From 2a4704e5b5dd5ba34abad51b9e2ab91cdc5a6438 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 20:40:35 +0800
Subject: [PATCH 01/13] feat: add Windows title bar theme support based on app
 theme

---
 lib/app_widget.dart                         |  9 ++++
 lib/pages/settings/theme_settings_page.dart | 17 ++++++++
 lib/utils/utils.dart                        | 22 ++++++++++
 windows/runner/flutter_window.cpp           | 36 ++++++++++++++++
 windows/runner/flutter_window.h             |  3 ++
 windows/runner/win32_window.cpp             | 46 +++++++++++++++------
 windows/runner/win32_window.h               | 13 ++++--
 7 files changed, 131 insertions(+), 15 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index 78ad8aeca..97a88d61a 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -215,6 +215,15 @@ class _AppWidgetState extends State<AppWidget>
     if (defaultThemeMode == 'system') {
       themeProvider.setThemeMode(ThemeMode.system, notify: false);
     }
+
+    // Set Windows title bar theme based on app theme
+    if (Platform.isWindows) {
+      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+      final isDark = themeProvider.themeMode == ThemeMode.dark ||
+          (themeProvider.themeMode == ThemeMode.system && brightness == Brightness.dark);
+      Utils.setWindowTitleBarDarkMode(isDark);
+    }
+
     themeProvider.setFontFamily(useSystemFont, notify: false);
     var defaultDarkTheme = ThemeData(
         useMaterial3: true,
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index 90d9dd0bc..c840adcc3 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -122,6 +122,13 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
     setState(() {
       defaultThemeMode = theme;
     });
+
+    // Update Windows title bar theme
+    if (Utils.isDesktop() && Platform.isWindows) {
+      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+      final isDark = theme == 'dark' || (theme == 'system' && brightness == Brightness.dark);
+      Utils.setWindowTitleBarDarkMode(isDark);
+    }
   }
 
   void updateOledEnhance() {
@@ -382,6 +389,16 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
                       showWindowButton = value ?? !showWindowButton;
                       await setting.put(
                           SettingBoxKey.showWindowButton, showWindowButton);
+                      // Reset title bar theme to follow system when hiding system title bar
+                      if (!showWindowButton && Platform.isWindows) {
+                        Utils.resetWindowTitleBarTheme();
+                      } else if (showWindowButton && Platform.isWindows) {
+                        // Update title bar theme based on current app theme when showing system title bar
+                        final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+                        final isDark = defaultThemeMode == 'dark' ||
+                            (defaultThemeMode == 'system' && brightness == Brightness.dark);
+                        Utils.setWindowTitleBarDarkMode(isDark);
+                      }
                       setState(() {});
                     },
                     title: Text('使用系统标题栏',
diff --git a/lib/utils/utils.dart b/lib/utils/utils.dart
index 1fdd4773b..8c93cab76 100644
--- a/lib/utils/utils.dart
+++ b/lib/utils/utils.dart
@@ -700,4 +700,26 @@ class Utils {
       action?.call();
     });
   }
+
+  /// 设置 Windows 标题栏深色模式
+  static Future<void> setWindowTitleBarDarkMode(bool isDark) async {
+    if (!Platform.isWindows) return;
+    const MethodChannel themeChannel = MethodChannel("com.predidit.kazumi/theme");
+    try {
+      await themeChannel.invokeMethod("setTitleBarDarkMode", {"isDark": isDark});
+    } on PlatformException catch (e) {
+      KazumiLogger().e("Failed to set title bar dark mode: '${e.message}'.");
+    }
+  }
+
+  /// 重置 Windows 标题栏跟随系统主题
+  static Future<void> resetWindowTitleBarTheme() async {
+    if (!Platform.isWindows) return;
+    const MethodChannel themeChannel = MethodChannel("com.predidit.kazumi/theme");
+    try {
+      await themeChannel.invokeMethod("resetTitleBarTheme");
+    } on PlatformException catch (e) {
+      KazumiLogger().e("Failed to reset title bar theme: '${e.message}'.");
+    }
+  }
 }
\ No newline at end of file
diff --git a/windows/runner/flutter_window.cpp b/windows/runner/flutter_window.cpp
index f16880f9a..3815ef065 100644
--- a/windows/runner/flutter_window.cpp
+++ b/windows/runner/flutter_window.cpp
@@ -54,6 +54,9 @@ bool FlutterWindow::OnCreate() {
   // Register Shortcut MethodChannel
   RegisterShortcutChannel();
 
+  // Register Theme MethodChannel
+  RegisterThemeChannel();
+
   return true;
 }
 
