feat: show calendar events in light tinted colours on request

src/components/calendar/EventBlock.tsx

@@ -1,6 +1,6 @@
 import React from 'react';
 import { Pressable, StyleSheet, Text, View, type StyleProp, type ViewStyle } from 'react-native';
-import type { EventBlockColors } from '../../lib/event-colors';
+import { TINTED_BAR_WIDTH, type EventBlockColors } from '../../lib/event-colors';
 
 // Events in the week and day grids, shared by the paged WeekView and the
 // scrolling TimeGridScrollView. Every event is a solid block of its calendar
@@ -80,9 +80,11 @@ export function TimedEventBlock({
         styles.block,
         corners('vertical', continuesBefore, continuesAfter, EVENT_RADIUS),
         { backgroundColor: colors.fill, borderColor: ringColor },
+        colors.bar ? styles.blockWithBar : null,
         style,
       ]}
     >
+      {colors.bar ? <View pointerEvents="none" style={[styles.startBar, { backgroundColor: colors.bar }]} /> : null}
       {inactive && (
         // The calendar-coloured outline sits inside the ring.
         <View
@@ -143,10 +145,12 @@ export function AllDayEventBar({
         styles.bar,
         corners('horizontal', continuesBefore, continuesAfter, EVENT_RADIUS),
         { backgroundColor: colors.fill },
+        colors.bar ? styles.barWithBar : null,
         inactive && [styles.barInactive, { borderColor: colors.border ?? undefined }],
         style,
       ]}
     >
+      {colors.bar ? <View pointerEvents="none" style={[styles.startBar, { backgroundColor: colors.bar }]} /> : null}
       <Text style={[styles.barTitle, { color: colors.text }]} numberOfLines={1}>
         {continuesBefore ? '… ' : ''}
         <Text style={inactive && styles.struck}>{title}</Text>
@@ -164,6 +168,11 @@ const styles = StyleSheet.create({
     overflow: 'hidden',
   },
   outline: { ...StyleSheet.absoluteFillObject, borderWidth: 1 },
+  // The title clears the light style's bar.
+  blockWithBar: { paddingStart: 3 + TINTED_BAR_WIDTH },
+  barWithBar: { paddingStart: 4 + TINTED_BAR_WIDTH },
+  // "Light event colors": the calendar colour along the start edge.
+  startBar: { position: 'absolute', top: 0, bottom: 0, start: 0, width: TINTED_BAR_WIDTH },
   blockTitle: { fontSize: 12, lineHeight: 15, fontWeight: '500' },
   blockTime: { fontSize: 10.5, lineHeight: 13, fontWeight: '400', opacity: 0.85 },
   struck: { textDecorationLine: 'line-through' },

