content: Revise "unimplemented content" UX

assets/l10n/app_en.arb

@@ -1070,5 +1070,21 @@
   "zulipAppTitle": "Zulip",
   "@zulipAppTitle": {
     "description": "The name of Zulip. This should be either 'Zulip' or a transliteration."
+  },
+  "errorUnimplementedHeader": "Error displaying content",
+  "errorUnimplementedWhatHappened": "What Happened?",
+  "errorUnimplementedDescription": "Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.",
+  "errorUnimplementedHtmlHeading": "HTML",
+  "@errorUnimplementedHeader": {
+    "description": "Header for an error screen explaining that content could not be displayed."
+  },
+  "@errorUnimplementedWhatHappened": {
+    "description": "Label for explaining what happened in an error screen."
+  },
+  "@errorUnimplementedDescription": {
+    "description": "Detailed description of an error that explains why content could not be displayed."
+  },
+  "@errorUnimplementedHtmlHeading": {
+    "description": "Heading for HTML section in an error screen."
   }
 }

lib/generated/l10n/zulip_localizations.dart

@@ -1598,6 +1598,30 @@ abstract class ZulipLocalizations {
   /// In en, this message translates to:
   /// **'Zulip'**
   String get zulipAppTitle;
+
+  /// Header for an error screen explaining that content could not be displayed.
+  ///
+  /// In en, this message translates to:
+  /// **'Error displaying content'**
+  String get errorUnimplementedHeader;
+
+  /// Label for explaining what happened in an error screen.
+  ///
+  /// In en, this message translates to:
+  /// **'What Happened?'**
+  String get errorUnimplementedWhatHappened;
+
+  /// Detailed description of an error that explains why content could not be displayed.
+  ///
+  /// In en, this message translates to:
+  /// **'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.'**
+  String get errorUnimplementedDescription;
+
+  /// Heading for HTML section in an error screen.
+  ///
+  /// In en, this message translates to:
+  /// **'HTML'**
+  String get errorUnimplementedHtmlHeading;
 }
 
 class _ZulipLocalizationsDelegate

lib/generated/l10n/zulip_localizations_ar.dart

@@ -871,4 +871,17 @@ class ZulipLocalizationsAr extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_de.dart

@@ -899,4 +899,17 @@ class ZulipLocalizationsDe extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_en.dart

@@ -871,6 +871,19 @@ class ZulipLocalizationsEn extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }
 
 /// The translations for English, as used in the United Kingdom (`en_GB`).

lib/generated/l10n/zulip_localizations_it.dart

@@ -893,4 +893,17 @@ class ZulipLocalizationsIt extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_ja.dart

@@ -871,4 +871,17 @@ class ZulipLocalizationsJa extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_nb.dart

@@ -871,4 +871,17 @@ class ZulipLocalizationsNb extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_pl.dart

@@ -884,4 +884,17 @@ class ZulipLocalizationsPl extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_ru.dart

@@ -888,4 +888,17 @@ class ZulipLocalizationsRu extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_sk.dart

@@ -873,4 +873,17 @@ class ZulipLocalizationsSk extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_sl.dart

@@ -900,4 +900,17 @@ class ZulipLocalizationsSl extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_uk.dart

@@ -889,4 +889,17 @@ class ZulipLocalizationsUk extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }

lib/generated/l10n/zulip_localizations_zh.dart

@@ -871,6 +871,19 @@ class ZulipLocalizationsZh extends ZulipLocalizations {
 
   @override
   String get zulipAppTitle => 'Zulip';
+
+  @override
+  String get errorUnimplementedHeader => 'Error displaying content';
+
+  @override
+  String get errorUnimplementedWhatHappened => 'What Happened?';
+
+  @override
+  String get errorUnimplementedDescription =>
+      'Zulip is primarily a desktop-oriented app, where messages are received and displayed in HTML format as-is. However, on the mobile app, HTML must be converted into a format called ContentNode in order to display messages properly. This error occurred because the received HTML could not be converted into a ContentNode.';
+
+  @override
+  String get errorUnimplementedHtmlHeading => 'HTML';
 }
 
 /// The translations for Chinese, as used in China, using the Han script (`zh_Hans_CN`).