@@ -176,3 +179,36 @@ void FlutterWindow::RegisterShortcutChannel() {
     }
   });
 }
+
+// Theme MethodChannel setup for immersive title bar
+void FlutterWindow::RegisterThemeChannel() {
+  auto channel = std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
+      flutter_controller_->engine()->messenger(), "com.predidit.kazumi/theme",
+      &flutter::StandardMethodCodec::GetInstance());
+
+  channel->SetMethodCallHandler([this](const auto& call, auto result) {
+    if (call.method_name() == "setTitleBarDarkMode") {
+      const auto* arguments = std::get_if<flutter::EncodableMap>(call.arguments());
+      if (arguments) {
+        auto is_dark_it = arguments->find(flutter::EncodableValue("isDark"));
+        if (is_dark_it != arguments->end()) {
+          bool is_dark = std::get<bool>(is_dark_it->second);
+          Win32Window::SetDarkMode(is_dark ? TRUE : FALSE);
+          Win32Window::UpdateTheme(GetHandle());
+          result->Success();
+        } else {
+          result->Error("InvalidArguments", "Missing 'isDark' argument");
+        }
+      } else {
+        result->Error("InvalidArguments", "Arguments are not a map");
+      }
+    } else if (call.method_name() == "resetTitleBarTheme") {
+      // Reset to follow system theme
+      Win32Window::SetDarkMode(-1);
+      Win32Window::UpdateTheme(GetHandle());
+      result->Success();
+    } else {
+      result->NotImplemented();
+    }
+  });
+}
diff --git a/windows/runner/flutter_window.h b/windows/runner/flutter_window.h
index f523a885e..3cd548ced 100644
--- a/windows/runner/flutter_window.h
+++ b/windows/runner/flutter_window.h
@@ -37,6 +37,9 @@ class FlutterWindow : public Win32Window {
 
   // Register Shortcut MethodChannel
   void RegisterShortcutChannel();
+
+  // Register Theme MethodChannel for immersive title bar
+  void RegisterThemeChannel();
 };
 
 #endif  // RUNNER_FLUTTER_WINDOW_H_
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 8e098faba..824058561 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -55,6 +55,9 @@ void EnableFullDpiSupportIfAvailable(HWND hwnd) {
 
 }  // namespace
 
+// Static member definition - must be outside anonymous namespace
+BOOL Win32Window::manual_dark_mode_ = -1;
+
 // Manages the Win32Window's window class registration.
 class WindowClassRegistrar {
  public:
@@ -280,17 +283,36 @@ void Win32Window::OnDestroy() {
   // No-op; provided for subclasses.
 }
 
-void Win32Window::UpdateTheme(HWND const window) {
-  DWORD light_mode;
-  DWORD light_mode_size = sizeof(light_mode);
-  LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
-                               kGetPreferredBrightnessRegValue,
-                               RRF_RT_REG_DWORD, nullptr, &light_mode,
-                               &light_mode_size);
-
-  if (result == ERROR_SUCCESS) {
-    BOOL enable_dark_mode = light_mode == 0;
-    DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
-                          &enable_dark_mode, sizeof(enable_dark_mode));
+void Win32Window::UpdateTheme(HWND const window, BOOL dark_mode) {
+  BOOL enable_dark_mode;
+
+  // Use provided dark_mode if specified (not -1), otherwise follow system
+  if (dark_mode != -1) {
+    enable_dark_mode = dark_mode;
+  } else {
+    // Check manual preference first
+    if (manual_dark_mode_ != -1) {
+      enable_dark_mode = manual_dark_mode_;
+    } else {
+      // Fall back to system theme
+      DWORD light_mode;
+      DWORD light_mode_size = sizeof(light_mode);
+      LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
+                                   kGetPreferredBrightnessRegValue,
+                                   RRF_RT_REG_DWORD, nullptr, &light_mode,
+                                   &light_mode_size);
+      if (result == ERROR_SUCCESS) {
+        enable_dark_mode = light_mode == 0;
+      } else {
+        enable_dark_mode = FALSE;
+      }
+    }
   }
+
+  DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
+                        &enable_dark_mode, sizeof(enable_dark_mode));
+}
+
+void Win32Window::SetDarkMode(BOOL dark_mode) {
+  manual_dark_mode_ = dark_mode;
 }
diff --git a/windows/runner/win32_window.h b/windows/runner/win32_window.h
index e901dde68..e956a5c67 100644
--- a/windows/runner/win32_window.h
+++ b/windows/runner/win32_window.h
@@ -55,6 +55,13 @@ class Win32Window {
   // Return a RECT representing the bounds of the current client area.
   RECT GetClientArea();
 
+  // Update the window frame's theme.
+  // If dark_mode is specified, use that value; otherwise follow system theme.
+  static void UpdateTheme(HWND const window, BOOL dark_mode = -1);
+
+  // Set manual dark mode preference and update all windows
+  static void SetDarkMode(BOOL dark_mode);
+
  protected:
   // Processes and route salient window messages for mouse handling,
   // size change and DPI. Delegates handling of these to member overloads that
@@ -87,11 +94,11 @@ class Win32Window {
   // Retrieves a class instance pointer for |window|
   static Win32Window* GetThisFromHandle(HWND const window) noexcept;
 
-  // Update the window frame's theme to match the system theme.
-  static void UpdateTheme(HWND const window);
-
   bool quit_on_close_ = false;
 
