compose: Translate "(loading message {messageId})"

and implement the necessary plumbing to access ZulipLocalizations

Signed-off-by: Zixuan James Li <zixuan@zulip.com>

Author: PIG208

assets/l10n/app_en.arb

@@ -351,6 +351,13 @@
       "filename": {"type": "String", "example": "file.txt"}
     }
   },
+  "composeBoxLoadingMessage": "(loading message {messageId})",
+  "@composeBoxLoadingMessage": {
+    "description": "Placeholder in compose box showing the quoted message is currently loading.",
+    "placeholders": {
+      "messageId": {"type": "int", "example": "1234"}
+    }
+  },
   "unknownUserName": "(unknown user)",
   "@unknownUserName": {
     "description": "Name placeholder to use for a user when we don't know their name."

lib/generated/l10n/zulip_localizations.dart

@@ -567,6 +567,12 @@ abstract class ZulipLocalizations {
   /// **'Uploading {filename}…'**
   String composeBoxUploadingFilename(String filename);
 
+  /// Placeholder in compose box showing the quoted message is currently loading.
+  ///
+  /// In en, this message translates to:
+  /// **'(loading message {messageId})'**
+  String composeBoxLoadingMessage(int messageId);
+
   /// Name placeholder to use for a user when we don't know their name.
   ///
   /// In en, this message translates to:

lib/generated/l10n/zulip_localizations_ar.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
     return 'Uploading $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(unknown user)';
 

lib/generated/l10n/zulip_localizations_en.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
     return 'Uploading $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(unknown user)';
 

lib/generated/l10n/zulip_localizations_ja.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
     return 'Uploading $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(unknown user)';
 

lib/generated/l10n/zulip_localizations_nb.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
     return 'Uploading $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(unknown user)';
 

lib/generated/l10n/zulip_localizations_pl.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
     return 'Przekazywanie $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(nieznany użytkownik)';
 

lib/generated/l10n/zulip_localizations_ru.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
     return 'Загрузка $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(неизвестный пользователь)';
 

lib/generated/l10n/zulip_localizations_sk.dart

@@ -277,6 +277,11 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
     return 'Uploading $filename…';
   }
 
+  @override
+  String composeBoxLoadingMessage(int messageId) {
+    return '(loading message $messageId)';
+  }
+
   @override
   String get unknownUserName => '(unknown user)';
 

lib/model/compose.dart

@@ -1,6 +1,7 @@
 import 'dart:math';
 
 import '../api/model/model.dart';
+import '../generated/l10n/zulip_localizations.dart';
 import 'internal_link.dart';
 import 'narrow.dart';
 import 'store.dart';
@@ -136,7 +137,9 @@ String inlineLink(String visibleText, Uri? destination) {
 }
 
 /// What we show while fetching the target message's raw Markdown.
-String quoteAndReplyPlaceholder(PerAccountStore store, {
+String quoteAndReplyPlaceholder(
+  ZulipLocalizations zulipLocalizations,
+  PerAccountStore store, {
   required Message message,
 }) {
   final sender = store.users[message.senderId];
@@ -146,7 +149,7 @@ String quoteAndReplyPlaceholder(PerAccountStore store, {
     nearMessageId: message.id);
   // See note in [quoteAndReply] about asking `mention` to omit the |<id> part.
   return '${mention(sender!, silent: true)} ${inlineLink('said', url)}: ' // TODO(#1285)
-    '*(loading message ${message.id})*\n'; // TODO(i18n) ?
+    '*${zulipLocalizations.composeBoxLoadingMessage(message.id)}*\n';
 }
 
 /// Quote-and-reply syntax.