Edit-message (8/n): Implement edit-message!

assets/l10n/app_en.arb

@@ -144,6 +144,10 @@
   "@actionSheetOptionUnstarMessage":  {
     "description": "Label for unstar button on action sheet."
   },
+  "actionSheetOptionEditMessage": "Edit message",
+  "@actionSheetOptionEditMessage": {
+    "description": "Label for the 'Edit message' button in the message action sheet."
+  },
   "actionSheetOptionMarkTopicAsRead": "Mark topic as read",
   "@actionSheetOptionMarkTopicAsRead": {
     "description": "Option to mark a specific topic as read in the action sheet."
@@ -168,7 +172,7 @@
       "server": {"type": "String", "example": "https://example.com"}
     }
   },
-  "errorCouldNotFetchMessageSource": "Could not fetch message source",
+  "errorCouldNotFetchMessageSource": "Could not fetch message source.",
   "@errorCouldNotFetchMessageSource": {
     "description": "Error message when the source of a message could not be fetched."
   },
@@ -219,6 +223,10 @@
   "@errorMessageNotSent": {
     "description": "Error message for compose box when a message could not be sent."
   },
+  "errorMessageEditNotSaved": "Message not saved",
+  "@errorMessageEditNotSaved": {
+    "description": "Error message for compose box when a message edit could not be saved."
+  },
   "errorLoginCouldNotConnect": "Failed to connect to server:\n{url}",
   "@errorLoginCouldNotConnect": {
     "description": "Error message when the app could not connect to the server.",
@@ -309,6 +317,10 @@
   "@errorUnstarMessageFailedTitle": {
     "description": "Error title when unstarring a message failed."
   },
+  "errorCouldNotEditMessageTitle": "Could not edit message",
+  "@errorCouldNotEditMessageTitle": {
+    "description": "Error title when an exception prevented us from opening the compose box for editing a message."
+  },
   "successLinkCopied": "Link copied",
   "@successLinkCopied": {
     "description": "Success message after copy link action completed."
@@ -329,6 +341,46 @@
   "@errorBannerCannotPostInChannelLabel": {
     "description": "Error-banner text replacing the compose box when you do not have permission to send a message to the channel."
   },
+  "composeBoxBannerLabelEditMessage": "Edit message",
+  "@composeBoxBannerLabelEditMessage": {
+    "description": "Label text for the compose-box banner when you are editing a message."
+  },
+  "composeBoxBannerButtonCancel": "Cancel",
+  "@composeBoxBannerButtonCancel": {
+    "description": "Label text for the 'Cancel' button in the compose-box banner when you are editing a message."
+  },
+  "composeBoxBannerButtonSave": "Save",
+  "@composeBoxBannerButtonSave": {
+    "description": "Label text for the 'Save' button in the compose-box banner when you are editing a message."
+  },
+  "editAlreadyInProgressTitle": "Cannot edit message",
+  "@editAlreadyInProgressTitle": {
+    "description": "Error title when a message edit cannot be saved because there is another edit already in progress."
+  },
+  "editAlreadyInProgressMessage": "An edit is already in progress. Please wait for it to complete.",
+  "@editAlreadyInProgressMessage": {
+    "description": "Error message when a message edit cannot be saved because there is another edit already in progress."
+  },
+  "savingMessageEditLabel": "SAVING EDIT…",
+  "@savingMessageEditLabel": {
+    "description": "Text on a message in the message list saying that a message edit request is processing. (Use ALL CAPS for cased alphabets: Latin, Greek, Cyrillic, etc.)"
+  },
+  "savingMessageEditFailedLabel": "EDIT NOT SAVED",
+  "@savingMessageEditFailedLabel": {
+    "description": "Text on a message in the message list saying that a message edit request failed. (Use ALL CAPS for cased alphabets: Latin, Greek, Cyrillic, etc.)"
+  },
+  "discardDraftConfirmationDialogTitle": "Discard the message you’re writing?",
+  "@discardDraftConfirmationDialogTitle": {
+    "description": "Title for a confirmation dialog for discarding message text that was typed into the compose box."
+  },
+  "discardDraftConfirmationDialogMessage": "When you edit a message, the content that was previously in the compose box is discarded.",
+  "@discardDraftConfirmationDialogMessage": {
+    "description": "Message for a confirmation dialog for discarding message text that was typed into the compose box."
+  },
+  "discardDraftConfirmationDialogConfirmButton": "Discard",
+  "@discardDraftConfirmationDialogConfirmButton": {
+    "description": "Label for the 'Discard' button on a confirmation dialog for discarding message text that was typed into the compose box."
+  },
   "composeBoxAttachFilesTooltip": "Attach files",
   "@composeBoxAttachFilesTooltip": {
     "description": "Tooltip for compose box icon to attach a file to the message."
@@ -367,6 +419,10 @@
       "destination": {"type": "String", "example": "#channel name > topic name"}
     }
   },
+  "preparingEditMessageContentInput": "Preparing…",
+  "@preparingEditMessageContentInput": {
+    "description": "Hint text for content input when the compose box is preparing to edit a message."
+  },
   "composeBoxSendTooltip": "Send",
   "@composeBoxSendTooltip":  {
     "description": "Tooltip for send button in compose box."
@@ -561,7 +617,7 @@
       "url": {"type": "String", "example": "http://chat.example.com/"}
     }
   },
-  "errorInvalidResponse": "The server sent an invalid response",
+  "errorInvalidResponse": "The server sent an invalid response.",
   "@errorInvalidResponse": {
     "description": "Error message when an API call returned an invalid response."
   },
@@ -591,7 +647,7 @@
       "httpStatus": {"type": "int", "example": "500"}
     }
   },
-  "errorVideoPlayerFailed": "Unable to play the video",
+  "errorVideoPlayerFailed": "Unable to play the video.",
   "@errorVideoPlayerFailed": {
     "description": "Error message when a video fails to play."
   },