+  // Manually specified dark mode preference (-1 = follow system, 0 = light, 1 = dark)
+  static BOOL manual_dark_mode_;
+
   // window handle for top level window.
   HWND window_handle_ = nullptr;
 

From 983d4dd24772d5fd1c0dc85ef6e6e4f9e0c2f078 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 20:54:30 +0800
Subject: [PATCH 02/13] feat: refine Windows title bar theme handling based on
 system settings

---
 lib/app_widget.dart                         | 13 ++++---
 lib/pages/settings/theme_settings_page.dart | 14 +------
 lib/utils/utils.dart                        | 11 ------
 windows/runner/flutter_window.cpp           |  8 +---
 windows/runner/win32_window.cpp             | 41 ++++++---------------
 windows/runner/win32_window.h               | 11 ++----
 6 files changed, 25 insertions(+), 73 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index 97a88d61a..27aa6d9f8 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -216,12 +216,15 @@ class _AppWidgetState extends State<AppWidget>
       themeProvider.setThemeMode(ThemeMode.system, notify: false);
     }
 
-    // Set Windows title bar theme based on app theme
+    // Set Windows title bar theme based on app theme (only when using system title bar)
     if (Platform.isWindows) {
-      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      final isDark = themeProvider.themeMode == ThemeMode.dark ||
-          (themeProvider.themeMode == ThemeMode.system && brightness == Brightness.dark);
-      Utils.setWindowTitleBarDarkMode(isDark);
+      bool showWindowButton = setting.get(SettingBoxKey.showWindowButton, defaultValue: false);
+      if (showWindowButton) {
+        final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+        final isDark = themeProvider.themeMode == ThemeMode.dark ||
+            (themeProvider.themeMode == ThemeMode.system && brightness == Brightness.dark);
+        Utils.setWindowTitleBarDarkMode(isDark);
+      }
     }
 
     themeProvider.setFontFamily(useSystemFont, notify: false);
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index c840adcc3..ab278cd5f 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -123,8 +123,8 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
       defaultThemeMode = theme;
     });
 
-    // Update Windows title bar theme
-    if (Utils.isDesktop() && Platform.isWindows) {
+    // Update Windows title bar theme (only when using system title bar)
+    if (Platform.isWindows && showWindowButton) {
       final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
       final isDark = theme == 'dark' || (theme == 'system' && brightness == Brightness.dark);
       Utils.setWindowTitleBarDarkMode(isDark);
@@ -389,16 +389,6 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
                       showWindowButton = value ?? !showWindowButton;
                       await setting.put(
                           SettingBoxKey.showWindowButton, showWindowButton);
-                      // Reset title bar theme to follow system when hiding system title bar
-                      if (!showWindowButton && Platform.isWindows) {
-                        Utils.resetWindowTitleBarTheme();
-                      } else if (showWindowButton && Platform.isWindows) {
-                        // Update title bar theme based on current app theme when showing system title bar
-                        final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-                        final isDark = defaultThemeMode == 'dark' ||
-                            (defaultThemeMode == 'system' && brightness == Brightness.dark);
-                        Utils.setWindowTitleBarDarkMode(isDark);
-                      }
                       setState(() {});
                     },
                     title: Text('使用系统标题栏',
diff --git a/lib/utils/utils.dart b/lib/utils/utils.dart
index 8c93cab76..5a7920c4b 100644
--- a/lib/utils/utils.dart
+++ b/lib/utils/utils.dart
@@ -711,15 +711,4 @@ class Utils {
       KazumiLogger().e("Failed to set title bar dark mode: '${e.message}'.");
     }
   }
-
-  /// 重置 Windows 标题栏跟随系统主题
-  static Future<void> resetWindowTitleBarTheme() async {
-    if (!Platform.isWindows) return;
-    const MethodChannel themeChannel = MethodChannel("com.predidit.kazumi/theme");
-    try {
-      await themeChannel.invokeMethod("resetTitleBarTheme");
-    } on PlatformException catch (e) {
-      KazumiLogger().e("Failed to reset title bar theme: '${e.message}'.");
-    }
-  }
 }
\ No newline at end of file
diff --git a/windows/runner/flutter_window.cpp b/windows/runner/flutter_window.cpp
index 3815ef065..14fb49f31 100644
--- a/windows/runner/flutter_window.cpp
+++ b/windows/runner/flutter_window.cpp
@@ -193,8 +193,7 @@ void FlutterWindow::RegisterThemeChannel() {
         auto is_dark_it = arguments->find(flutter::EncodableValue("isDark"));
         if (is_dark_it != arguments->end()) {
           bool is_dark = std::get<bool>(is_dark_it->second);
-          Win32Window::SetDarkMode(is_dark ? TRUE : FALSE);
-          Win32Window::UpdateTheme(GetHandle());
+          Win32Window::UpdateTheme(GetHandle(), is_dark);
           result->Success();
         } else {
           result->Error("InvalidArguments", "Missing 'isDark' argument");
@@ -202,11 +201,6 @@ void FlutterWindow::RegisterThemeChannel() {
       } else {
         result->Error("InvalidArguments", "Arguments are not a map");
       }
-    } else if (call.method_name() == "resetTitleBarTheme") {
-      // Reset to follow system theme
-      Win32Window::SetDarkMode(-1);
-      Win32Window::UpdateTheme(GetHandle());
-      result->Success();
     } else {
       result->NotImplemented();
     }
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 824058561..7cd6395f1 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -55,9 +55,6 @@ void EnableFullDpiSupportIfAvailable(HWND hwnd) {
 
