intl: replace all hard-coded strings to be wired into localization framework

Fixes: #277

Author: sirpengi

lib/api/core.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 import 'dart:io';
 
+import 'package:flutter_gen/gen_l10n/zulip_localizations.dart';
 import 'package:http/http.dart' as http;
 
 import '../log.dart';
@@ -84,15 +85,25 @@ class ApiConnection {
     try {
       response = await _client.send(request);
     } catch (e) {
-      final String message;
+      final String? message;
+      final String Function(ZulipLocalizations)? translatableMessage;
       if (e is http.ClientException) {
         message = e.message;
+        translatableMessage = null;
       } else if (e is TlsException) {
         message = e.message;
+        translatableMessage = null;
       } else {
-        message = 'Network request failed';
+        message = null;
+        translatableMessage = (ZulipLocalizations zulipLocalizations) {
+          return zulipLocalizations.apiConnectionNetworkRequestFailed;
+        };
       }
-      throw NetworkException(routeName: routeName, cause: e, message: message);
+      throw NetworkException(
+        routeName: routeName,
+        cause: e,
+        message: message,
+        translatableMessage: translatableMessage);
     }
 
     final int httpStatus = response.statusCode;
@@ -173,6 +184,7 @@ ApiRequestException _makeApiException(String routeName, int httpStatus, Map<Stri
         // TODO(server): `code` should always be present.  Get the "Invalid API key" case fixed.
         code: json.remove('code') ?? 'BAD_REQUEST',
         message: json.remove('msg'),
+        translatableMessage: null,
         data: json,
       );
     }

lib/api/exception.dart

@@ -1,4 +1,6 @@
 
+import 'package:flutter_gen/gen_l10n/zulip_localizations.dart';
+
 /// Some kind of error from a Zulip API network request.
 sealed class ApiRequestException implements Exception {
   /// The name of the Zulip API route for the request.
@@ -11,13 +13,26 @@ sealed class ApiRequestException implements Exception {
   /// and its route name would be "getMessages".
   final String routeName;
 
-  /// A user-facing description of the error.
+  /// Server supplied user-facing description of the error.
+  ///
+  /// For [ZulipApiException] this may be supplied by the server as the `message`
+  /// property in the JSON response.
+  // TODO(i18n): no method yet to translate a server provided string.
+  final String? message;
+
+  /// App supplied user-facing description of the error.
   ///
-  /// For [ZulipApiException] this is supplied by the server as the `message`
-  /// property in the JSON response, and is translated into the user's language.
-  final String message;
+  /// This description will be translated according to the
+  /// current set locale.
+  final String Function(ZulipLocalizations)? translatableMessage;
+
+  ApiRequestException({required this.routeName, required this.message, required this.translatableMessage});
 
-  ApiRequestException({required this.routeName, required this.message});
+  String toTranslatedString(ZulipLocalizations zulipLocalizations) {
+    return (translatableMessage != null)
+      ? translatableMessage!(zulipLocalizations)
+      : super.toString();
+  }
 }
 
 /// An error returned through the Zulip server API.
@@ -46,6 +61,7 @@ class ZulipApiException extends ApiRequestException {
     required this.httpStatus,
     required this.data,
     required super.message,
+    required super.translatableMessage,
   }) : assert(400 <= httpStatus && httpStatus <= 499);
 }
 
@@ -58,7 +74,7 @@ class NetworkException extends ApiRequestException {
   /// but empirically it can be [TlsException] and possibly others.
   final Object cause;
 
-  NetworkException({required super.routeName, required super.message, required this.cause});
+  NetworkException({required super.routeName, required super.message, required super.translatableMessage, required this.cause});
 }
 
 /// Some kind of server-side error in handling the request.
@@ -79,6 +95,7 @@ abstract class ServerException extends ApiRequestException {
     required this.httpStatus,
     required this.data,
     required super.message,
+    required super.translatableMessage,
   });
 }
 
@@ -89,7 +106,11 @@ class Server5xxException extends ServerException {
     required super.httpStatus,
     required super.data,
   }) : assert(500 <= httpStatus && httpStatus <= 599),
-       super(message: 'Network request failed: HTTP status $httpStatus'); // TODO(i18n)
+       super(
+         message: null,
+         translatableMessage: (ZulipLocalizations zulipLocalizations) {
+           return zulipLocalizations.serverExceptionRequestFailed(httpStatus);
+         });
 }
 
 /// An error where the server's response doesn't match the Zulip API.
@@ -110,5 +131,9 @@ class MalformedServerResponseException extends ServerException {
     required super.routeName,
     required super.httpStatus,
     required super.data,
-  }) : super(message: 'Server gave malformed response; HTTP status $httpStatus'); // TODO(i18n)
+  }) : super(
+         message: null,
+         translatableMessage: (ZulipLocalizations zulipLocalizations) {
+           return zulipLocalizations.serverExceptionMalformedResponse(httpStatus);
+         });
 }

lib/widgets/action_sheet.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
+import 'package:flutter_gen/gen_l10n/zulip_localizations.dart';
 import 'package:share_plus/share_plus.dart';
 
 import '../api/exception.dart';
@@ -43,18 +44,19 @@ abstract class MessageActionSheetMenuItemButton extends StatelessWidget {
   }) : assert(messageListContext.findAncestorWidgetOfExactType<MessageListPage>() != null);
 
