From 5b4736aedab94458ca73a60b2a0ac5c4a82b3648 Mon Sep 17 00:00:00 2001
From: Kevin Wu <kevinwu098@gmail.com>
Date: Sat, 7 Dec 2024 22:58:49 -0800
Subject: [PATCH] feat: prevent rerender of SectionTableBody when hovered

---
 .../src/components/Calendar/CalendarRoot.tsx  | 20 +++----
 .../SectionTable/CourseInfoButton.tsx         |  6 +--
 .../SectionTable/SectionTableBody.tsx         | 54 +++++++++++--------
 .../src/stores/calendarizeHelpers.ts          | 12 ++---
 4 files changed, 47 insertions(+), 45 deletions(-)

diff --git a/apps/antalmanac/src/components/Calendar/CalendarRoot.tsx b/apps/antalmanac/src/components/Calendar/CalendarRoot.tsx
index 66d523d92..479b7c045 100644
--- a/apps/antalmanac/src/components/Calendar/CalendarRoot.tsx
+++ b/apps/antalmanac/src/components/Calendar/CalendarRoot.tsx
@@ -5,6 +5,7 @@ import { Box, ClickAwayListener, Popper } from '@material-ui/core';
 import moment from 'moment';
 import { memo, SyntheticEvent, useCallback, useEffect, useMemo, useState } from 'react';
 import { Calendar, DateLocalizer, momentLocalizer, Views } from 'react-big-calendar';
+import { shallow } from 'zustand/shallow';
 
 import CalendarToolbar from './CalendarToolbar';
 import CourseCalendarEvent, { CalendarEvent, CourseEvent } from './CourseCalendarEvent';
@@ -29,10 +30,10 @@ export const ScheduleCalendar = memo(() => {
     const [scheduleNames, setScheduleNames] = useState(() => AppStore.getScheduleNames());
 
     const { isMilitaryTime } = useTimeFormatStore();
-    const [hoveredCalendarizedCourses, hoveredCalendarizedFinal] = useHoveredStore((store) => [
-        store.hoveredCalendarizedCourses,
-        store.hoveredCalendarizedFinal,
-    ]);
+    const [hoveredCalendarizedCourses, hoveredCalendarizedFinal] = useHoveredStore(
+        (state) => [state.hoveredCalendarizedCourses, state.hoveredCalendarizedFinal],
+        shallow
+    );
 
     const getEventsForCalendar = useCallback((): CalendarEvent[] => {
         if (showFinalsSchedule)
@@ -49,6 +50,8 @@ export const ScheduleCalendar = memo(() => {
         showFinalsSchedule,
     ]);
 
+    const events = useMemo(() => getEventsForCalendar(), [getEventsForCalendar]);
+
     const handleClosePopover = useCallback(() => {
         setAnchorEl(null);
     }, []);
@@ -74,9 +77,9 @@ export const ScheduleCalendar = memo(() => {
      * @returns A date with the earliest time or 7AM
      */
     const getStartTime = useCallback(() => {
-        const eventStartHours = getEventsForCalendar().map((event) => event.start.getHours());
+        const eventStartHours = events.map((event) => event.start.getHours());
         return new Date(2018, 0, 1, Math.min(7, Math.min(...eventStartHours)));
-    }, [getEventsForCalendar]);
+    }, [events]);
 
     const eventStyleGetter = useCallback((event: CalendarEvent) => {
         const style = {
@@ -113,7 +116,6 @@ export const ScheduleCalendar = memo(() => {
         return Math.abs(bgBrightness - textBrightness) > minBrightnessDiff;
     };
 