 }  // namespace
 
-// Static member definition - must be outside anonymous namespace
-BOOL Win32Window::manual_dark_mode_ = -1;
-
 // Manages the Win32Window's window class registration.
 class WindowClassRegistrar {
  public:
@@ -283,36 +280,20 @@ void Win32Window::OnDestroy() {
   // No-op; provided for subclasses.
 }
 
-void Win32Window::UpdateTheme(HWND const window, BOOL dark_mode) {
+void Win32Window::UpdateTheme(HWND const window, std::optional<bool> dark_mode) {
   BOOL enable_dark_mode;
-
-  // Use provided dark_mode if specified (not -1), otherwise follow system
-  if (dark_mode != -1) {
-    enable_dark_mode = dark_mode;
+  if (dark_mode.has_value()) {
+    enable_dark_mode = dark_mode.value() ? TRUE : FALSE;
   } else {
-    // Check manual preference first
-    if (manual_dark_mode_ != -1) {
-      enable_dark_mode = manual_dark_mode_;
-    } else {
-      // Fall back to system theme
-      DWORD light_mode;
-      DWORD light_mode_size = sizeof(light_mode);
-      LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
-                                   kGetPreferredBrightnessRegValue,
-                                   RRF_RT_REG_DWORD, nullptr, &light_mode,
-                                   &light_mode_size);
-      if (result == ERROR_SUCCESS) {
-        enable_dark_mode = light_mode == 0;
-      } else {
-        enable_dark_mode = FALSE;
-      }
-    }
+    // Follow system theme
+    DWORD light_mode;
+    DWORD light_mode_size = sizeof(light_mode);
+    LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
+                                 kGetPreferredBrightnessRegValue,
+                                 RRF_RT_REG_DWORD, nullptr, &light_mode,
+                                 &light_mode_size);
+    enable_dark_mode = (result == ERROR_SUCCESS && light_mode == 0) ? TRUE : FALSE;
   }
-
   DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
                         &enable_dark_mode, sizeof(enable_dark_mode));
 }
-
-void Win32Window::SetDarkMode(BOOL dark_mode) {
-  manual_dark_mode_ = dark_mode;
-}
diff --git a/windows/runner/win32_window.h b/windows/runner/win32_window.h
index e956a5c67..42c181681 100644
--- a/windows/runner/win32_window.h
+++ b/windows/runner/win32_window.h
@@ -5,6 +5,7 @@
 
 #include <functional>
 #include <memory>
+#include <optional>
 #include <string>
 
 // A class abstraction for a high DPI-aware Win32 Window. Intended to be
@@ -56,11 +57,8 @@ class Win32Window {
   RECT GetClientArea();
 
   // Update the window frame's theme.
-  // If dark_mode is specified, use that value; otherwise follow system theme.
-  static void UpdateTheme(HWND const window, BOOL dark_mode = -1);
-
-  // Set manual dark mode preference and update all windows
-  static void SetDarkMode(BOOL dark_mode);
+  // If dark_mode is specified, use that; otherwise follow system theme.
+  static void UpdateTheme(HWND const window, std::optional<bool> dark_mode = std::nullopt);
 
  protected:
   // Processes and route salient window messages for mouse handling,
@@ -96,9 +94,6 @@ class Win32Window {
 
   bool quit_on_close_ = false;
 
-  // Manually specified dark mode preference (-1 = follow system, 0 = light, 1 = dark)
-  static BOOL manual_dark_mode_;
-
   // window handle for top level window.
   HWND window_handle_ = nullptr;
 

From a51bce95435e27c486604c70e0dc4dd37e4c314b Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 21:46:56 +0800
Subject: [PATCH 03/13] feat: update Windows title bar theme handling and
 method channel setup

---
 lib/app_widget.dart                         |  2 +-
 lib/pages/settings/theme_settings_page.dart |  2 +-
 windows/runner/flutter_window.cpp           | 38 +++++++++++----------
 windows/runner/flutter_window.h             |  2 +-
 windows/runner/win32_window.cpp             | 35 +++++++++++--------
 windows/runner/win32_window.h               |  9 ++---
 6 files changed, 49 insertions(+), 39 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index 27aa6d9f8..b968e226a 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -216,7 +216,7 @@ class _AppWidgetState extends State<AppWidget>
       themeProvider.setThemeMode(ThemeMode.system, notify: false);
     }
 
-    // Set Windows title bar theme based on app theme (only when using system title bar)
+    // Set Windows title bar theme based on app theme
     if (Platform.isWindows) {
       bool showWindowButton = setting.get(SettingBoxKey.showWindowButton, defaultValue: false);
       if (showWindowButton) {
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index ab278cd5f..e4beeea59 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -123,7 +123,7 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
       defaultThemeMode = theme;
     });
 