   IconData get icon;
-  String get label;
+  String Function(ZulipLocalizations) get translateLabel;
   void Function(BuildContext) get onPressed;
 
   final Message message;
   final BuildContext messageListContext;
 
   @override
   Widget build(BuildContext context) {
+    final zulipLocalizations = ZulipLocalizations.of(context);
     return MenuItemButton(
       leadingIcon: Icon(icon),
       onPressed: () => onPressed(context),
-      child: Text(label));
+      child: Text(translateLabel(zulipLocalizations)));
   }
 }
 
@@ -67,7 +69,9 @@ class ShareButton extends MessageActionSheetMenuItemButton {
 
   @override get icon => Icons.adaptive.share;
 
-  @override get label => 'Share';
+  @override get translateLabel => (ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetShare;
+  };
 
   @override get onPressed => (BuildContext context) async {
     // Close the message action sheet; we're about to show the share
@@ -104,22 +108,23 @@ Future<String?> fetchRawContentWithFeedback({
     // - If request(s) take(s) a long time, show snackbar with cancel
     //   button, like "Still working on quote-and-reply…".
     //   On final failure or success, auto-dismiss the snackbar.
+    final zulipLocalizations = ZulipLocalizations.of(context);
     try {
       fetchedMessage = await getMessageCompat(PerAccountStoreWidget.of(context).connection,
         messageId: messageId,
         applyMarkdown: false,
       );
       if (fetchedMessage == null) {
-        errorMessage = 'That message does not seem to exist.';
+        errorMessage = zulipLocalizations.actionSheetMessageDoesNotSeemToExist;
       }
     } catch (e) {
       switch (e) {
         case ZulipApiException():
-          errorMessage = e.message;
+          errorMessage = e.toTranslatedString(zulipLocalizations);
         // TODO specific messages for common errors, like network errors
         //   (support with reusable code)
         default:
-          errorMessage = 'Could not fetch message source.';
+          errorMessage = zulipLocalizations.actionSheetCouldNotFetchMessageSource;
       }
     }
 
@@ -146,12 +151,15 @@ class QuoteAndReplyButton extends MessageActionSheetMenuItemButton {
 
   @override get icon => Icons.format_quote_outlined;
 
-  @override get label => 'Quote and reply';
+  @override get translateLabel => (ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetQuoteAndReply;
+  };
 
   @override get onPressed => (BuildContext bottomSheetContext) async {
     // Close the message action sheet. We'll show the request progress
     // in the compose-box content input with a "[Quoting…]" placeholder.
     Navigator.of(bottomSheetContext).pop();
+    final zulipLocalizations = ZulipLocalizations.of(messageListContext);
 
     // This will be null only if the compose box disappeared after the
     // message action sheet opened, and before "Quote and reply" was pressed.
@@ -174,7 +182,7 @@ class QuoteAndReplyButton extends MessageActionSheetMenuItemButton {
     final rawContent = await fetchRawContentWithFeedback(
       context: messageListContext,
       messageId: message.id,
-      errorDialogTitle: 'Quotation failed',
+      errorDialogTitle: zulipLocalizations.actionSheetQuotationFailed,
     );
 
     if (!messageListContext.mounted) return;
@@ -203,26 +211,29 @@ class CopyButton extends MessageActionSheetMenuItemButton {
 
   @override get icon => Icons.copy;
 
-  @override get label => 'Copy message text';
+  @override get translateLabel => (ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetCopyMessageText;
+  };
 
   @override get onPressed => (BuildContext context) async {
     // Close the message action sheet. We won't be showing request progress,
     // but hopefully it won't take long at all, and
     // fetchRawContentWithFeedback has a TODO for giving feedback if it does.
     Navigator.of(context).pop();
+    final zulipLocalizations = ZulipLocalizations.of(messageListContext);
 
     final rawContent = await fetchRawContentWithFeedback(
       context: messageListContext,
       messageId: message.id,
-      errorDialogTitle: 'Copying failed',
+      errorDialogTitle: zulipLocalizations.actionSheetCopyingFailed,
     );
 
     if (rawContent == null) return;
 
     if (!messageListContext.mounted) return;
 
-    // TODO(i18n)
-    copyWithPopup(context: context, successContent: const Text('Message copied'),
+    copyWithPopup(context: context,
+      successContent: Text(zulipLocalizations.actionSheetMessageCopied),
       data: ClipboardData(text: rawContent));
   };
 }