src/components/calendar/MonthView.tsx

@@ -14,6 +14,7 @@ import {
 import type { Calendar, CalendarEvent } from '../../api/types';
 import { componentSizes, spacing, typography, type ThemePalette } from '../../theme/tokens';
 import { useColors } from '../../theme/colors';
+import { useSettingsStore } from '../../stores/settings-store';
 import {
   buildEventDayIndex,
   eventsOnDayFromIndex,
@@ -26,7 +27,7 @@ import {
 } from '../../lib/calendar-utils';
 import { dayIndexIn, monthChipShowsTime, monthKeyOf, monthMask } from '../../lib/calendar-month-scroll';
 import { isInactiveEvent } from '../../lib/calendar-participants';
-import { eventBlockColors } from '../../lib/event-colors';
+import { TINTED_BAR_WIDTH, eventBlockColors } from '../../lib/event-colors';
 import { useCalendarLocale } from '../../lib/calendar-locale';
 import { dayCellAccessibilityLabel } from '../../lib/calendar-a11y';
 import { displayNow } from '../../lib/calendar-timezone';
@@ -156,6 +157,8 @@ function MonthWeekRowInner({
   const c = useColors();
   const { t } = useCalendarLocale();
   const { width } = useWindowDimensions();
+  // "Light event colors" (webmail calendarTintedEvents).
+  const tinted = useSettingsStore((s) => s.calendarTintedEvents);
   const chipTime = monthChipShowsTime(true, width / 7);
   if (variant === 'full') {
     return (
@@ -254,13 +257,14 @@ function MonthWeekRowInner({
                   // Solid bars in the calendar colour; declined and
                   // cancelled events outlined (repos/branding/APP.md).
                   const inactive = isInactiveEvent(event, currentUserEmails);
-                  const colors = eventBlockColors(getEventColor(event, calendars), inactive, c);
+                  const colors = eventBlockColors(getEventColor(event, calendars), inactive, c, tinted);
                   return (
                     <View
                       key={`${event.id}-${idx}`}
                       style={[
                         styles.chip,
                         { backgroundColor: colors.fill },
+                        colors.bar ? { borderStartWidth: TINTED_BAR_WIDTH, borderStartColor: colors.bar } : null,
                         colors.border !== null && [styles.chipInactive, { borderColor: colors.border }],
                       ]}
                     >
@@ -327,6 +331,8 @@ function FullWeekRow({
 }) {
   const { width } = useWindowDimensions();
   const { t } = useCalendarLocale();
+  // "Light event colors" (webmail calendarTintedEvents).
+  const tinted = useSettingsStore((s) => s.calendarTintedEvents);
   const showTime = monthChipShowsTime(showTimeInMonthView, width / 7);
   return (
     <View style={[styles.fullWeekRow, { height }]}>
@@ -365,7 +371,7 @@ function FullWeekRow({
             </View>
             {dayEvents.slice(0, shown).map((event, idx) => {
               const inactive = isInactiveEvent(event, currentUserEmails);
-              const colors = eventBlockColors(getEventColor(event, calendars), inactive, c);
+              const colors = eventBlockColors(getEventColor(event, calendars), inactive, c, tinted);
               // No time on events that fill the whole day.
               const time = showTime && !event.showWithoutTime && !isTimedEventFullDayOnDate(event, d)
                 ? `${format(getEventStartDate(event), timePattern(timeFormat), { locale })} `
@@ -376,6 +382,7 @@ function FullWeekRow({
                   style={[
                     styles.fullChip,
                     { backgroundColor: colors.fill },
+                    colors.bar ? { borderStartWidth: TINTED_BAR_WIDTH, borderStartColor: colors.bar } : null,
                     colors.border !== null && [styles.chipInactive, { borderColor: colors.border }],
                   ]}
                 >

src/components/calendar/TimeGridScrollView.tsx

@@ -19,6 +19,7 @@ import { differenceInCalendarDays, format, type Locale } from 'date-fns';
 import type { Calendar, CalendarEvent } from '../../api/types';
 import { spacing, typography, type ThemePalette } from '../../theme/tokens';
 import { useColors } from '../../theme/colors';
+import { useSettingsStore } from '../../stores/settings-store';
 import { useCalendarLocale } from '../../lib/calendar-locale';
 import { eventAccessibilityLabel } from '../../lib/calendar-a11y';
 import {
@@ -120,6 +121,8 @@ function TimeGridScrollViewInner({
   onCreateAtTime,
 }: TimeGridScrollViewProps) {
   const c = useColors();
+  // "Light event colors" (webmail calendarTintedEvents).
+  const tinted = useSettingsStore((s) => s.calendarTintedEvents);
   const styles = React.useMemo(() => makeStyles(c), [c]);
   const { locale, t } = useCalendarLocale();
   const index = React.useMemo(
@@ -448,6 +451,7 @@ function TimeGridScrollViewInner({
                   getEventColor(segment.event, calendars),
                   isInactiveEvent(segment.event, currentUserEmails),
                   c,
+                  tinted,
                 )}
                 continuesBefore={segment.continuesBefore}
                 continuesAfter={segment.continuesAfter}
@@ -606,6 +610,8 @@ const DayColumn = React.memo(function DayColumn({
   draftHour: number;
 }) {
   const { locale, t } = useCalendarLocale();
+  // "Light event colors" (webmail calendarTintedEvents).
+  const tinted = useSettingsStore((s) => s.calendarTintedEvents);
   const handleLongPress = React.useCallback(
     (e: GestureResponderEvent) => {
       onLongPressAt?.(day, hourAtOffset(e.nativeEvent.locationY, HOUR_HEIGHT));
@@ -639,6 +645,7 @@ const DayColumn = React.memo(function DayColumn({
               getEventColor(event, calendars),
               isInactiveEvent(event, currentUserEmails),
               colors,
+                  tinted,
             )}
             ringColor={colors.background}
             continuesBefore={continuesBefore}

