compose: Support editing an already-sent message

lakshya1goel · lakshya1goel · commit 7902e3e961ca · 2025-01-30T20:37:12.000+05:30
Fixes: #126
diff --git a/assets/l10n/app_en.arb b/assets/l10n/app_en.arb
@@ -680,5 +680,17 @@
   "emojiPickerSearchEmoji": "Search emoji",
   "@emojiPickerSearchEmoji": {
     "description": "Hint text for the emoji picker search text field."
+  },
+  "actionSheetOptionEditMessage": "Edit",
+  "@actionSheetOptionEditMessage": {
+    "description": "Label for action sheet button to edit a message."
+  },
+  "errorEditingFailed": "Failed to edit message",
+  "@errorEditingFailed": {
+    "description": "Error title when editing a message fails."
+  },
+  "editMessageSaveTooltip": "Save changes",
+  "@editMessageSaveTooltip": {
+    "description": "Tooltip for the save button when editing a message"
   }
 }
diff --git a/lib/generated/l10n/zulip_localizations.dart b/lib/generated/l10n/zulip_localizations.dart
@@ -1016,6 +1016,24 @@ abstract class ZulipLocalizations {
   /// In en, this message translates to:
   /// **'Search emoji'**
   String get emojiPickerSearchEmoji;
+
+  /// Label for action sheet button to edit a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Edit'**
+  String get actionSheetOptionEditMessage;
+
+  /// Error title when editing a message fails.
+  ///
+  /// In en, this message translates to:
+  /// **'Failed to edit message'**
+  String get errorEditingFailed;
+
+  /// Tooltip for the save button when editing a message
+  ///
+  /// In en, this message translates to:
+  /// **'Save changes'**
+  String get editMessageSaveTooltip;
 }
 
 class _ZulipLocalizationsDelegate extends LocalizationsDelegate<ZulipLocalizations> {
diff --git a/lib/generated/l10n/zulip_localizations_ar.dart b/lib/generated/l10n/zulip_localizations_ar.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Search emoji';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_en.dart b/lib/generated/l10n/zulip_localizations_en.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Search emoji';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_ja.dart b/lib/generated/l10n/zulip_localizations_ja.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Search emoji';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_nb.dart b/lib/generated/l10n/zulip_localizations_nb.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Search emoji';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_pl.dart b/lib/generated/l10n/zulip_localizations_pl.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Szukaj emoji';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_ru.dart b/lib/generated/l10n/zulip_localizations_ru.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Поиск эмодзи';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/generated/l10n/zulip_localizations_sk.dart b/lib/generated/l10n/zulip_localizations_sk.dart
@@ -537,4 +537,13 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
 
   @override
   String get emojiPickerSearchEmoji => 'Hľadať emotikon';
+
+  @override
+  String get actionSheetOptionEditMessage => 'Edit';
+
+  @override
+  String get errorEditingFailed => 'Failed to edit message';
+
+  @override
+  String get editMessageSaveTooltip => 'Save changes';
 }
diff --git a/lib/model/store.dart b/lib/model/store.dart
@@ -715,6 +715,16 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
     );
   }
 
+  Future<void> editMessage({required int messageId, required String content}) {
+    assert(!_disposed);
+
+    return _apiUpdateMessage(connection,
+      messageId: messageId,
+      content: content,
+      propagateMode: PropagateMode.changeOne,
+    );
+  }
+
   static List<CustomProfileField> _sortCustomProfileFields(List<CustomProfileField> initialCustomProfileFields) {
     // TODO(server): The realm-wide field objects have an `order` property,
     //   but the actual API appears to be that the fields should be shown in
@@ -735,6 +745,7 @@ class PerAccountStore extends ChangeNotifier with EmojiStore, ChannelStore, Mess
 }
 
 const _apiSendMessage = sendMessage; // Bit ugly; for alternatives, see: https://chat.zulip.org/#narrow/stream/243-mobile-team/topic/flutter.3A.20PerAccountStore.20methods/near/1545809
+const _apiUpdateMessage = updateMessage;
 const _tryResolveUrl = tryResolveUrl;
 
