From fa9f78b46e3a2270a44d4cc0691195a7c695cb93 Mon Sep 17 00:00:00 2001
From: Samuel Gunter <29130894+Samathingamajig@users.noreply.github.com>
Date: Sun, 23 Mar 2025 19:49:11 -0500
Subject: [PATCH] feat: sticky calendar header and days (#568)

* feat: sticky calendar days

* feat: partial height borders for day labels

* feat: make calendar header actually sticky

* fix: remove unneeded gap

* refactor: add preston as co-author

Co-authored-by: Preston-Cook <preston.l.cook@gmail.com>

* fix: z-index issues with export sub-buttons

---------

Co-authored-by: Preston-Cook <preston.l.cook@gmail.com>
Co-authored-by: doprz <52579214+doprz@users.noreply.github.com>
---
 src/views/components/calendar/Calendar.tsx    |  4 +-
 .../components/calendar/CalendarGrid.tsx      | 41 +++++++++++++------
 .../components/calendar/CalendarGridCell.tsx  |  4 +-
 .../CalendarHeader/CalendarHeader.tsx         |  4 +-
 .../tests/useFlattenedCourseSchedule.test.ts  |  2 +-
 src/views/hooks/useFlattenedCourseSchedule.ts |  4 +-
 6 files changed, 39 insertions(+), 20 deletions(-)

diff --git a/src/views/components/calendar/Calendar.tsx b/src/views/components/calendar/Calendar.tsx
index 0715cf75..f2402e9c 100644
--- a/src/views/components/calendar/Calendar.tsx
+++ b/src/views/components/calendar/Calendar.tsx
@@ -140,7 +140,7 @@ export default function Calendar(): JSX.Element {
                                 // scrollbarGutter: 'stable',
                             }
                         }
-                        className='h-full flex flex-grow flex-col overflow-x-scroll px-spacing-5'
+                        className='z-1 h-full flex flex-grow flex-col overflow-x-scroll [&>*]:px-spacing-5'
                     >
                         <CalendarHeader
                             sidebarOpen={showSidebar}
@@ -148,7 +148,7 @@ export default function Calendar(): JSX.Element {
                                 setShowSidebar(!showSidebar);
                             }}
                         />
-                        <div className='min-h-2xl min-w-5xl flex-grow overflow-auto pl-spacing-3 pt-spacing-3 screenshot:min-h-xl'>
+                        <div className='min-h-2xl min-w-5xl flex-grow gap-0 pl-spacing-3 screenshot:min-h-xl'>
                             <CalendarGrid courseCells={courseCells} setCourse={setCourse} />
                         </div>
                         <CalendarBottomBar courseCells={courseCells} setCourse={setCourse} />
diff --git a/src/views/components/calendar/CalendarGrid.tsx b/src/views/components/calendar/CalendarGrid.tsx
index fd97ba6b..938e188e 100644
--- a/src/views/components/calendar/CalendarGrid.tsx
+++ b/src/views/components/calendar/CalendarGrid.tsx
@@ -3,7 +3,7 @@ import CalendarCourseCell from '@views/components/calendar/CalendarCourseCell';
 import Text from '@views/components/common/Text/Text';
 import { ColorPickerProvider } from '@views/contexts/ColorPickerContext';
 import type { CalendarGridCourse } from '@views/hooks/useFlattenedCourseSchedule';
-import React from 'react';
+import React, { Fragment } from 'react';
 
 import CalendarCell from './CalendarGridCell';
 
@@ -30,13 +30,13 @@ function makeGridRow(row: number, cols: number): JSX.Element {
     const hour = hoursOfDay[row]!;
 
     return (
-        <>
+        <Fragment key={row}>
             <CalendarHour hour={hour} />
             <div className='grid-row-span-2 w-4 border-b border-r border-gray-300' />
             {[...Array(cols).keys()].map(col => (
                 <CalendarCell key={`${row}${col}`} row={row} col={col} />
             ))}
-        </>
+        </Fragment>
     );
 }
 