-    // Update Windows title bar theme (only when using system title bar)
+    // Update Windows title bar theme
     if (Platform.isWindows && showWindowButton) {
       final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
       final isDark = theme == 'dark' || (theme == 'system' && brightness == Brightness.dark);
diff --git a/windows/runner/flutter_window.cpp b/windows/runner/flutter_window.cpp
index 14fb49f31..199313332 100644
--- a/windows/runner/flutter_window.cpp
+++ b/windows/runner/flutter_window.cpp
@@ -180,29 +180,31 @@ void FlutterWindow::RegisterShortcutChannel() {
   });
 }
 
-// Theme MethodChannel setup for immersive title bar
+// Theme MethodChannel setup
 void FlutterWindow::RegisterThemeChannel() {
   auto channel = std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
       flutter_controller_->engine()->messenger(), "com.predidit.kazumi/theme",
       &flutter::StandardMethodCodec::GetInstance());
 
-  channel->SetMethodCallHandler([this](const auto& call, auto result) {
-    if (call.method_name() == "setTitleBarDarkMode") {
-      const auto* arguments = std::get_if<flutter::EncodableMap>(call.arguments());
-      if (arguments) {
-        auto is_dark_it = arguments->find(flutter::EncodableValue("isDark"));
-        if (is_dark_it != arguments->end()) {
-          bool is_dark = std::get<bool>(is_dark_it->second);
-          Win32Window::UpdateTheme(GetHandle(), is_dark);
-          result->Success();
+  channel->SetMethodCallHandler(
+      [this](const flutter::MethodCall<flutter::EncodableValue>& call,
+             std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result) {
+        if (call.method_name() == "setTitleBarDarkMode") {
+          const auto* arguments = std::get_if<flutter::EncodableMap>(call.arguments());
+          if (arguments) {
+            auto is_dark_it = arguments->find(flutter::EncodableValue("isDark"));
+            if (is_dark_it != arguments->end()) {
+              bool is_dark = std::get<bool>(is_dark_it->second);
+              Win32Window::SetTitleBarDarkMode(GetHandle(), is_dark);
+              result->Success();
+            } else {
+              result->Error("InvalidArguments", "Missing 'isDark' argument");
+            }
+          } else {
+            result->Error("InvalidArguments", "Arguments are not a map");
+          }
         } else {
-          result->Error("InvalidArguments", "Missing 'isDark' argument");
+          result->NotImplemented();
         }
-      } else {
-        result->Error("InvalidArguments", "Arguments are not a map");
-      }
-    } else {
-      result->NotImplemented();
-    }
-  });
+      });
 }
diff --git a/windows/runner/flutter_window.h b/windows/runner/flutter_window.h
index 3cd548ced..87fc3b076 100644
--- a/windows/runner/flutter_window.h
+++ b/windows/runner/flutter_window.h
@@ -38,7 +38,7 @@ class FlutterWindow : public Win32Window {
   // Register Shortcut MethodChannel
   void RegisterShortcutChannel();
 
-  // Register Theme MethodChannel for immersive title bar
+  // Register Theme MethodChannel
   void RegisterThemeChannel();
 };
 
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 7cd6395f1..304e0acef 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -221,6 +221,10 @@ Win32Window::MessageHandler(HWND hwnd,
       }
       return 0;
 
+    case WM_SETTINGCHANGE:
+      UpdateTheme(hwnd);
+      return 0;
+
     case WM_DWMCOLORIZATIONCOLORCHANGED:
       UpdateTheme(hwnd);
       return 0;
@@ -280,20 +284,23 @@ void Win32Window::OnDestroy() {
   // No-op; provided for subclasses.
 }
 
-void Win32Window::UpdateTheme(HWND const window, std::optional<bool> dark_mode) {
-  BOOL enable_dark_mode;
-  if (dark_mode.has_value()) {
-    enable_dark_mode = dark_mode.value() ? TRUE : FALSE;
-  } else {
-    // Follow system theme
-    DWORD light_mode;
-    DWORD light_mode_size = sizeof(light_mode);
-    LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
-                                 kGetPreferredBrightnessRegValue,
-                                 RRF_RT_REG_DWORD, nullptr, &light_mode,
-                                 &light_mode_size);
-    enable_dark_mode = (result == ERROR_SUCCESS && light_mode == 0) ? TRUE : FALSE;
+void Win32Window::UpdateTheme(HWND const window) {
+  DWORD light_mode;
+  DWORD light_mode_size = sizeof(light_mode);
+  LSTATUS result = RegGetValue(HKEY_CURRENT_USER, kGetPreferredBrightnessRegKey,
+                               kGetPreferredBrightnessRegValue,
+                               RRF_RT_REG_DWORD, nullptr, &light_mode,
+                               &light_mode_size);
+
+  if (result == ERROR_SUCCESS) {
+    BOOL enable_dark_mode = light_mode == 0;
+    DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
+                          &enable_dark_mode, sizeof(enable_dark_mode));
   }
+}
+
+void Win32Window::SetTitleBarDarkMode(HWND const window, bool dark_mode) {
+  BOOL enable = dark_mode ? TRUE : FALSE;
   DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
-                        &enable_dark_mode, sizeof(enable_dark_mode));
+                        &enable, sizeof(enable));
 }
diff --git a/windows/runner/win32_window.h b/windows/runner/win32_window.h
index 42c181681..64d7d1770 100644
--- a/windows/runner/win32_window.h
+++ b/windows/runner/win32_window.h
@@ -5,7 +5,6 @@
 
