From 3ea7b8ed319806da27ac4e87376cdf9528d36907 Mon Sep 17 00:00:00 2001
From: Mikhail Matiunin <mikhail.matiunin@doctorina.com>
Date: Thu, 9 Oct 2025 18:16:26 +0400
Subject: [PATCH] Invalidate and relayout render object after system fonts
 changed

---
 CHANGELOG.md        |  6 +++++-
 lib/src/render.dart | 26 +++++++++++++++++++++++++-
 pubspec.yaml        |  2 +-
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 64e4d9e..e993711 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.0.8
+
+- **FIXED**: Invalidate and relayout render object after system fonts changed.
+
 ## 0.0.7
 
 - **FIXED**: Preserved indentation on line breaks within list items [#4].
@@ -7,7 +11,7 @@
 
 ## 0.0.6
 
-- **FIXED**: Fixed escaping of special characters. [#6] 
+- **FIXED**: Fixed escaping of special characters. [#6]
 
 ## 0.0.5
 
diff --git a/lib/src/render.dart b/lib/src/render.dart
index 72d93e1..957dd6b 100644
--- a/lib/src/render.dart
+++ b/lib/src/render.dart
@@ -98,11 +98,19 @@ class MarkdownRenderObject extends RenderBox {
     _painter.handleEvent(event);
   }
 
+  /// Handles system font changes by marking the render object as needing layout
+  void _handleSystemFontsChange() {
+    // Invalidate cached layouts in painter and all block painters
+    _painter.invalidateLayout();
+    // Request new layout and paint
+    markNeedsLayout();
+  }
+
   @override
   // ignore: unnecessary_overrides
   void attach(PipelineOwner owner) {
     super.attach(owner);
-    // Ensure the painter is mounted when the render object is attached.
+    PaintingBinding.instance.systemFonts.addListener(_handleSystemFontsChange);
   }
 
   /// Updates the render object with a new values.
@@ -124,6 +132,8 @@ class MarkdownRenderObject extends RenderBox {
   @override
   @protected
   void detach() {
+    PaintingBinding.instance.systemFonts
+        .removeListener(_handleSystemFontsChange);
     super.detach();
   }
 
@@ -264,6 +274,20 @@ class MarkdownPainter {
     return true; // Indicate that the painter was updated.
   }
 
+  /// Invalidate cached layouts when system fonts change.
+  /// This forces TextPainters to recreate their layouts with new fonts.
+  void invalidateLayout() {
+    _needsLayout = true;
+    _lastSize = null;
+    _lastPicture = null;
+    // Dispose and rebuild all block painters to recreate TextPainters
+    // with the new system fonts
+    for (final painter in _blockPainters) {
+      painter.dispose();
+    }
+    _rebuild();
+  }
+
   /// Layouts the markdown content with the given width.
   Size layout({required double maxWidth}) {
     if (_isEmpty) {
diff --git a/pubspec.yaml b/pubspec.yaml
index b7abed8..3be30af 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -8,7 +8,7 @@ description: >
   Markdown library written in Dart.
   It can parse and display Markdown.
 
-version: 0.0.7
+version: 0.0.8
 
 homepage: https://github.com/DoctorinaAI/md
 repository: https://github.com/DoctorinaAI/md