-    const events = useMemo(() => getEventsForCalendar(), [getEventsForCalendar]);
     const hasWeekendCourse = events.some((event) => event.start.getDay() === 0 || event.start.getDay() === 6);
 
     const calendarTimeFormat = isMilitaryTime ? 'HH:mm' : 'h:mm A';
@@ -124,8 +126,8 @@ export const ScheduleCalendar = memo(() => {
     const finalsDate = hoveredCalendarizedFinal
         ? getFinalsStartDateForTerm(hoveredCalendarizedFinal.term)
         : onlyCourseEvents.length > 0
-        ? getFinalsStartDateForTerm(onlyCourseEvents[0].term)
-        : getDefaultFinalsStartDate();
+          ? getFinalsStartDateForTerm(onlyCourseEvents[0].term)
+          : getDefaultFinalsStartDate();
 
     const finalsDateFormat = finalsDate ? 'ddd MM/DD' : 'ddd';
     const date = showFinalsSchedule && finalsDate ? finalsDate : new Date(2018, 0, 1);
diff --git a/apps/antalmanac/src/components/RightPane/SectionTable/CourseInfoButton.tsx b/apps/antalmanac/src/components/RightPane/SectionTable/CourseInfoButton.tsx
index a2372e3aa..0a9e2d9a2 100644
--- a/apps/antalmanac/src/components/RightPane/SectionTable/CourseInfoButton.tsx
+++ b/apps/antalmanac/src/components/RightPane/SectionTable/CourseInfoButton.tsx
@@ -72,11 +72,7 @@ function CourseInfoButton({
         isMobileScreen || (scheduleManagementWidth && scheduleManagementWidth < theme.breakpoints.values.xs);
 
     return (
-        <div
-            // onMouseEnter={handleMouseEnter}
-            // onMouseLeave={handleMouseLeave}
-            style={{ display: 'flex' }}
-        >
+        <div onMouseEnter={handleMouseEnter} onMouseLeave={handleMouseLeave} style={{ display: 'flex' }}>
             <Button
                 className={classes.button}
                 variant="contained"
diff --git a/apps/antalmanac/src/components/RightPane/SectionTable/SectionTableBody.tsx b/apps/antalmanac/src/components/RightPane/SectionTable/SectionTableBody.tsx
index 0c6fdab95..0b0b61928 100644
--- a/apps/antalmanac/src/components/RightPane/SectionTable/SectionTableBody.tsx
+++ b/apps/antalmanac/src/components/RightPane/SectionTable/SectionTableBody.tsx
@@ -499,7 +499,7 @@ const SectionTableBody = withStyles(styles)((props: SectionTableBodyProps) => {
     const isDark = useThemeStore((store) => store.isDark);
     const activeColumns = useColumnStore((store) => store.activeColumns);
     const previewMode = usePreviewStore((store) => store.previewMode);
-    const [hoveredEvent, setHoveredEvents] = useHoveredStore((store) => [store.hoveredEvent, store.setHoveredEvents]);
+    const setHoveredEvents = useHoveredStore((store) => store.setHoveredEvents);
 
     const [addedCourse, setAddedCourse] = useState(
         AppStore.getAddedSectionCodes().has(`${section.sectionCode} ${term}`)
@@ -528,17 +528,17 @@ const SectionTableBody = withStyles(styles)((props: SectionTableBodyProps) => {
         setCalendarEvents(AppStore.getCourseEventsInCalendar());
     }, [setCalendarEvents]);
 
-    const alreadyHovered = useMemo(() => {
-        return hoveredEvent?.section.sectionCode === section.sectionCode;
-    }, [hoveredEvent, section.sectionCode]);
-
-    const handleHover = useCallback(() => {
-        if (!previewMode || alreadyHovered || addedCourse) {
+    const handleMouseEnter = useCallback(() => {
+        if (!previewMode || addedCourse) {
             setHoveredEvents(undefined);
         } else {
             setHoveredEvents(section, courseDetails, term);
         }
-    }, [previewMode, alreadyHovered, addedCourse, setHoveredEvents, section, courseDetails, term]);
+    }, [previewMode, addedCourse, setHoveredEvents, section, courseDetails, term]);
+
+    const handleMouseLeave = useCallback(() => {
+        setHoveredEvents(undefined);
+    }, [setHoveredEvents]);
 