 /// Like [Uri.resolve], but on failure return null instead of throwing.
diff --git a/lib/widgets/action_sheet.dart b/lib/widgets/action_sheet.dart
@@ -390,13 +390,18 @@ void showMessageActionSheet({required BuildContext context, required Message mes
   final markAsUnreadSupported = store.connection.zulipFeatureLevel! >= 155; // TODO(server-6)
   final showMarkAsUnreadButton = markAsUnreadSupported && isMessageRead;
 
+  final canEditMessage = message.senderId == store.selfUserId
+    && messageListPage.narrow is! CombinedFeedNarrow;
+
   final optionButtons = [
     ReactionButtons(message: message, pageContext: context),
     StarButton(message: message, pageContext: context),
     if (isComposeBoxOffered)
       QuoteAndReplyButton(message: message, pageContext: context),
     if (showMarkAsUnreadButton)
       MarkAsUnreadButton(message: message, pageContext: context),
+    if (canEditMessage)
+      EditButton(message: message, pageContext: context),
     CopyMessageTextButton(message: message, pageContext: context),
     CopyMessageLinkButton(message: message, pageContext: context),
     ShareButton(message: message, pageContext: context),
@@ -708,6 +713,40 @@ class MarkAsUnreadButton extends MessageActionSheetMenuItemButton {
   }
 }
 
+class EditButton extends MessageActionSheetMenuItemButton {
+  EditButton({super.key, required super.message, required super.pageContext});
+
+  @override
+  IconData get icon => Icons.edit;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionEditMessage;
+  }
+
+  @override
+  void onPressed() async {
+    final zulipLocalizations = ZulipLocalizations.of(pageContext);
+    final rawContent = await fetchRawContentWithFeedback(
+      context: pageContext,
+      messageId: message.id,
+      errorDialogTitle: zulipLocalizations.errorEditingFailed,
+    );
+
+    if (rawContent == null) return;
+    if (!pageContext.mounted) return;
+
+    final messageListPage = findMessageListPage();
+    final composeBoxController = messageListPage.composeBoxController;
+
+    if (composeBoxController == null) return;
+
+    composeBoxController.startEditing(message);
+    composeBoxController.content.text = rawContent;
+    composeBoxController.contentFocusNode.requestFocus();
+  }
+}
+
 class CopyMessageTextButton extends MessageActionSheetMenuItemButton {
   CopyMessageTextButton({super.key, required super.message, required super.pageContext});
 
diff --git a/lib/widgets/compose_box.dart b/lib/widgets/compose_box.dart
@@ -971,48 +971,71 @@ class _SendButtonState extends State<_SendButton> {
   void _send() async {
     final controller = widget.controller;
 