 #include <functional>
 #include <memory>
-#include <optional>
 #include <string>
 
 // A class abstraction for a high DPI-aware Win32 Window. Intended to be
@@ -56,9 +55,8 @@ class Win32Window {
   // Return a RECT representing the bounds of the current client area.
   RECT GetClientArea();
 
-  // Update the window frame's theme.
-  // If dark_mode is specified, use that; otherwise follow system theme.
-  static void UpdateTheme(HWND const window, std::optional<bool> dark_mode = std::nullopt);
+  // Set title bar dark mode directly (for app theme sync)
+  static void SetTitleBarDarkMode(HWND const window, bool dark_mode);
 
  protected:
   // Processes and route salient window messages for mouse handling,
@@ -92,6 +90,9 @@ class Win32Window {
   // Retrieves a class instance pointer for |window|
   static Win32Window* GetThisFromHandle(HWND const window) noexcept;
 
+  // Update the window frame's theme to match the system theme.
+  static void UpdateTheme(HWND const window);
+
   bool quit_on_close_ = false;
 
   // window handle for top level window.

From f3b7b3a0de7ad387e0c8faa03b3c4f2377aebd5a Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 21:51:32 +0800
Subject: [PATCH 04/13] feat: simplify theme update handling by removing
 redundant message case and using SetTitleBarDarkMode

---
 windows/runner/win32_window.cpp | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 304e0acef..cac03feb5 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -224,10 +224,6 @@ Win32Window::MessageHandler(HWND hwnd,
     case WM_SETTINGCHANGE:
       UpdateTheme(hwnd);
       return 0;
-
-    case WM_DWMCOLORIZATIONCOLORCHANGED:
-      UpdateTheme(hwnd);
-      return 0;
   }
 
   return DefWindowProc(window_handle_, message, wparam, lparam);
@@ -293,9 +289,7 @@ void Win32Window::UpdateTheme(HWND const window) {
                                &light_mode_size);
 
   if (result == ERROR_SUCCESS) {
-    BOOL enable_dark_mode = light_mode == 0;
-    DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
-                          &enable_dark_mode, sizeof(enable_dark_mode));
+    SetTitleBarDarkMode(window, light_mode == 0);
   }
 }
 

From effaed3f25882109b34f09637a492bc06b19533a Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 22:00:17 +0800
Subject: [PATCH 05/13] feat: enhance Windows title bar theme handling by
 simplifying logic and adding isEffectiveDark method

---
 lib/app_widget.dart                         | 9 ++-------
 lib/bean/settings/theme_provider.dart       | 8 ++++++++
 lib/pages/settings/theme_settings_page.dart | 5 ++---
 windows/runner/win32_window.cpp             | 3 ++-
 4 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index b968e226a..9cab4699a 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -218,13 +218,8 @@ class _AppWidgetState extends State<AppWidget>
 
     // Set Windows title bar theme based on app theme
     if (Platform.isWindows) {
-      bool showWindowButton = setting.get(SettingBoxKey.showWindowButton, defaultValue: false);
-      if (showWindowButton) {
-        final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-        final isDark = themeProvider.themeMode == ThemeMode.dark ||
-            (themeProvider.themeMode == ThemeMode.system && brightness == Brightness.dark);
-        Utils.setWindowTitleBarDarkMode(isDark);
-      }
+      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+      Utils.setWindowTitleBarDarkMode(themeProvider.isEffectiveDark(brightness));
     }
 
     themeProvider.setFontFamily(useSystemFont, notify: false);
diff --git a/lib/bean/settings/theme_provider.dart b/lib/bean/settings/theme_provider.dart
index 70fb8cbc9..0e3eabc8d 100644
--- a/lib/bean/settings/theme_provider.dart
+++ b/lib/bean/settings/theme_provider.dart
@@ -8,6 +8,14 @@ class ThemeProvider extends ChangeNotifier {
   late ThemeData dark;
   String? currentFontFamily = customAppFontFamily;
 
+  /// Returns true if the effective theme is dark mode.
+  /// When themeMode is ThemeMode.system, uses the provided platform brightness.
+  bool isEffectiveDark(Brightness platformBrightness) {
+    if (themeMode == ThemeMode.dark) return true;
+    if (themeMode == ThemeMode.light) return false;
+    return platformBrightness == Brightness.dark;
+  }
+
   void setTheme(ThemeData light, ThemeData dark, {bool notify = true}) {
     this.light = light;
     this.dark = dark;
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index e4beeea59..00294b45e 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -124,10 +124,9 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
     });
 
