From 450ed8529dc97de2b9b1572d1358f3f071e6452d Mon Sep 17 00:00:00 2001
From: tyronetheqt <tyronetheqt@gmail.com>
Date: Sat, 13 Jun 2026 09:25:46 +0300
Subject: [PATCH] fix: use sans-serif font family on Linux when Twemoji is
 enabled

When Twemoji is set as a fontFamilyFallback on Linux with no explicit
fontFamily (null), the Flutter engine promotes the first fallback to
the primary font. This causes Twemoji to render all text glyphs,
resulting in missing characters for most UI text.

Fix this by setting fontFamily to "sans-serif" (resolved through
fontconfig) on Linux when Twemoji is enabled. On other platforms the
existing null behavior is preserved, since their font managers handle
fontFamilyFallback correctly.

As a related improvement, filter out Android-specific fonts (SystemFont,
Roboto) from the fallback fonts list on non-Android platforms.

Closes https://github.com/ExteraApp/Extera/issues/124
---
 lib/config/themes.dart | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/lib/config/themes.dart b/lib/config/themes.dart
index ef1380d7b..2bc7226c9 100644
--- a/lib/config/themes.dart
+++ b/lib/config/themes.dart
@@ -2,6 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
 import 'package:extera_next/config/setting_keys.dart';
+import 'package:extera_next/utils/platform_infos.dart';
 import 'app_config.dart';
 
 abstract class FluffyThemes {
@@ -18,6 +19,15 @@ abstract class FluffyThemes {
   static bool isThreeColumnMode(BuildContext context) =>
       MediaQuery.sizeOf(context).width > FluffyThemes.columnWidth * 3.5;
 
+  static List<String> _filteredFallbackFonts(String fonts) {
+    if (fonts.isEmpty) return const [];
+    final list = fonts.split(',');
+    if (!PlatformInfos.isAndroid) {
+      list.removeWhere((f) => f == 'SystemFont' || f == 'Roboto');
+    }
+    return list;
+  }
+
   static LinearGradient backgroundGradient(BuildContext context, int alpha) {
     final colorScheme = Theme.of(context).colorScheme;
     return LinearGradient(
@@ -81,16 +91,21 @@ abstract class FluffyThemes {
       brightness: brightness,
       colorScheme: colorScheme,
       useSystemColors: true,
-      fontFamily: AppSettings.systemFont.value
+      fontFamily: AppSettings.systemFont.value && PlatformInfos.isAndroid
           ? 'SystemFont'
-          : AppSettings.uiFont.value.isEmpty
-          ? null
-          : AppSettings.uiFont.value,
+          : AppSettings.uiFont.value.isNotEmpty
+          ? AppSettings.uiFont.value
+          : PlatformInfos.isLinux && twemoji == true
+          ? 'sans-serif'
+          : null,
       fontFamilyFallback: twemoji == true
-          ? ['Twemoji Mozilla', ...AppSettings.fallbackFonts.value.split(',')]
+          ? [
+              'Twemoji Mozilla',
+              ..._filteredFallbackFonts(AppSettings.fallbackFonts.value),
+            ]
           : AppSettings.fallbackFonts.value.isEmpty
           ? null
-          : AppSettings.fallbackFonts.value.split(','),
+          : _filteredFallbackFonts(AppSettings.fallbackFonts.value),
       dividerColor: brightness == Brightness.dark
           ? colorScheme.surfaceContainerHighest
           : colorScheme.surfaceContainer,