From a4dd1e2f6e92f90c201287ea6a83a865a7f10d71 Mon Sep 17 00:00:00 2001
From: "Timothy Z." <timothy@stremio.com>
Date: Fri, 3 Jan 2025 13:26:30 +0200
Subject: [PATCH] feat(MultiSelectMenu): scroll into view

---
 .../MultiselectMenu/Dropdown/Dropdown.tsx     | 70 +++++++++++++------
 .../Dropdown/Option/Option.tsx                | 10 +--
 2 files changed, 53 insertions(+), 27 deletions(-)

diff --git a/src/common/MultiselectMenu/Dropdown/Dropdown.tsx b/src/common/MultiselectMenu/Dropdown/Dropdown.tsx
index cb7de76c2..eea0d679e 100644
--- a/src/common/MultiselectMenu/Dropdown/Dropdown.tsx
+++ b/src/common/MultiselectMenu/Dropdown/Dropdown.tsx
@@ -1,6 +1,6 @@
 // Copyright (C) 2017-2024 Smart code 203358507
 
-import React from 'react';
+import React, { useRef, useEffect, useCallback } from 'react';
 import Button from 'stremio/common/Button';
 import { useTranslation } from 'react-i18next';
 import classNames from 'classnames';
@@ -19,33 +19,57 @@ type Props = {
 
 const Dropdown = ({ level, setLevel, options, onSelect, selectedOption, menuOpen }: Props) => {
     const { t } = useTranslation();
+    const optionsRef = useRef(new Map());
+    const containerRef = useRef(null);
 
-    const onBackButtonClick = () => {
+    const handleSetOptionRef = useCallback((value: number) => (node: HTMLButtonElement | null) => {
+        if (node) {
+            optionsRef.current.set(value, node);
+        } else {
+            optionsRef.current.delete(value);
+        }
+    }, []);
+
+    const handleBackClick = useCallback(() => {
         setLevel(level - 1);
-    };
+    }, [setLevel, level]);
 
-    return (
-        <div className={classNames(styles['dropdown'], { [styles['open']]: menuOpen })} role={'listbox'}>
-            {
-                level > 0 ?
-                    <Button className={styles['back-button']} onClick={onBackButtonClick}>
-                        <Icon name={'caret-left'} className={styles['back-button-icon']} />
-                        {t('BACK')}
-                    </Button>
-                    : null
+    useEffect(() => {
+        if (menuOpen && selectedOption && containerRef.current) {
+            const selectedNode = optionsRef.current.get(selectedOption.value);
+            if (selectedNode) {
+                selectedNode.scrollIntoView({
+                    behavior: 'smooth',
+                    block: 'nearest'
+                });
             }
-            {
-                options
-                    .filter((option: MultiselectMenuOption) => !option.hidden)
-                    .map((option: MultiselectMenuOption, index) => (
-                        <Option
-                            key={index}
-                            option={option}
-                            onSelect={onSelect}
-                            selectedOption={selectedOption}
-                        />
-                    ))
+        }
+    }, [menuOpen, selectedOption]);
 
+    return (
+        <div
+            className={classNames(styles['dropdown'], { [styles['open']]: menuOpen })}
+            role={'listbox'}
+            ref={containerRef}
+        >
+            {level > 0 ?
+                <Button className={styles['back-button']} onClick={handleBackClick}>
+                    <Icon name={'caret-left'} className={styles['back-button-icon']} />
+                    {t('BACK')}
+                </Button>
+                : null
+            }
+            {options
+                .filter((option: MultiselectMenuOption) => !option.hidden)
+                .map((option: MultiselectMenuOption) => (
+                    <Option
+                        key={option.id}
+                        ref={handleSetOptionRef(option.value)}
+                        option={option}
+                        onSelect={onSelect}
+                        selectedOption={selectedOption}
+                    />
+                ))
             }
         </div>
     );
diff --git a/src/common/MultiselectMenu/Dropdown/Option/Option.tsx b/src/common/MultiselectMenu/Dropdown/Option/Option.tsx
index 13ea37bd5..3812282a2 100644
--- a/src/common/MultiselectMenu/Dropdown/Option/Option.tsx
+++ b/src/common/MultiselectMenu/Dropdown/Option/Option.tsx
@@ -1,6 +1,6 @@
 // Copyright (C) 2017-2024 Smart code 203358507
 
-import React, { useCallback, useMemo } from 'react';
+import React, { useCallback, useMemo, forwardRef } from 'react';
 import classNames from 'classnames';
 import Button from 'stremio/common/Button';
 import styles from './Option.less';
@@ -12,7 +12,7 @@ type Props = {
     onSelect: (value: number) => void;
 };
 
-const Option = ({ option, selectedOption, onSelect }: Props) => {
+const Option = forwardRef<HTMLButtonElement, Props>(({ option, selectedOption, onSelect }, ref) => {
     // consider using option.id === selectedOption?.id instead
     const selected = useMemo(() => option?.value === selectedOption?.value, [option, selectedOption]);
 
@@ -22,6 +22,7 @@ const Option = ({ option, selectedOption, onSelect }: Props) => {
 
     return (
         <Button
+            ref={ref}
             className={classNames(styles['option'], { [styles['selected']]: selected })}
             key={option.id}
             onClick={handleClick}
@@ -32,7 +33,6 @@ const Option = ({ option, selectedOption, onSelect }: Props) => {
                 selected && !option.level ?
                     <div className={styles['icon']} />
                     : null
-
             }
             {
                 option.level ?
@@ -41,6 +41,8 @@ const Option = ({ option, selectedOption, onSelect }: Props) => {
             }
         </Button>
     );
-};
+});
+
+Option.displayName = 'Option';
 
 export default Option;