-    if (_hasValidationErrors) {
-      final zulipLocalizations = ZulipLocalizations.of(context);
-      List<String> validationErrorMessages = [
-        for (final error in (controller is StreamComposeBoxController
-                              ? controller.topic.validationErrors
-                              : const <TopicValidationError>[]))
-          error.message(zulipLocalizations),
-        for (final error in controller.content.validationErrors)
-          error.message(zulipLocalizations),
-      ];
-      showErrorDialog(
-        context: context,
-        title: zulipLocalizations.errorMessageNotSent,
-        message: validationErrorMessages.join('\n\n'));
-      return;
-    }
-
-    final store = PerAccountStoreWidget.of(context);
-    final content = controller.content.textNormalized;
-
-    controller.content.clear();
-    // The following `stoppedComposing` call is currently redundant,
-    // because clearing input sends a "typing stopped" notice.
-    // It will be necessary once we resolve #720.
-    store.typingNotifier.stoppedComposing();
+    if (controller.isEditing && controller.messageBeingEdited != null) {
+      // Handle edit mode
+      try {
+        final store = PerAccountStoreWidget.of(context);
+        final content = controller.content.textNormalized;
+
+        await store.editMessage(
+          messageId: controller.messageBeingEdited!.id,
+          content: content,
+        );
+
+        controller.cancelEditing();
+      } on ApiRequestException catch (e) {
+        if (!mounted) return;
+        final zulipLocalizations = ZulipLocalizations.of(context);
+        showErrorDialog(
+          context: context,
+          title: zulipLocalizations.errorEditingFailed,
+          message: e.message);
+        return;
+      }
+    } else {
+      if (_hasValidationErrors) {
+        final zulipLocalizations = ZulipLocalizations.of(context);
+        List<String> validationErrorMessages = [
+          for (final error in (controller is StreamComposeBoxController
+                                ? controller.topic.validationErrors
+                                : const <TopicValidationError>[]))
+            error.message(zulipLocalizations),
+          for (final error in controller.content.validationErrors)
+            error.message(zulipLocalizations),
+        ];
+        showErrorDialog(
+          context: context,
+          title: zulipLocalizations.errorMessageNotSent,
+          message: validationErrorMessages.join('\n\n'));
+        return;
+      }
 
-    try {
-      // TODO(#720) clear content input only on success response;
-      //   while waiting, put input(s) and send button into a disabled
-      //   "working on it" state (letting input text be selected for copying).
-      await store.sendMessage(destination: widget.getDestination(), content: content);
-    } on ApiRequestException catch (e) {
-      if (!mounted) return;
-      final zulipLocalizations = ZulipLocalizations.of(context);
-      final message = switch (e) {
-        ZulipApiException() => zulipLocalizations.errorServerMessage(e.message),
-        _ => e.message,
-      };
-      showErrorDialog(context: context,
-        title: zulipLocalizations.errorMessageNotSent,
-        message: message);
-      return;
+      final store = PerAccountStoreWidget.of(context);
+      final content = controller.content.textNormalized;
+
+      controller.content.clear();
+      // The following `stoppedComposing` call is currently redundant,
+      // because clearing input sends a "typing stopped" notice.
+      // It will be necessary once we resolve #720.
+      store.typingNotifier.stoppedComposing();
+
+      try {
+        // TODO(#720) clear content input only on success response;
+        //   while waiting, put input(s) and send button into a disabled
+        //   "working on it" state (letting input text be selected for copying).
+        await store.sendMessage(destination: widget.getDestination(), content: content);
+      } on ApiRequestException catch (e) {
+        if (!mounted) return;
+        final zulipLocalizations = ZulipLocalizations.of(context);
+        final message = switch (e) {
+          ZulipApiException() => zulipLocalizations.errorServerMessage(e.message),
+          _ => e.message,
+        };
+        showErrorDialog(context: context,
+          title: zulipLocalizations.errorMessageNotSent,
+          message: message);
+        return;
+      }
     }
   }
 
@@ -1146,7 +1169,7 @@ abstract class _ComposeBoxBody extends StatelessWidget {
         child: Theme(
           data: inputThemeData,
           child: Column(children: [
-            if (topicInput != null) topicInput,
+            if (!controller.isEditing && topicInput != null) topicInput,
             buildContentInput(),
           ]))),
       SizedBox(
@@ -1219,6 +1242,21 @@ sealed class ComposeBoxController {
   final content = ComposeContentController();
   final contentFocusNode = FocusNode();
 
+  bool get isEditing => _messageBeingEdited != null;
+  Message? _messageBeingEdited;
+  Message? get messageBeingEdited => _messageBeingEdited;
+
+  void startEditing(Message message) {
+    _messageBeingEdited = message;
+    content.text = message.content;
+    contentFocusNode.requestFocus();
+  }
+
+  void cancelEditing() {
+    _messageBeingEdited = null;
+    content.clear();
+  }
+
   @mustCallSuper
   void dispose() {
     content.dispose();
