mobile: share and test the page typing selector

Channel and thread pages now watch one visibleTypingProvider, and a test
checks that the user's own echoed indicator does not notify it while
another user's typing does.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Tom Brow <tomb@block.xyz>

mobile/lib/features/channels/channel_detail_page.dart

@@ -366,12 +366,10 @@ class _ResolvedChannelDetailPage extends HookConsumerWidget {
     // Ordinary channels keep thread activity inside the thread view.
     final typingEntries = ref
         .watch(
-          channelTypingProvider(channel.id).select(
+          visibleTypingProvider(
-            (all) => VisibleTyping(
+            channel.id,
-              all,
+            selfPubkey: currentPubkey,
-              selfPubkey: currentPubkey,
+            include: (e) => personalChat || e.threadHeadId == null,
-              include: (e) => personalChat || e.threadHeadId == null,
-            ),
           ),
         )
         .entries;

mobile/lib/features/channels/channel_typing_provider.dart

@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:flutter/foundation.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:hooks_riverpod/misc.dart' show ProviderListenable;
 
 import '../../shared/relay/relay.dart';
 
@@ -56,6 +57,17 @@ class VisibleTyping {
   int get hashCode => Object.hashAll(entries);
 }
 
+/// What a page watches to show typing in [channelId]: everyone but
+/// [selfPubkey], filtered by [include]. The user's own echoed indicator
+/// refreshes its expiry every few seconds, and this skips those updates.
+ProviderListenable<VisibleTyping> visibleTypingProvider(
+  String channelId, {
+  required String? selfPubkey,
+  required bool Function(TypingEntry entry) include,
+}) => channelTypingProvider(
+  channelId,
+).select((all) => VisibleTyping(all, selfPubkey: selfPubkey, include: include));
+
 /// Tracks who is currently typing in a specific channel.
 ///
 /// Subscribes to typing and message events so a reply ends its typing signal.

mobile/lib/features/channels/thread_detail_page.dart

@@ -786,12 +786,10 @@ class ThreadDetailPage extends HookConsumerWidget {
     // Thread-scoped typing indicators (exclude self).
     final threadTyping = ref
         .watch(
-          channelTypingProvider(channelId).select(
+          visibleTypingProvider(
-            (all) => VisibleTyping(
+            channelId,
-              all,
+            selfPubkey: currentPubkey,
-              selfPubkey: currentPubkey,
+            include: (e) => e.threadHeadId == threadHead.id,
-              include: (e) => e.threadHeadId == threadHead.id,
-            ),
           ),
         )
         .entries;

mobile/test/features/channels/channel_typing_provider_test.dart

@@ -247,4 +247,47 @@ void main() {
       container.dispose();
     }),
   );
+  test(
+    'pages ignore the user\'s own typing echo but see others',
+    () => fakeAsync((async) {
+      final relay = _Relay();
+      final container = ProviderContainer(
+        overrides: [relaySessionProvider.overrideWith(() => relay)],
+      );
+      final seen = <List<String>>[];
+      container.listen(
+        visibleTypingProvider(
+          'chat',
+          selfPubkey: 'ME',
+          include: (e) => e.threadHeadId == null,
+        ),
+        (_, next) => seen.add([for (final e in next.entries) e.pubkey]),
+      );
+      _settle(container, async);
+      void typing(String id, String pubkey) => relay.receive(
+        NostrEvent(
+          id: id,
+          pubkey: pubkey,
+          kind: 20002,
+          createdAt: DateTime.now().millisecondsSinceEpoch ~/ 1000,
+          content: '',
+          sig: '',
+          tags: [
+            ['h', 'chat'],
+          ],
+        ),
+      );
+      for (var i = 0; i < 3; i++) {
+        typing('self-$i', 'me');
+        async.elapse(const Duration(seconds: 3));
+      }
+      expect(container.read(channelTypingProvider('chat')), hasLength(1));
+      expect(seen, isEmpty);
+      typing('other', 'agent');
+      expect(seen, [
+        ['agent'],
+      ]);
+      container.dispose();
+    }),
+  );
 }