     // Update Windows title bar theme
-    if (Platform.isWindows && showWindowButton) {
+    if (Platform.isWindows) {
       final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      final isDark = theme == 'dark' || (theme == 'system' && brightness == Brightness.dark);
-      Utils.setWindowTitleBarDarkMode(isDark);
+      Utils.setWindowTitleBarDarkMode(themeProvider.isEffectiveDark(brightness));
     }
   }
 
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index cac03feb5..7d70097d0 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -222,7 +222,8 @@ Win32Window::MessageHandler(HWND hwnd,
       return 0;
 
     case WM_SETTINGCHANGE:
-      UpdateTheme(hwnd);
+      // WM_SETTINGCHANGE is handled by Flutter layer rebuild,
+      // no need to update title bar theme here.
       return 0;
   }
 

From b04b611319639e9c77b32285227707b45fd20e05 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 22:15:49 +0800
Subject: [PATCH 06/13] ref: use windowManager.setBrightness method

---
 lib/app_widget.dart                         |  2 +-
 lib/pages/settings/theme_settings_page.dart |  3 +-
 lib/utils/utils.dart                        | 12 +-------
 windows/runner/flutter_window.cpp           | 31 ---------------------
 windows/runner/flutter_window.h             |  3 --
 windows/runner/win32_window.cpp             | 13 +++------
 windows/runner/win32_window.h               |  3 --
 7 files changed, 8 insertions(+), 59 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index 9cab4699a..cec6738c8 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -219,7 +219,7 @@ class _AppWidgetState extends State<AppWidget>
     // Set Windows title bar theme based on app theme
     if (Platform.isWindows) {
       final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      Utils.setWindowTitleBarDarkMode(themeProvider.isEffectiveDark(brightness));
+      windowManager.setBrightness(themeProvider.isEffectiveDark(brightness) ? Brightness.dark : Brightness.light);
     }
 
     themeProvider.setFontFamily(useSystemFont, notify: false);
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index 00294b45e..ea46b65d2 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -13,6 +13,7 @@ import 'package:kazumi/bean/settings/color_type.dart';
 import 'package:kazumi/utils/utils.dart';
 import 'package:card_settings_ui/card_settings_ui.dart';
 import 'package:provider/provider.dart';
+import 'package:window_manager/window_manager.dart';
 
 class ThemeSettingsPage extends StatefulWidget {
   const ThemeSettingsPage({super.key});
@@ -126,7 +127,7 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
     // Update Windows title bar theme
     if (Platform.isWindows) {
       final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      Utils.setWindowTitleBarDarkMode(themeProvider.isEffectiveDark(brightness));
+      await windowManager.setBrightness(themeProvider.isEffectiveDark(brightness) ? Brightness.dark : Brightness.light);
     }
   }
 
diff --git a/lib/utils/utils.dart b/lib/utils/utils.dart
index 5a7920c4b..2e809f5d4 100644
--- a/lib/utils/utils.dart
+++ b/lib/utils/utils.dart
@@ -701,14 +701,4 @@ class Utils {
     });
   }
 
-  /// 设置 Windows 标题栏深色模式
-  static Future<void> setWindowTitleBarDarkMode(bool isDark) async {
-    if (!Platform.isWindows) return;
-    const MethodChannel themeChannel = MethodChannel("com.predidit.kazumi/theme");
-    try {
-      await themeChannel.invokeMethod("setTitleBarDarkMode", {"isDark": isDark});
-    } on PlatformException catch (e) {
-      KazumiLogger().e("Failed to set title bar dark mode: '${e.message}'.");
-    }
-  }
-}
\ No newline at end of file
+  }
\ No newline at end of file
diff --git a/windows/runner/flutter_window.cpp b/windows/runner/flutter_window.cpp
index 199313332..a61f019b1 100644
--- a/windows/runner/flutter_window.cpp
+++ b/windows/runner/flutter_window.cpp
@@ -54,9 +54,6 @@ bool FlutterWindow::OnCreate() {
   // Register Shortcut MethodChannel
   RegisterShortcutChannel();
 
-  // Register Theme MethodChannel
-  RegisterThemeChannel();
-
   return true;
 }
 
