reactions: Add sheet to view who reacted to a message

Fixes zulip#740

assets/l10n/app_en.arb

@@ -104,6 +104,10 @@
   "@actionSheetOptionShare":  {
     "description": "Label for share button on action sheet."
   },
+  "actionSheetOptionViewReactions": "See who reacted",
+  "@actionSheetOptionViewReactions":  {
+    "description": "Label for View Reactions button on action sheet."
+  },
   "actionSheetOptionQuoteAndReply": "Quote and reply",
   "@actionSheetOptionQuoteAndReply":  {
     "description": "Label for Quote and reply button on action sheet."
@@ -116,6 +120,10 @@
   "@actionSheetOptionUnstarMessage":  {
     "description": "Label for unstar button on action sheet."
   },
+  "reactionSheetEmptyReactions": "No reactions yet",
+  "@reactionSheetEmptyReactions":  {
+    "description": "Text to display when the reactions sheet is open, but there are no reactions to show."
+  },
   "errorWebAuthOperationalErrorTitle": "Something went wrong",
   "@errorWebAuthOperationalErrorTitle": {
     "description": "Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials)."

lib/generated/l10n/zulip_localizations.dart

@@ -261,6 +261,12 @@ abstract class ZulipLocalizations {
   /// **'Share'**
   String get actionSheetOptionShare;
 
+  /// Label for View Reactions button on action sheet.
+  ///
+  /// In en, this message translates to:
+  /// **'See who reacted'**
+  String get actionSheetOptionViewReactions;
+
   /// Label for Quote and reply button on action sheet.
   ///
   /// In en, this message translates to:
@@ -279,6 +285,12 @@ abstract class ZulipLocalizations {
   /// **'Unstar message'**
   String get actionSheetOptionUnstarMessage;
 
+  /// Text to display when the reactions sheet is open, but there are no reactions to show.
+  ///
+  /// In en, this message translates to:
+  /// **'No reactions yet'**
+  String get reactionSheetEmptyReactions;
+
   /// Error title when third-party authentication has an operational error (not necessarily caused by invalid credentials).
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Share';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Quote and reply';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Share';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Quote and reply';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Share';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Quote and reply';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Share';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Quote and reply';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Unstar message';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Something went wrong';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Udostępnij';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Odpowiedz cytując';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Odbierz gwiazdkę';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Coś poszło nie tak';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Поделиться';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Ответить с цитированием';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Снять отметку с сообщения';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Что-то пошло не так';
 

lib/generated/l10n/zulip_localizations_sk.dart

@@ -88,6 +88,9 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   @override
   String get actionSheetOptionShare => 'Zdielať';
 
+  @override
+  String get actionSheetOptionViewReactions => 'See who reacted';
+
   @override
   String get actionSheetOptionQuoteAndReply => 'Citovať a odpovedať';
 
@@ -97,6 +100,9 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
   @override
   String get actionSheetOptionUnstarMessage => 'Odhviezdičkovať správu';
 
+  @override
+  String get reactionSheetEmptyReactions => 'No reactions yet';
+
   @override
   String get errorWebAuthOperationalErrorTitle => 'Niečo sa pokazilo';
 

lib/widgets/action_sheet.dart

@@ -392,6 +392,8 @@ void showMessageActionSheet({required BuildContext context, required Message mes
 
   final optionButtons = [
     ReactionButtons(message: message, pageContext: context),
+    if((message.reactions?.total ?? 0) > 0)
+      ViewReactionsButton(message: message, pageContext: context),
     StarButton(message: message, pageContext: context),
     if (isComposeBoxOffered)
       QuoteAndReplyButton(message: message, pageContext: context),
@@ -692,6 +694,25 @@ class QuoteAndReplyButton extends MessageActionSheetMenuItemButton {
   }
 }
 
+class ViewReactionsButton extends MessageActionSheetMenuItemButton {
+  ViewReactionsButton({super.key, required super.message, required super.pageContext});
+
+  @override IconData get icon => ZulipIcons.reactions;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionViewReactions;
+  }
+
+  @override void onPressed() async {
+    showReactionListSheet(
+      pageContext,
+      messageId: message.id,
+      messageListView: MessageListPage.ancestorOf(pageContext).model,
+    );
+  }
+}
+
 class MarkAsUnreadButton extends MessageActionSheetMenuItemButton {
   MarkAsUnreadButton({super.key, required super.message, required super.pageContext});