     // Attach event listeners to the store.
     useEffect(() => {
@@ -605,27 +605,37 @@ const SectionTableBody = withStyles(styles)((props: SectionTableBodyProps) => {
         return Boolean(conflictingEvent);
     }, [calendarEvents, sectionDetails]);
 
-    /* allowHighlight is always false on CourseRenderPane and always true on AddedCoursePane */
-    const computedAddedCourseStyle = allowHighlight
-        ? isDark
-            ? { background: '#b0b04f' }
-            : { background: '#fcfc97' }
-        : {};
-    const computedScheduleConflictStyle = scheduleConflict
-        ? isDark
-            ? { background: '#121212', opacity: '0.6' }
-            : { background: '#a0a0a0', opacity: '1' }
-        : {};
+    const computedRowStyle = useMemo(() => {
+        /* allowHighlight is always false on CourseRenderPane and always true on AddedCoursePane */
+        const computedAddedCourseStyle = allowHighlight
+            ? isDark
+                ? { background: '#b0b04f' }
+                : { background: '#fcfc97' }
+            : {};
+        const computedScheduleConflictStyle = scheduleConflict
+            ? isDark
+                ? { background: '#121212', opacity: '0.6' }
+                : { background: '#a0a0a0', opacity: '1' }
+            : {};
+
+        if (addedCourse) {
+            return computedAddedCourseStyle;
+        }
+
+        if (scheduleConflict) {
+            return computedScheduleConflictStyle;
+        }
 
-    const computedRowStyle = addedCourse ? computedAddedCourseStyle : computedScheduleConflictStyle;
+        return {};
+    }, [allowHighlight, isDark, scheduleConflict, addedCourse]);
 
     return (
         <TableRow
             classes={{ root: classes.row }}
             className={classNames(classes.tr)}
             style={computedRowStyle}
-            onMouseEnter={handleHover}
-            onMouseLeave={handleHover}
+            onMouseEnter={handleMouseEnter}
+            onMouseLeave={handleMouseLeave}
         >
             {Object.entries(tableBodyCells)
                 .filter(([column]) => activeColumns.includes(column as SectionTableColumn))
diff --git a/apps/antalmanac/src/stores/calendarizeHelpers.ts b/apps/antalmanac/src/stores/calendarizeHelpers.ts
index 12169c766..5f98f0213 100644
--- a/apps/antalmanac/src/stores/calendarizeHelpers.ts
+++ b/apps/antalmanac/src/stores/calendarizeHelpers.ts
@@ -19,9 +19,7 @@ export function getLocation(location: string): Location {
 }
 
 export const calendarizeCourseEvents = (currentCourses: ScheduleCourse[] = []): CourseEvent[] => {
-    console.log('hit', Date.now());
-
-    const foo = currentCourses.flatMap((course) => {
+    return currentCourses.flatMap((course) => {
         return course.section.meetings
             .filter((meeting) => !meeting.timeIsTBA)
             .flatMap((meeting) => {
@@ -82,10 +80,6 @@ export const calendarizeCourseEvents = (currentCourses: ScheduleCourse[] = []):
                 });
             });
     });
-
-    console.log(foo);
-
-    return foo;
 };
 
 export function calendarizeFinals(currentCourses: ScheduleCourse[] = []): CourseEvent[] {
@@ -124,8 +118,8 @@ export function calendarizeFinals(currentCourses: ScheduleCourse[] = []): Course
             const locationsWithNoDays = bldg
                 ? bldg.map(getLocation)
                 : !course.section.meetings[0].timeIsTBA
-                ? course.section.meetings[0].bldg.map(getLocation)
-                : [];
+                  ? course.section.meetings[0].bldg.map(getLocation)
+                  : [];
 
             /**
              * Fallback to January 2018 if no finals start date is available.