action_sheet: Add channel action sheet with mark as read option

Fixes: zulip#1226

assets/l10n/app_en.arb

@@ -76,6 +76,10 @@
   "@permissionsDeniedReadExternalStorage": {
     "description": "Message for dialog asking the user to grant permissions for external storage read access."
   },
+  "actionSheetOptionMarkChannelAsRead": "Mark channel as read",
+  "@actionSheetOptionMarkChannelAsRead": {
+    "description": "Label for marking a channel as read."
+  },
   "actionSheetOptionMuteTopic": "Mute topic",
   "@actionSheetOptionMuteTopic":  {
     "description": "Label for muting a topic on action sheet."

lib/generated/l10n/zulip_localizations.dart

@@ -219,6 +219,12 @@ abstract class ZulipLocalizations {
   /// **'To upload files, please grant Zulip additional permissions in Settings.'**
   String get permissionsDeniedReadExternalStorage;
 
+  /// Label for marking a channel as read.
+  ///
+  /// In en, this message translates to:
+  /// **'Mark channel as read'**
+  String get actionSheetOptionMarkChannelAsRead;
+
   /// Label for muting a topic on action sheet.
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'To upload files, please grant Zulip additional permissions in Settings.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Mute topic';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'To upload files, please grant Zulip additional permissions in Settings.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Mute topic';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'To upload files, please grant Zulip additional permissions in Settings.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Mute topic';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'To upload files, please grant Zulip additional permissions in Settings.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Mute topic';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'Aby odebrać pliki Zulip musi uzyskać dodatkowe uprawnienia w Ustawieniach.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Wycisz wątek';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'Для загрузки файлов, пожалуйста, предоставьте Zulip дополнительные разрешения в настройках.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Отключить тему';
 

lib/generated/l10n/zulip_localizations_sk.dart

@@ -67,6 +67,9 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   @override
   String get permissionsDeniedReadExternalStorage => 'To upload files, please grant Zulip additional permissions in Settings.';
 
+  @override
+  String get actionSheetOptionMarkChannelAsRead => 'Mark channel as read';
+
   @override
   String get actionSheetOptionMuteTopic => 'Stlmiť tému';
 

lib/widgets/action_sheet.dart

@@ -163,6 +163,55 @@ class ActionSheetCancelButton extends StatelessWidget {
   }
 }
 
+/// Show a sheet of actions you can take on a channel.
+void showChannelActionSheet(BuildContext context, {
+  required int channelId,
+}) {
+  final pageContext = PageRoot.contextOf(context);
+  final store = PerAccountStoreWidget.of(pageContext);
+
+  final optionButtons = <ActionSheetMenuItemButton>[];
+  final unreadCount = store.unreads.countInChannelNarrow(channelId);
+  if (unreadCount > 0) {
+    optionButtons.add(
+      MarkChannelAsReadButton(pageContext: pageContext,streamId: channelId));
+  }
+  if (optionButtons.isEmpty) {
+    // TODO(a11y): This case makes a no-op gesture handler; as a consequence,
+    //   we're presenting some UI (to people who use screen-reader software) as
+    //   though it offers a gesture interaction that it doesn't meaningfully
+    //   offer, which is confusing. The solution here is probably to remove this
+    //   is-empty case by having at least one button that's always present,
+    //   such as "copy link to channel".
+    return;
+  }
+  _showActionSheet(pageContext, optionButtons: optionButtons);
+}
+
+class MarkChannelAsReadButton extends ActionSheetMenuItemButton {
+  const MarkChannelAsReadButton({
+    super.key,
+    required this.streamId,
+    required super.pageContext
+  });
+
+  final int streamId;
+
+  @override
+  IconData get icon => ZulipIcons.message_checked;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionMarkChannelAsRead;
+  }
+
+  @override
+  void onPressed() async {
+    final narrow = ChannelNarrow(streamId);
+    await ZulipAction.markNarrowAsRead(pageContext, narrow);
+  }
+}
+
 /// Show a sheet of actions you can take on a topic.
 ///
 /// Needs a [PageRoot] ancestor.

lib/widgets/inbox.dart

@@ -272,6 +272,9 @@ abstract class _HeaderItem extends StatelessWidget {
         //   But that's in tension with the Figma, which gives these header rows
         //   40px min height.
         onTap: onCollapseButtonTap,
+        onLongPress: this is _LongPressable
+          ? (this as _LongPressable).onLongPress
+          : null,
         child: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
           Padding(padding: const EdgeInsets.all(10),
             child: Icon(size: 20, color: designVariables.sectionCollapseIcon,
@@ -431,7 +434,13 @@ class _DmItem extends StatelessWidget {
   }
 }
 
