100644
--- a/src/components/FadedScroll.tsx
+++ b/src/components/FadedScroll.tsx
@@ -1,20 +1,15 @@
 import clsx from 'clsx/lite';
-import {
-  HTMLAttributes,
-  RefObject,
-  useEffect,
-  useMemo,
-  useRef,
-  useState,
-} from 'react';
+import { HTMLAttributes, RefObject } from 'react';
+import useFadedScroll from './useFadedScroll';
 
 export default function FadedScroll({
-  ref: containerRef,
+  ref,
   direction = 'vertical',
   fadeHeight = 24,
   hideScrollbar,
   className,
   classNameContent,
+  style,
   children,
   ...props
 }: HTMLAttributes<HTMLDivElement> & {
@@ -24,52 +19,22 @@ export default function FadedScroll({
   classNameContent?: string
   hideScrollbar?: boolean
 }) {
-  const contentRef = useRef<HTMLDivElement>(null);
-
-  const [position, setPosition] = useState<'start' | 'middle' | 'end'>('start');
-
-  const isVertical = direction === 'vertical';
-
-  useEffect(() => {
-    const ref = contentRef.current;
-    if (ref) {
-      const handleScroll = () => {
-        const isStart = isVertical
-          ? ref.scrollTop === 0
-          : ref.scrollLeft === 0;
-        const isEnd = isVertical
-          ? ref.scrollHeight - ref.scrollTop === ref.clientHeight
-          : ref.scrollWidth - ref.scrollLeft === ref.clientWidth;
-        setPosition(isStart ? 'start' : isEnd ? 'end' : 'middle');
-      };
-      ref.addEventListener('scroll', handleScroll);
-      return () => ref.removeEventListener('scroll', handleScroll);
-    }
-  }, [isVertical]);
-
-  const maskImage = useMemo(() => {
-    // eslint-disable-next-line max-len
-    let mask = `linear-gradient(to ${isVertical ? 'bottom' : 'right'}, transparent, black `;
-    mask += `${position !== 'start' ? fadeHeight : 0}px, black calc(100% - `;
-    mask += `${position !== 'end' ? fadeHeight : 0}px), transparent)`;
-    return mask;
-  }, [fadeHeight, isVertical, position]);
+  const { maskImage } = useFadedScroll(ref, direction, fadeHeight);
 
   return <div
     {...props}
-    ref={containerRef}
+    ref={ref}
     className={clsx(
-      isVertical
+      direction === 'vertical'
         ? 'overflow-y-hidden'
         : 'overflow-x-hidden',
       className,
     )}
-    style={{ maskImage }}
+    style={{ maskImage, ...style }}
   >
     <div
-      ref={contentRef}
       className={clsx(
-        isVertical
+        direction === 'vertical'
           ? 'max-h-full overflow-y-auto'
           : 'max-w-full overflow-x-auto',
         hideScrollbar && '[scrollbar-width:none]',
diff --git a/src/components/cmdk/CommandKClient.tsx b/src/components/cmdk/CommandKClient.tsx
index 1b225372..6cbae9f6 100644
--- a/src/components/cmdk/CommandKClient.tsx
+++ b/src/components/cmdk/CommandKClient.tsx
@@ -155,7 +155,7 @@ export default function CommandKClient({
 
   const ref = useRef<HTMLInputElement>(null);
   const mobileViewportHeight = useVisualViewportHeight();
-  const heightMinimum = '20rem';
+  const heightMinimum = '18rem';
   const maxHeight = useMemo(() => {
     const positionY = ref.current?.getBoundingClientRect().y;
     return mobileViewportHeight && positionY
@@ -573,14 +573,16 @@ export default function CommandKClient({
               </span>}
           </div>
         </div>
-        <Command.List className={clsx(
-          'relative overflow-y-auto',
-          'mx-3 pt-3',
-        )} style={{
-          maxHeight,
-          // eslint-disable-next-line max-len
-          maskImage: 'linear-gradient(to bottom, transparent, black 20px, black calc(100% - 20px), transparent)',
-        }}>
+        <Command.List
+          className={clsx(
+            'overflow-y-auto',
+            'mx-3 pt-3',
+          )} style={{
+            maxHeight,
+            // eslint-disable-next-line max-len
+            maskImage: 'linear-gradient(to bottom, transparent, black 20px, black calc(100% - 20px), transparent)',
+          }}
+        >
           <div className="pb-1 md:pb-2">
             <Command.Empty className="mt-1 pl-3 text-dim pb-4">
               {isLoading ? 'Searching ...' : 'No results found'}
diff --git a/src/components/useFadedScroll.ts b/src/components/useFadedScroll.ts
new file mode 100644
index 00000000..7e9bd50a
--- /dev/null
+++ b/src/components/useFadedScroll.ts
@@ -0,0 +1,38 @@
+import { RefObject, useEffect, useMemo, useState } from 'react';
+
+export default function useFadedScroll(
+  containerRef?: RefObject<HTMLDivElement | null>,
+  direction: 'vertical' | 'horizontal' = 'vertical',
+  fadeHeight = 24,
+) {
+  const [position, setPosition] = useState<'start' | 'middle' | 'end'>('start');
+
+  const isVertical = direction === 'vertical';
+
+  const ref = containerRef?.current?.children[0] as HTMLElement;
+  useEffect(() => {
+    if (ref) {
+      const handleScroll = () => {
+        const isStart = isVertical
+          ? ref.scrollTop === 0
+          : ref.scrollLeft === 0;
+        const isEnd = isVertical
+          ? ref.scrollHeight - ref.scrollTop === ref.clientHeight
+          : ref.scrollWidth - ref.scrollLeft === ref.clientWidth;
+        setPosition(isStart ? 'start' : isEnd ? 'end' : 'middle');
+      };
+      ref.addEventListener('scroll', handleScroll);
+      return () => ref.removeEventListener('scroll', handleScroll);
+    }
+  }, [ref, isVertical]);
+
+  const maskImage = useMemo(() => {
+    // eslint-disable-next-line max-len
+    let mask = `linear-gradient(to ${isVertical ? 'bottom' : 'right'}, transparent, black `;
+    mask += `${position !== 'start' ? fadeHeight : 0}px, black calc(100% - `;
+    mask += `${position !== 'end' ? fadeHeight : 0}px), transparent)`;
+    return mask;
+  }, [fadeHeight, isVertical, position]);
+
+  return { maskImage };
+}