src/components/calendar/WeekView.tsx

@@ -11,6 +11,7 @@ import { displayNow, displayNowMinutes, isDisplayToday } from '../../lib/calenda
 import type { Calendar, CalendarEvent } from '../../api/types';
 import { spacing, typography, type ThemePalette } from '../../theme/tokens';
 import { useColors } from '../../theme/colors';
+import { useSettingsStore } from '../../stores/settings-store';
 import { useCalendarLocale } from '../../lib/calendar-locale';
 import { eventAccessibilityLabel } from '../../lib/calendar-a11y';
 import {
@@ -66,6 +67,8 @@ function WeekViewInner({
   currentUserEmails,
 }: WeekViewProps) {
   const c = useColors();
+  // "Light event colors" (webmail calendarTintedEvents).
+  const tinted = useSettingsStore((s) => s.calendarTintedEvents);
   const styles = React.useMemo(() => makeStyles(c), [c]);
   const { locale, t } = useCalendarLocale();
   const scrollRef = React.useRef<ScrollView>(null);
@@ -212,6 +215,7 @@ function WeekViewInner({
                       getEventColor(segment.event, calendars),
                       isInactiveEvent(segment.event, currentUserEmails),
                       c,
+                      tinted,
                     )}
                     continuesBefore={segment.continuesBefore}
                     continuesAfter={segment.continuesAfter}
@@ -287,6 +291,7 @@ function WeekViewInner({
                             getEventColor(event, calendars),
                             isInactiveEvent(event, currentUserEmails),
                             c,
+                      tinted,
                           )}
                           ringColor={c.background}
                           continuesBefore={continuesBefore}

src/components/settings/CalendarSettings.tsx

@@ -44,6 +44,7 @@ export function CalendarSettings() {
   const timeZone = useSettingsStore((s) => s.calendarTimeZone);
   const showTimeInMonth = useSettingsStore((s) => s.calendarShowTimeInMonth);
   const showWeekNumbers = useSettingsStore((s) => s.calendarShowWeekNumbers);
+  const tintedEvents = useSettingsStore((s) => s.calendarTintedEvents);
   const freeScroll = useSettingsStore((s) => s.calendarFreeScroll);
   const birthdayCal = useSettingsStore((s) => s.showBirthdayCalendar);
   const tasksEnabled = useSettingsStore((s) => s.enableCalendarTasks);
@@ -135,6 +136,19 @@ export function CalendarSettings() {
           />
         </SettingItem>
 
+        <SettingItem
+          label={t('calendar.settings.tinted_events', 'Light event colors')}
+          description={t(
+            'calendar.settings.tinted_events_desc',
+            'Show events as a light tint of their calendar color with a colored bar at the start, as in Outlook and on printouts, instead of solid blocks.',
+          )}
+        >
+          <ToggleSwitch
+            checked={tintedEvents}
+            onChange={(v) => update('calendarTintedEvents', v)}
+          />
+        </SettingItem>
+
         <SettingItem
           label={t('calendar.settings.show_week_numbers', 'Show week numbers')}
           description={t('calendar.settings.show_week_numbers_mobile_desc', 'Display week numbers in the month view.')}