-class _StreamHeaderItem extends _HeaderItem {
+mixin _LongPressable on _HeaderItem {
+  // TODO(#1272) move to _HeaderItem base class
+  //   when DM headers become long-pressable; remove mixin
+  Future<void> onLongPress();
+}
+
+class _StreamHeaderItem extends _HeaderItem with _LongPressable {
   final Subscription subscription;
 
   const _StreamHeaderItem({
@@ -464,6 +473,11 @@ class _StreamHeaderItem extends _HeaderItem {
     }
   }
   @override Future<void> onRowTap() => onCollapseButtonTap(); // TODO open channel narrow
+
+  @override
+  Future<void> onLongPress() async {
+    showChannelActionSheet(sectionContext, channelId: subscription.streamId);
+  }
 }
 
 class _StreamSection extends StatelessWidget {

lib/widgets/message_list.dart

@@ -395,36 +395,47 @@ class MessageListAppBarTitle extends StatelessWidget {
       case ChannelNarrow(:var streamId):
         final store = PerAccountStoreWidget.of(context);
         final stream = store.streams[streamId];
-        return _buildStreamRow(context, stream: stream);
+        return GestureDetector(
+          behavior: HitTestBehavior.translucent,
+          onLongPress: () {
+            showChannelActionSheet(context, channelId: streamId);
+          },
+          child: _buildStreamRow(context, stream: stream));
 
       case TopicNarrow(:var streamId, :var topic):
         final store = PerAccountStoreWidget.of(context);
         final stream = store.streams[streamId];
-        return SizedBox(
-          width: double.infinity,
-          child: GestureDetector(
-            behavior: HitTestBehavior.translucent,
-            onLongPress: () {
-              final someMessage = MessageListPage.ancestorOf(context)
-                .model?.messages.firstOrNull;
-              // If someMessage is null, the topic action sheet won't have a
-              // resolve/unresolve button. That seems OK; in that case we're
-              // either still fetching messages (and the user can reopen the
-              // sheet after that finishes) or there aren't any messages to
-              // act on anyway.
-              assert(someMessage == null || narrow.containsMessage(someMessage));
-              showTopicActionSheet(context,
-                channelId: streamId,
-                topic: topic,
-                someMessageIdInTopic: someMessage?.id);
-            },
-            child: Column(
-              crossAxisAlignment: willCenterTitle ? CrossAxisAlignment.center
-                                                  : CrossAxisAlignment.start,
-              children: [
-                _buildStreamRow(context, stream: stream),
-                _buildTopicRow(context, stream: stream, topic: topic),
-              ])));
+        final alignment = willCenterTitle
+          ? Alignment.center
+          : AlignmentDirectional.centerStart;
+        return Column(
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            GestureDetector(
+              behavior: HitTestBehavior.translucent,
+              onLongPress: () {
+                showChannelActionSheet(context, channelId: streamId);
+              },
+              child: Align(alignment: alignment,
+                child: _buildStreamRow(context, stream: stream))),
+            GestureDetector(
+              behavior: HitTestBehavior.translucent,
+              onLongPress: () {
+                final someMessage = MessageListPage.ancestorOf(context)
+                  .model?.messages.firstOrNull;
+                // If someMessage is null, the topic action sheet won't have a
+                // resolve/unresolve button. That seems OK; in that case we're
+                // either still fetching messages (and the user can reopen the
+                // sheet after that finishes) or there aren't any messages to
+                // act on anyway.
+                assert(someMessage == null || narrow.containsMessage(someMessage));
+                showTopicActionSheet(context,
+                  channelId: streamId,
+                  topic: topic,
+                  someMessageIdInTopic: someMessage?.id);
+              },
+              child: Align(alignment: alignment,
+                child: _buildTopicRow(context, stream: stream, topic: topic)))]);
 
       case DmNarrow(:var otherRecipientIds):
         final store = PerAccountStoreWidget.of(context);
@@ -1083,6 +1094,7 @@ class StreamMessageRecipientHeader extends StatelessWidget {
         onTap: () => Navigator.push(context,
           MessageListPage.buildRoute(context: context,
             narrow: ChannelNarrow(message.streamId))),
+        onLongPress: () => showChannelActionSheet(context, channelId: message.streamId),
         child: Row(
           crossAxisAlignment: CrossAxisAlignment.center,
           children: [

lib/widgets/subscription_list.dart

@@ -4,6 +4,7 @@ import '../api/model/model.dart';
 import '../generated/l10n/zulip_localizations.dart';
 import '../model/narrow.dart';
 import '../model/unreads.dart';
+import 'action_sheet.dart';
 import 'icons.dart';
 import 'message_list.dart';
 import 'store.dart';
@@ -230,6 +231,7 @@ class SubscriptionItem extends StatelessWidget {
             MessageListPage.buildRoute(context: context,
               narrow: ChannelNarrow(subscription.streamId)));
         },
+        onLongPress: () => showChannelActionSheet(context, channelId: subscription.streamId),
         child: Row(crossAxisAlignment: CrossAxisAlignment.center, children: [
           const SizedBox(width: 16),
           Padding(