lib/api/model/submessage.dart

@@ -64,6 +64,7 @@ class Submessage {
           widgetData: widgetData,
           pollEventSubmessages: submessages.skip(1),
           messageSenderId: messageSenderId,
+          debugSubmessages: kDebugMode ? submessages : null,
         );
       case UnsupportedWidgetData():
         assert(debugLog('Unsupported widgetData: ${widgetData.json}'));
@@ -368,11 +369,13 @@ class Poll extends ChangeNotifier {
     required PollWidgetData widgetData,
     required Iterable<Submessage> pollEventSubmessages,
     required int messageSenderId,
+    required List<Submessage>? debugSubmessages,
   }) {
     final poll = Poll._(
       messageSenderId: messageSenderId,
       question: widgetData.extraData.question,
       options: widgetData.extraData.options,
+      debugSubmessages: debugSubmessages,
     );
 
     for (final submessage in pollEventSubmessages) {
@@ -386,17 +389,23 @@ class Poll extends ChangeNotifier {
     required this.messageSenderId,
     required this.question,
     required List<String> options,
+    required List<Submessage>? debugSubmessages,
   }) {
     for (int index = 0; index < options.length; index += 1) {
       // Initial poll options use a placeholder senderId.
       // See [PollEventSubmessage.optionKey] for details.
       _addOption(senderId: null, idx: index, option: options[index]);
     }
+    if (kDebugMode) {
+      _debugSubmessages = debugSubmessages;
+    }
   }
 
   final int messageSenderId;
   String question;
 
+  List<Submessage>? _debugSubmessages;
+
   /// The limit of options any single user can add to a poll.
   ///
   /// See https://github.com/zulip/zulip/blob/304d948416465c1a085122af5d752f03d6797003/web/shared/src/poll_data.ts#L69-L71
@@ -417,6 +426,14 @@ class Poll extends ChangeNotifier {
     }
     _applyEvent(event.senderId, pollEventSubmessage);
     notifyListeners();
+
+    if (kDebugMode) {
+      assert(_debugSubmessages != null);
+      _debugSubmessages!.add(Submessage(
+        senderId: event.senderId,
+        msgType: event.msgType,
+        content: event.content));
+    }
   }
 
   void _applyEvent(int senderId, PollEventSubmessage event) {
@@ -472,9 +489,18 @@ class Poll extends ChangeNotifier {
   }
 
   static List<Submessage> toJson(Poll? poll) {
-    // Rather than maintaining a up-to-date submessages list, return as if it is
-    // empty, because we are not sending the submessages to the server anyway.
-    return [];
+    List<Submessage>? result;
+
+    if (kDebugMode) {
+      // Useful for setting up a message list with a poll message, which goes
+      // through this codepath (when preparing a fetch response).
+      result = poll?._debugSubmessages;
+    }
+
+    // In prod, rather than maintaining a up-to-date submessages list,
+    // return as if it is empty, because we are not sending the submessages
+    // to the server anyway.
+    return result ?? [];
   }
 }
 

lib/generated/l10n/zulip_localizations.dart

@@ -326,6 +326,12 @@ abstract class ZulipLocalizations {
   /// **'Unstar message'**
   String get actionSheetOptionUnstarMessage;
 
+  /// Label for the 'Edit message' button in the message action sheet.
+  ///
+  /// In en, this message translates to:
+  /// **'Edit message'**
+  String get actionSheetOptionEditMessage;
+
   /// Option to mark a specific topic as read in the action sheet.
   ///
   /// In en, this message translates to:
@@ -359,7 +365,7 @@ abstract class ZulipLocalizations {
   /// Error message when the source of a message could not be fetched.
   ///
   /// In en, this message translates to:
-  /// **'Could not fetch message source'**
+  /// **'Could not fetch message source.'**
   String get errorCouldNotFetchMessageSource;
 
