From 0a09905f9f849ce9ff221095e5c25b231f040d27 Mon Sep 17 00:00:00 2001
From: Tom Butcher <thomasbutcher15@gmail.com>
Date: Thu, 20 Aug 2026 19:42:25 +0100
Subject: [PATCH] Enhance PermissionsMatrix with session storage for expanded
 rows and scroll position

- Implemented session storage functionality to persist expanded row keys and scroll position in the PermissionsMatrix, improving user experience during navigation.
- Refactored state management to utilize hooks for handling expanded rows and scroll restoration.
- Added utility functions for reading and writing to session storage, ensuring data integrity and availability across user sessions.
- Updated event handling for scroll events to maintain the user's scroll position, enhancing usability in the permissions matrix.
---
 .../Dashboard/common/PermissionsMatrix.jsx    | 109 +++++++++++++++---
 1 file changed, 96 insertions(+), 13 deletions(-)

diff --git a/src/components/Dashboard/common/PermissionsMatrix.jsx b/src/components/Dashboard/common/PermissionsMatrix.jsx
index 9353a8b1..c1cc4f80 100644
--- a/src/components/Dashboard/common/PermissionsMatrix.jsx
+++ b/src/components/Dashboard/common/PermissionsMatrix.jsx
@@ -4,7 +4,9 @@ import {
   useState,
   createElement,
   useContext,
-  useRef
+  useRef,
+  useEffect,
+  useLayoutEffect
 } from 'react'
 import PropTypes from 'prop-types'
 import { Table, Flex, Tooltip, Button } from 'antd'
@@ -21,6 +23,30 @@ import PermissionCheckbox from './PermissionCheckbox'
 import { CaretRightOutlined } from '@ant-design/icons'
 
 const DEFAULT_SCROLL_HEIGHT = 'calc(var(--unit-100vh) - 258px)'
+const PERMISSIONS_MATRIX_SESSION_KEY = 'permissionsMatrix:ui'
+
+const readPermissionsMatrixSession = () => {
+  try {
+    const parsed = JSON.parse(
+      sessionStorage.getItem(PERMISSIONS_MATRIX_SESSION_KEY)
+    )
+    if (!parsed || typeof parsed !== 'object') return {}
+    return parsed
+  } catch {
+    return {}
+  }
+}
+
+const writePermissionsMatrixSession = (patch) => {
+  try {
+    sessionStorage.setItem(
+      PERMISSIONS_MATRIX_SESSION_KEY,
+      JSON.stringify({ ...readPermissionsMatrixSession(), ...patch })
+    )
+  } catch {
+    // sessionStorage may be unavailable
+  }
+}
 
 const getColumnIndexProps = (columnIndex) => ({
   'data-col': String(columnIndex),
@@ -328,9 +354,26 @@ const PermissionsMatrix = ({
     () => buildPermissionMatrixDataSource(models),
     [models]
   )
-  const [expandedRowKeys, setExpandedRowKeys] = useState(null)
+  const [expandedRowKeys, setExpandedRowKeys] = useState(() => {
+    const stored = readPermissionsMatrixSession().expandedRowKeys
+    return Array.isArray(stored) ? stored : []
+  })
+  const matrixRef = useRef(null)
+  const scrollPositionRef = useRef(null)
+  if (scrollPositionRef.current === null) {
+    const storedScroll = readPermissionsMatrixSession().scroll
+    scrollPositionRef.current = {
+      left: Number(storedScroll?.left) || 0,
+      top: Number(storedScroll?.top) || 0
+    }
+  }
   const hoveredColumnIndexRef = useRef(null)
 
+  const persistExpandedRowKeys = useCallback((keys) => {
+    setExpandedRowKeys(keys)
+    writePermissionsMatrixSession({ expandedRowKeys: keys })
+  }, [])
+
   const handleMatrixMouseOver = useCallback((event) => {
     const cell = event.target.closest('.ant-table-cell')
     if (!cell || !event.currentTarget.contains(cell)) return
@@ -345,11 +388,44 @@ const PermissionsMatrix = ({
     event.currentTarget.style.removeProperty('--permissions-hovered-col')
   }, [])
 
-  const resolvedExpandedRowKeys = useMemo(
-    () => expandedRowKeys ?? dataSource.map((row) => row.key),
-    [dataSource, expandedRowKeys]
+  const resolvedExpandedRowKeys = useMemo(() => {
+    const sectionKeys = new Set(dataSource.map((row) => row.key))
+    return expandedRowKeys.filter((key) => sectionKeys.has(key))
+  }, [dataSource, expandedRowKeys])
+
+  const getTableBody = useCallback(
+    () => matrixRef.current?.querySelector('.ant-table-body') || null,
+    []
   )
 
+  const restoreTableScroll = useCallback(() => {
+    const body = getTableBody()
+    if (!body) return
+    body.scrollLeft = scrollPositionRef.current.left
+    body.scrollTop = scrollPositionRef.current.top
+  }, [getTableBody])
+
+  useLayoutEffect(() => {
+    restoreTableScroll()
+  }, [restoreTableScroll, resolvedExpandedRowKeys])
+
+  useEffect(() => {
+    const body = getTableBody()
+    if (!body) return
+
+    const handleScroll = (event) => {
+      const next = {
+        left: event.currentTarget.scrollLeft,
+        top: event.currentTarget.scrollTop
+      }
+      scrollPositionRef.current = next
+      writePermissionsMatrixSession({ scroll: next })
+    }
+
+    body.addEventListener('scroll', handleScroll, { passive: true })
+    return () => body.removeEventListener('scroll', handleScroll)
+  }, [getTableBody, resolvedExpandedRowKeys])
+
   const isSectionExpanded = useCallback(
     (record) => resolvedExpandedRowKeys.includes(record.key),
     [resolvedExpandedRowKeys]
@@ -358,14 +434,20 @@ const PermissionsMatrix = ({
   const handleToggleSection = useCallback(
     (record) => {
       if (!record.isGroup) return
-      setExpandedRowKeys((current) => {
-        const keys = current ?? dataSource.map((row) => row.key)
-        return keys.includes(record.key)
-          ? keys.filter((key) => key !== record.key)
-          : [...keys, record.key]
-      })
+      persistExpandedRowKeys(
+        expandedRowKeys.includes(record.key)
+          ? expandedRowKeys.filter((key) => key !== record.key)
+          : [...expandedRowKeys, record.key]
+      )
     },
-    [dataSource]
+    [expandedRowKeys, persistExpandedRowKeys]
+  )
+
+  const handleExpandedRowsChange = useCallback(
+    (keys) => {
+      persistExpandedRowKeys(keys)
+    },
+    [persistExpandedRowKeys]
   )
 
   var adjustedScrollHeight = scrollHeight
@@ -627,6 +709,7 @@ const PermissionsMatrix = ({
 
   return (
     <div
+      ref={matrixRef}
       className='permissions-matrix'
       onMouseOver={handleMatrixMouseOver}
       onMouseLeave={handleMatrixMouseLeave}
@@ -645,7 +728,7 @@ const PermissionsMatrix = ({
         }
         expandable={{
           expandedRowKeys: resolvedExpandedRowKeys,
-          onExpandedRowsChange: setExpandedRowKeys,
+          onExpandedRowsChange: handleExpandedRowsChange,
           indentSize: 0,
           expandIcon: () => null
         }}