@@ -56,23 +56,40 @@ export default function CalendarGrid({
     setCourse,
 }: React.PropsWithChildren<Props>): JSX.Element {
     return (
-        <div className='grid grid-cols-[auto_auto_repeat(5,1fr)] grid-rows-[auto_repeat(26,1fr)] h-full'>
+        <div className='grid grid-cols-[auto_auto_repeat(5,1fr)] grid-rows-[auto_auto_repeat(27,1fr)] h-full'>
+            {/* Cover top left corner of grid, so time gets cut off at the top of the partial border */}
+            <div className='sticky top-[85px] z-10 col-span-2 h-3 bg-white' />
             {/* Displaying day labels */}
-            <div />
-            <div className='w-4 border-b border-r border-gray-300' />
             {daysOfWeek.map(day => (
-                <div className='h-4 flex items-end justify-center border-b border-r border-gray-300 pb-1.5'>
-                    <Text key={day} variant='small' className='text-center text-ut-burntorange' as='div'>
-                        {day}
-                    </Text>
+                <div
+                    // Full height with background to prevent grid lines from showing behind
+                    className='sticky top-[85px] z-10 row-span-2 h-7 flex flex-col items-end self-start justify-end bg-white'
+                    key={day}
+                >
+                    {/* Partial border height because that's what Isaiah wants */}
+                    <div className='h-4 w-full flex items-end border-b border-r border-gray-300'>
+                        {/* Alignment for text */}
+                        <div className='h-[calc(1.75rem_-_1px)] w-full flex items-center justify-center'>
+                            <Text variant='small' className='text-center text-ut-burntorange' as='div'>
+                                {day}
+                            </Text>
+                        </div>
+                    </div>
                 </div>
             ))}
+            {/* empty slot, for alignment */}
+            <div />
+            {/* time tick for the first hour */}
+            <div className='h-4 w-4 self-end border-b border-r border-gray-300' />
             {[...Array(13).keys()].map(i => makeGridRow(i, 5))}
             <CalendarHour hour={21} />
             {Array(6)
                 .fill(1)
-                .map(() => (
-                    <div className='h-4 flex items-end justify-center border-r border-gray-300' />
+                .map((_, i) => (
+                    // Key suppresses warning about duplicate keys,
+                    // and index is fine because it doesn't change between renders
+                    // eslint-disable-next-line react/no-array-index-key
+                    <div key={i} className='h-4 flex items-end justify-center border-r border-gray-300' />
                 ))}
             <ColorPickerProvider>
                 {courseCells && <AccountForCourseConflicts courseCells={courseCells} setCourse={setCourse} />}
diff --git a/src/views/components/calendar/CalendarGridCell.tsx b/src/views/components/calendar/CalendarGridCell.tsx
index 334e0151..a010872a 100644
--- a/src/views/components/calendar/CalendarGridCell.tsx
+++ b/src/views/components/calendar/CalendarGridCell.tsx
@@ -17,8 +17,8 @@ function CalendarCell({ row, col }: Props): JSX.Element {
         <div
             className='h-full w-full flex items-center border-b border-r border-gray-300'
             style={{
-                gridColumn: col + 3,
-                gridRow: `${2 * row + 2} / ${2 * row + 4}`,
+                gridColumn: col + 3, // start in the 3rd 1-index column
+                gridRow: `${2 * row + 3} / ${2 * row + 5}`, // Span 2 rows, skip 2 header rows
             }}
         >
             <div className='h-0 w-full border-t border-gray-300/25' />
diff --git a/src/views/components/calendar/CalendarHeader/CalendarHeader.tsx b/src/views/components/calendar/CalendarHeader/CalendarHeader.tsx
index b4e7f314..8990cb56 100644
--- a/src/views/components/calendar/CalendarHeader/CalendarHeader.tsx
+++ b/src/views/components/calendar/CalendarHeader/CalendarHeader.tsx
@@ -27,7 +27,7 @@ export default function CalendarHeader({ sidebarOpen, onSidebarToggle }: Calenda
     return (
         <div
             style={{ scrollbarGutter: 'stable' }}
-            className='sticky left-0 right-0 min-h-[85px] flex items-center gap-5 overflow-x-scroll overflow-y-hidden pl-spacing-7 pt-spacing-5'
+            className='sticky left-0 right-0 top-0 z-10 min-h-[85px] flex items-center gap-5 overflow-x-scroll overflow-y-hidden bg-white pl-spacing-7 pt-spacing-5'
         >
             {!sidebarOpen && (
                 <Button
@@ -62,7 +62,7 @@ export default function CalendarHeader({ sidebarOpen, onSidebarToggle }: Calenda
                                 className={clsx([
                                     styleResetClass,
                                     'mt-spacing-3',
-                                    'min-w-max cursor-pointer origin-top-right rounded bg-white p-1 text-black shadow-lg transition border border-ut-offwhite/50 focus:outline-none',
+                                    'min-w-max cursor-pointer origin-top-right rounded bg-white p-1 text-black shadow-lg transition border border-ut-offwhite/50 focus:outline-none z-20',
                                     'data-[closed]:(opacity-0 scale-95)',
                                     'data-[enter]:(ease-out-expo duration-150)',
                                     'data-[leave]:(ease-out duration-50)',
diff --git a/src/views/hooks/tests/useFlattenedCourseSchedule.test.ts b/src/views/hooks/tests/useFlattenedCourseSchedule.test.ts
index 1b1feb51..f00ba112 100644
--- a/src/views/hooks/tests/useFlattenedCourseSchedule.test.ts
+++ b/src/views/hooks/tests/useFlattenedCourseSchedule.test.ts
@@ -5,7 +5,7 @@ import { convertMinutesToIndex } from '../useFlattenedCourseSchedule';
 describe('useFlattenedCourseSchedule', () => {
     it('should convert minutes to index correctly', () => {
         const minutes = 480; // 8:00 AM
-        const expectedIndex = 2; // (480 - 420) / 30 = 2
+        const expectedIndex = 3; // (480 - 480) / 30 + 2 + 1 = 3
         const result = convertMinutesToIndex(minutes);
         expect(result).toBe(expectedIndex);
     });
diff --git a/src/views/hooks/useFlattenedCourseSchedule.ts b/src/views/hooks/useFlattenedCourseSchedule.ts
index 6ca28583..3d3138a4 100644
--- a/src/views/hooks/useFlattenedCourseSchedule.ts
+++ b/src/views/hooks/useFlattenedCourseSchedule.ts
@@ -52,7 +52,9 @@ export interface FlattenedCourseSchedule {
  * @param minutes - The number of minutes.
  * @returns The index value.
  */
-export const convertMinutesToIndex = (minutes: number): number => Math.floor((minutes - 420) / 30);
+export const convertMinutesToIndex = (minutes: number): number =>
+    // 480 = 8 a.m., 30 = 30 minute slots, 2 header rows, and grid rows start at 1
+    Math.floor((minutes - 480) / 30) + 2 + 1;
 
 /**
  * Get the active schedule, and convert it to be render-able into a calendar.