   /// Error message when copying the text of a message to the user's system clipboard failed.
@@ -414,6 +420,12 @@ abstract class ZulipLocalizations {
   /// **'Message not sent'**
   String get errorMessageNotSent;
 
+  /// Error message for compose box when a message edit could not be saved.
+  ///
+  /// In en, this message translates to:
+  /// **'Message not saved'**
+  String get errorMessageEditNotSaved;
+
   /// Error message when the app could not connect to the server.
   ///
   /// In en, this message translates to:
@@ -526,6 +538,12 @@ abstract class ZulipLocalizations {
   /// **'Failed to unstar message'**
   String get errorUnstarMessageFailedTitle;
 
+  /// Error title when an exception prevented us from opening the compose box for editing a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Could not edit message'**
+  String get errorCouldNotEditMessageTitle;
+
   /// Success message after copy link action completed.
   ///
   /// In en, this message translates to:
@@ -556,6 +574,66 @@ abstract class ZulipLocalizations {
   /// **'You do not have permission to post in this channel.'**
   String get errorBannerCannotPostInChannelLabel;
 
+  /// Label text for the compose-box banner when you are editing a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Edit message'**
+  String get composeBoxBannerLabelEditMessage;
+
+  /// Label text for the 'Cancel' button in the compose-box banner when you are editing a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Cancel'**
+  String get composeBoxBannerButtonCancel;
+
+  /// Label text for the 'Save' button in the compose-box banner when you are editing a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Save'**
+  String get composeBoxBannerButtonSave;
+
+  /// Error title when a message edit cannot be saved because there is another edit already in progress.
+  ///
+  /// In en, this message translates to:
+  /// **'Cannot edit message'**
+  String get editAlreadyInProgressTitle;
+
+  /// Error message when a message edit cannot be saved because there is another edit already in progress.
+  ///
+  /// In en, this message translates to:
+  /// **'An edit is already in progress. Please wait for it to complete.'**
+  String get editAlreadyInProgressMessage;
+
+  /// Text on a message in the message list saying that a message edit request is processing. (Use ALL CAPS for cased alphabets: Latin, Greek, Cyrillic, etc.)
+  ///
+  /// In en, this message translates to:
+  /// **'SAVING EDIT…'**
+  String get savingMessageEditLabel;
+
+  /// Text on a message in the message list saying that a message edit request failed. (Use ALL CAPS for cased alphabets: Latin, Greek, Cyrillic, etc.)
+  ///
+  /// In en, this message translates to:
+  /// **'EDIT NOT SAVED'**
+  String get savingMessageEditFailedLabel;
+
+  /// Title for a confirmation dialog for discarding message text that was typed into the compose box.
+  ///
+  /// In en, this message translates to:
+  /// **'Discard the message you’re writing?'**
+  String get discardDraftConfirmationDialogTitle;
+
+  /// Message for a confirmation dialog for discarding message text that was typed into the compose box.
+  ///
+  /// In en, this message translates to:
+  /// **'When you edit a message, the content that was previously in the compose box is discarded.'**
+  String get discardDraftConfirmationDialogMessage;
+
+  /// Label for the 'Discard' button on a confirmation dialog for discarding message text that was typed into the compose box.
+  ///
+  /// In en, this message translates to:
+  /// **'Discard'**
+  String get discardDraftConfirmationDialogConfirmButton;
+
   /// Tooltip for compose box icon to attach a file to the message.
   ///
   /// In en, this message translates to:
@@ -604,6 +682,12 @@ abstract class ZulipLocalizations {
   /// **'Message {destination}'**
   String composeBoxChannelContentHint(String destination);
 
+  /// Hint text for content input when the compose box is preparing to edit a message.
+  ///
+  /// In en, this message translates to:
+  /// **'Preparing…'**
+  String get preparingEditMessageContentInput;
+
   /// Tooltip for send button in compose box.
   ///
   /// In en, this message translates to:
@@ -863,7 +947,7 @@ abstract class ZulipLocalizations {
   /// Error message when an API call returned an invalid response.
   ///
   /// In en, this message translates to:
-  /// **'The server sent an invalid response'**
+  /// **'The server sent an invalid response.'**
   String get errorInvalidResponse;
 
   /// Error message when a network request fails.
@@ -893,7 +977,7 @@ abstract class ZulipLocalizations {
   /// Error message when a video fails to play.
   ///
   /// In en, this message translates to:
-  /// **'Unable to play the video'**
+  /// **'Unable to play the video.'**
   String get errorVideoPlayerFailed;
 
   /// Error message when URL is empty