From 11fa0365f967c34f76ea5eb10ad95d57dd6f4f34 Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Sat, 31 Oct 2026 13:29:19 +0100
Subject: [PATCH] fix: clear the new event slot marker when the editor closes
 or the tab is left

---
 .../calendar/TimeGridScrollView.tsx           |  6 ++++++
 .../__tests__/slot-draft-reset.test.ts        | 21 +++++++++++++++++++
 src/screens/CalendarScreen.tsx                | 11 ++++++++++
 3 files changed, 38 insertions(+)
 create mode 100644 src/components/calendar/__tests__/slot-draft-reset.test.ts

diff --git a/src/components/calendar/TimeGridScrollView.tsx b/src/components/calendar/TimeGridScrollView.tsx
index 65f7503e..be6da07a 100644
--- a/src/components/calendar/TimeGridScrollView.tsx
+++ b/src/components/calendar/TimeGridScrollView.tsx
@@ -89,6 +89,8 @@ interface TimeGridScrollViewProps {
   onSelectDate?: (date: Date) => void;
   onSelectEvent?: (event: CalendarEvent) => void;
   onCreateAtTime?: (date: Date) => void;
+  /** A change takes the "New event" block away (the editor closed, the tab was left). */
+  draftResetKey?: number;
 }
 
 /**
@@ -119,6 +121,7 @@ function TimeGridScrollViewInner({
   onSelectDate,
   onSelectEvent,
   onCreateAtTime,
+  draftResetKey = 0,
 }: TimeGridScrollViewProps) {
   const c = useColors();
   // "Light event colors" (webmail calendarTintedEvents).
@@ -314,6 +317,9 @@ function TimeGridScrollViewInner({
   // A tap on an empty slot marks it with a "New event" block; tapping that
   // block creates the event. Two taps, so a stray tap never opens the editor.
   const [draft, setDraft] = React.useState<{ key: string; hour: number } | null>(null);
+  React.useEffect(() => {
+    setDraft(null);
+  }, [draftResetKey]);
   const handleTapAt = React.useCallback((day: Date, hour: number) => {
     const key = dayKey(day);
     setDraft((cur) => (cur && cur.key === key && cur.hour === hour ? null : { key, hour }));
diff --git a/src/components/calendar/__tests__/slot-draft-reset.test.ts b/src/components/calendar/__tests__/slot-draft-reset.test.ts
new file mode 100644
index 00000000..542e774d
--- /dev/null
+++ b/src/components/calendar/__tests__/slot-draft-reset.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it } from 'vitest';
+import fs from 'node:fs';
+import path from 'node:path';
+
+// Checked on the source: the suite has no React Native renderer.
+const grid = fs.readFileSync(path.resolve(__dirname, '../TimeGridScrollView.tsx'), 'utf8');
+const screen = fs.readFileSync(path.resolve(__dirname, '../../../screens/CalendarScreen.tsx'), 'utf8');
+
+describe('the "New event" block a tap on an empty slot leaves', () => {
+  it('goes when the grid is told to drop it', () => {
+    expect(grid).toMatch(/React\.useEffect\(\(\) => \{\s*setDraft\(null\);\s*\}, \[draftResetKey\]\);/);
+  });
+
+  it('is dropped when the editor opens or closes and when the user leaves the tab', () => {
+    const grids = screen.slice(screen.indexOf('<TimeGridScrollView'), screen.indexOf('/>', screen.indexOf('<TimeGridScrollView')));
+    expect(grids).toMatch(/draftResetKey=\{slotDraftReset\}/);
+    expect(screen).toMatch(/React\.useEffect\(\(\) => \{\s*setSlotDraftReset\(\(n\) => n \+ 1\);\s*\}, \[modalVisible\]\);/);
+    // The focus effect's cleanup runs on blur.
+    expect(screen).toMatch(/useFocusEffect\(\s*React\.useCallback\(\(\) => \(\) => setSlotDraftReset\(\(n\) => n \+ 1\), \[\]\),?\s*\)/);
+  });
+});
diff --git a/src/screens/CalendarScreen.tsx b/src/screens/CalendarScreen.tsx
index 38eb0432..3c36e138 100644
--- a/src/screens/CalendarScreen.tsx
+++ b/src/screens/CalendarScreen.tsx
@@ -11,6 +11,7 @@ import {
   useWindowDimensions,
 } from 'react-native';
 import { SafeAreaView } from 'react-native-safe-area-context';
+import { useFocusEffect } from '@react-navigation/native';
 import { TASK_CHIP_ID_PREFIX, multiDayCount } from '../lib/calendar-time-grid';
 import {
   Calendar as CalendarIcon,
@@ -239,6 +240,15 @@ export default function CalendarScreen() {
   const [modalEvent, setModalEvent] = React.useState<CalendarEvent | null>(null);
   const [modalDate, setModalDate] = React.useState<Date | undefined>(undefined);
   const [modalVisible, setModalVisible] = React.useState(false);
+  // The "New event" block a tap on an empty slot leaves: gone once the
+  // editor opens or closes, or the user leaves the tab.
+  const [slotDraftReset, setSlotDraftReset] = React.useState(0);
+  React.useEffect(() => {
+    setSlotDraftReset((n) => n + 1);
+  }, [modalVisible]);
+  useFocusEffect(
+    React.useCallback(() => () => setSlotDraftReset((n) => n + 1), []),
+  );
   const [pendingAction, setPendingAction] = React.useState<PendingAction>(null);
   const [sidebarVisible, setSidebarVisible] = React.useState(false);
   const [tasksVisible, setTasksVisible] = React.useState(false);
@@ -1177,6 +1187,7 @@ export default function CalendarScreen() {
             onSelectDate={viewMode === 'day' ? handleSelectDate : openDay}
             onSelectEvent={handleSelectEvent}
             onCreateAtTime={openCreate}
+            draftResetKey={slotDraftReset}
           />
         )}
         {viewMode === 'week' && !freeScroll && (