Typing while the emoji picker is up should enter search mode

ts/components/conversation/ReactionPicker.tsx

@@ -54,7 +54,7 @@ export const ReactionPicker = React.forwardRef<HTMLDivElement, Props>(
     // Handle escape key
     React.useEffect(() => {
       const handler = (e: KeyboardEvent) => {
-        if (onClose && e.key === 'Escape') {
+        if (onClose && e.key === 'Escape' && !pickingOther) {
           onClose();
         }
       };
@@ -64,7 +64,7 @@ export const ReactionPicker = React.forwardRef<HTMLDivElement, Props>(
       return () => {
         document.removeEventListener('keydown', handler);
       };
-    }, [onClose]);
+    }, [onClose, pickingOther]);
 
     // Handle EmojiPicker::onPickEmoji
     const onPickEmoji: EmojiPickerProps['onPickEmoji'] = React.useCallback(

ts/components/emoji/EmojiPicker.tsx

@@ -23,6 +23,7 @@ import FocusTrap from 'focus-trap-react';
 import { Emoji } from './Emoji';
 import { dataByCategory, search } from './lib';
 import type { LocalizerType } from '../../types/Util';
+import { isSingleGrapheme } from '../../util/grapheme';
 
 export type EmojiPickDataType = {
   skinTone?: number;
@@ -152,35 +153,45 @@ export const EmojiPicker = React.memo(
         [doSend, onPickEmoji, selectedTone]
       );
 
-      // Handle escape key
+      // Handle key presses, particularly Escape
       React.useEffect(() => {
         const handler = (event: KeyboardEvent) => {
-          if (searchMode && event.key === 'Escape') {
-            setScrollToRow(0);
-            setSearchText('');
-            setSearchMode(false);
-
-            event.preventDefault();
-            event.stopPropagation();
-          } else if (
-            !searchMode &&
-            !event.ctrlKey &&
-            ![
-              'ArrowUp',
-              'ArrowDown',
-              'ArrowLeft',
-              'ArrowRight',
-              'Shift',
-              'Tab',
-              ' ', // Space
-            ].includes(event.key)
-          ) {
-            if (onClose) {
-              onClose();
+          if (event.key === 'Escape') {
+            if (searchMode) {
+              setScrollToRow(0);
+              setSearchText('');
+              setSearchMode(false);
+            } else {
+              onClose?.();
             }
-
             event.preventDefault();
             event.stopPropagation();
+          } else if (!searchMode && !event.ctrlKey && !event.metaKey) {
+            if (
+              [
+                'ArrowUp',
+                'ArrowDown',
+                'ArrowLeft',
+                'ArrowRight',
+                'Enter',
+                'Shift',
+                'Tab',
+                ' ', // Space
+              ].includes(event.key)
+            ) {
+              // Do nothing, these can be used to navigate around the picker.
+            } else if (isSingleGrapheme(event.key)) {
+              // A single grapheme means the user is typing text. Switch to search mode.
+              setSelectedCategory(categories[0]);
+              setSearchMode(true);
+              // Continue propagation, typing the first letter for search.
+            } else {
+              // For anything else, assume it's a special key that isn't one of the ones
+              // above (such as Delete or ContextMenu).
+              onClose?.();
+              event.preventDefault();
+              event.stopPropagation();
+            }
           }
         };
 
@@ -189,7 +200,7 @@ export const EmojiPicker = React.memo(
         return () => {
           document.removeEventListener('keydown', handler);
         };
-      }, [onClose, searchMode]);
+      }, [onClose, searchMode, setSearchMode]);
 
       const [, ...renderableCategories] = categories;
 

ts/test-both/util/grapheme_test.ts

@@ -1,9 +1,9 @@
-// Copyright 2021 Signal Messenger, LLC
+// Copyright 2021-2022 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { assert } from 'chai';
 
-import { getGraphemes, count } from '../../util/grapheme';
+import { getGraphemes, count, isSingleGrapheme } from '../../util/grapheme';
 
 describe('grapheme utilities', () => {
   describe('getGraphemes', () => {
@@ -63,4 +63,20 @@ describe('grapheme utilities', () => {
       assert.strictEqual(count('L̷̳͔̲͝Ģ̵̮̯̤̩̙͍̬̟͉̹̘̹͍͈̮̦̰̣͟͝O̶̴̮̻̮̗͘͡!̴̷̟͓͓'), 4);
     });
   });
+
+  describe('isSingleGrapheme', () => {
+    it('returns false for the empty string', () => {
+      assert.isFalse(isSingleGrapheme(''));
+    });
+    it('returns true for single graphemes', () => {
+      assert.isTrue(isSingleGrapheme('a'));
+      assert.isTrue(isSingleGrapheme('å'));
+      assert.isTrue(isSingleGrapheme('😍'));
+    });
+    it('returns false for multiple graphemes', () => {
+      assert.isFalse(isSingleGrapheme('ab'));
+      assert.isFalse(isSingleGrapheme('a😍'));
+      assert.isFalse(isSingleGrapheme('😍a'));
+    });
+  });
 });

ts/util/grapheme.ts

@@ -1,4 +1,4 @@
-// Copyright 2021 Signal Messenger, LLC
+// Copyright 2021-2022 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { map, size } from './iterables';
@@ -12,3 +12,11 @@ export function count(str: string): number {
   const segments = new Intl.Segmenter().segment(str);
   return size(segments);
 }
+
+export function isSingleGrapheme(str: string): boolean {
+  if (str === '') {
+    return false;
+  }
+  const segments = new Intl.Segmenter().segment(str);
+  return segments.containing(0).segment === str;
+}