src/lib/__tests__/calendar-tinted-events.test.ts

@@ -0,0 +1,51 @@
+import { describe, it, expect } from 'vitest';
+import fs from 'node:fs';
+import path from 'node:path';
+import { eventBlockColors, mixColors } from '../event-colors';
+import { mergeWithDefaults } from '../../stores/settings-store';
+
+// The webmail's "Light event colors" (calendarTintedEvents) had no
+// counterpart on the phone (file 10 "light tinted colours"). Webmail
+// event-card eventFillStyle: color-mix(color 20%, background), foreground
+// text, a calendar-coloured bar at the start.
+
+const page = { background: '#ffffff', text: '#111111' };
+const read = (rel: string) => fs.readFileSync(path.resolve(__dirname, '../..', rel), 'utf8');
+
+describe('light event colours', () => {
+  it('tints active events and adds the start bar', () => {
+    expect(eventBlockColors('#3b82f6', false, page, true)).toEqual({
+      fill: mixColors('#3b82f6', '#ffffff', 0.2),
+      text: '#111111',
+      border: null,
+      bar: '#3b82f6',
+    });
+    expect(mixColors('#3b82f6', '#ffffff', 0.2)).toBe('#d8e6fd');
+    // Solid blocks stay the default.
+    expect(eventBlockColors('#3b82f6', false, page)).toMatchObject({ fill: '#3b82f6' });
+    expect(eventBlockColors('#3b82f6', false, page).bar).toBeUndefined();
+  });
+
+  it('keeps declined and cancelled events outlined', () => {
+    const colors = eventBlockColors('#3b82f6', true, page, true);
+    expect(colors.border).toBe('#3b82f6');
+    expect(colors.fill).toBe('#ffffff');
+    expect(colors.bar).toBeUndefined();
+  });
+
+  it('is a setting, off by default, under the webmail key', () => {
+    expect(mergeWithDefaults({}).calendarTintedEvents).toBe(false);
+    expect(mergeWithDefaults({ calendarTintedEvents: true }).calendarTintedEvents).toBe(true);
+  });
+
+  // No RN renderer in the test env: check the wiring.
+  it('is offered in the calendar settings and read by every grid', () => {
+    expect(read('components/settings/CalendarSettings.tsx')).toMatch(/onChange=\{\(v\) => update\('calendarTintedEvents', v\)\}/);
+    for (const view of ['MonthView', 'TimeGridScrollView', 'WeekView']) {
+      const src = read(`components/calendar/${view}.tsx`);
+      expect(src).toMatch(/const tinted = useSettingsStore\(\(s\) => s\.calendarTintedEvents\);/);
+      expect(src).toMatch(/eventBlockColors\([\s\S]*?tinted,?\s*\)/);
+    }
+    expect(read('components/calendar/EventBlock.tsx').match(/colors\.bar \? <View pointerEvents="none" style=\{\[styles\.startBar/g)).toHaveLength(2);
+  });
+});

src/lib/event-colors.ts

@@ -149,17 +149,28 @@ export interface EventBlockColors {
   text: string;
   /** Inset border in the calendar colour, for declined and cancelled events only. */
   border: string | null;
+  /** The light style's bar along the start edge, in the calendar colour; null without it. */
+  bar?: string | null;
 }
 
+/** Share of the calendar colour in the light style's fill (webmail color-mix 20%). */
+export const TINTED_FILL_MIX = 0.2;
+/** Width of the light style's bar (webmail --start-bar-width). */
+export const TINTED_BAR_WIDTH = 3;
+
 /**
  * Fill, label and border of an event block, bar or chip. Active events are
- * solid calendar colour with a computed label colour; declined and cancelled
- * ones sit on the page ground inside a calendar-coloured border.
+ * solid calendar colour with a computed label colour, or with "Light event
+ * colors" (`tinted`) a 20% tint of it on the page ground with the text
+ * colour and a calendar-coloured bar at the start (webmail eventFillStyle);
+ * declined and cancelled ones sit on the page ground inside a
+ * calendar-coloured border either way.
  */
 export function eventBlockColors(
   calendarColor: string,
   inactive: boolean,
   page: { background: string; text: string },
+  tinted = false,
 ): EventBlockColors {
   if (inactive) {
     return {
@@ -168,5 +179,9 @@ export function eventBlockColors(
       border: calendarColor,
     };
   }
+  if (tinted) {
+    const fill = mixColors(calendarColor, page.background, TINTED_FILL_MIX);
+    if (fill) return { fill, text: page.text, border: null, bar: calendarColor };
+  }
   return { fill: calendarColor, text: readableTextOn(calendarColor), border: null };
 }

src/stores/settings-store.ts

@@ -325,6 +325,10 @@ export interface PersistedSettings {
   // reader: the quick reply box under a conversation can be turned off
   // (webmail #1370, same key as the webmail's for export/import).
   quickReplyEnabled: boolean;
+  // calendar2: events as a light tint of their calendar colour with a
+  // coloured bar at the start, instead of solid blocks (webmail
+  // calendarTintedEvents, same key).
+  calendarTintedEvents: boolean;
 }
 
 const DEFAULT_PERSISTED: PersistedSettings = {
@@ -487,6 +491,8 @@ const DEFAULT_PERSISTED: PersistedSettings = {
   pushNotifyInboxOnly: false,
   // reader:
   quickReplyEnabled: true,
+  // calendar2:
+  calendarTintedEvents: false,
 };
 
 export interface SettingsState extends PersistedSettings {