@@ -180,31 +177,3 @@ void FlutterWindow::RegisterShortcutChannel() {
   });
 }
 
-// Theme MethodChannel setup
-void FlutterWindow::RegisterThemeChannel() {
-  auto channel = std::make_unique<flutter::MethodChannel<flutter::EncodableValue>>(
-      flutter_controller_->engine()->messenger(), "com.predidit.kazumi/theme",
-      &flutter::StandardMethodCodec::GetInstance());
-
-  channel->SetMethodCallHandler(
-      [this](const flutter::MethodCall<flutter::EncodableValue>& call,
-             std::unique_ptr<flutter::MethodResult<flutter::EncodableValue>> result) {
-        if (call.method_name() == "setTitleBarDarkMode") {
-          const auto* arguments = std::get_if<flutter::EncodableMap>(call.arguments());
-          if (arguments) {
-            auto is_dark_it = arguments->find(flutter::EncodableValue("isDark"));
-            if (is_dark_it != arguments->end()) {
-              bool is_dark = std::get<bool>(is_dark_it->second);
-              Win32Window::SetTitleBarDarkMode(GetHandle(), is_dark);
-              result->Success();
-            } else {
-              result->Error("InvalidArguments", "Missing 'isDark' argument");
-            }
-          } else {
-            result->Error("InvalidArguments", "Arguments are not a map");
-          }
-        } else {
-          result->NotImplemented();
-        }
-      });
-}
diff --git a/windows/runner/flutter_window.h b/windows/runner/flutter_window.h
index 87fc3b076..f523a885e 100644
--- a/windows/runner/flutter_window.h
+++ b/windows/runner/flutter_window.h
@@ -37,9 +37,6 @@ class FlutterWindow : public Win32Window {
 
   // Register Shortcut MethodChannel
   void RegisterShortcutChannel();
-
-  // Register Theme MethodChannel
-  void RegisterThemeChannel();
 };
 
 #endif  // RUNNER_FLUTTER_WINDOW_H_
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 7d70097d0..d3e34a46b 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -222,8 +222,7 @@ Win32Window::MessageHandler(HWND hwnd,
       return 0;
 
     case WM_SETTINGCHANGE:
-      // WM_SETTINGCHANGE is handled by Flutter layer rebuild,
-      // no need to update title bar theme here.
+      UpdateTheme(window_handle_);
       return 0;
   }
 
@@ -290,12 +289,8 @@ void Win32Window::UpdateTheme(HWND const window) {
                                &light_mode_size);
 
   if (result == ERROR_SUCCESS) {
-    SetTitleBarDarkMode(window, light_mode == 0);
+    BOOL enable = light_mode == 0 ? TRUE : FALSE;
+    DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
+                          &enable, sizeof(enable));
   }
 }
-
-void Win32Window::SetTitleBarDarkMode(HWND const window, bool dark_mode) {
-  BOOL enable = dark_mode ? TRUE : FALSE;
-  DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
-                        &enable, sizeof(enable));
-}
diff --git a/windows/runner/win32_window.h b/windows/runner/win32_window.h
index 64d7d1770..e901dde68 100644
--- a/windows/runner/win32_window.h
+++ b/windows/runner/win32_window.h
@@ -55,9 +55,6 @@ class Win32Window {
   // Return a RECT representing the bounds of the current client area.
   RECT GetClientArea();
 
-  // Set title bar dark mode directly (for app theme sync)
-  static void SetTitleBarDarkMode(HWND const window, bool dark_mode);
-
  protected:
   // Processes and route salient window messages for mouse handling,
   // size change and DPI. Delegates handling of these to member overloads that

From f8f2e4d7e56297cf6a8de3ee546bb0a777852523 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 22:20:22 +0800
Subject: [PATCH 07/13] fix: remove unnecessary newline

---
 lib/utils/utils.dart              | 3 +--
 windows/runner/flutter_window.cpp | 1 -
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/utils/utils.dart b/lib/utils/utils.dart
index 2e809f5d4..1fdd4773b 100644
--- a/lib/utils/utils.dart
+++ b/lib/utils/utils.dart
@@ -700,5 +700,4 @@ class Utils {
       action?.call();
     });
   }
-
-  }
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/windows/runner/flutter_window.cpp b/windows/runner/flutter_window.cpp
index a61f019b1..f16880f9a 100644
--- a/windows/runner/flutter_window.cpp
+++ b/windows/runner/flutter_window.cpp
@@ -176,4 +176,3 @@ void FlutterWindow::RegisterShortcutChannel() {
     }
   });
 }
-

From 962f1e93f12d5d74ca712b9d931b883c1a2bb6c1 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 22:45:19 +0800
Subject: [PATCH 08/13] imp by review

---
 lib/app_widget.dart                         | 3 +--
 lib/bean/settings/theme_provider.dart       | 6 ++++--
 lib/pages/settings/theme_settings_page.dart | 3 +--
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index cec6738c8..da8262e1f 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -218,8 +218,7 @@ class _AppWidgetState extends State<AppWidget>
 
     // Set Windows title bar theme based on app theme
     if (Platform.isWindows) {
-      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      windowManager.setBrightness(themeProvider.isEffectiveDark(brightness) ? Brightness.dark : Brightness.light);
+      windowManager.setBrightness(themeProvider.isEffectiveDark() ? Brightness.dark : Brightness.light);
     }
 
     themeProvider.setFontFamily(useSystemFont, notify: false);
diff --git a/lib/bean/settings/theme_provider.dart b/lib/bean/settings/theme_provider.dart
index 0e3eabc8d..797739475 100644
--- a/lib/bean/settings/theme_provider.dart
+++ b/lib/bean/settings/theme_provider.dart
@@ -1,4 +1,5 @@
 import 'package:flutter/material.dart';
+import 'package:flutter/scheduler.dart';
 import 'package:kazumi/utils/constants.dart';
 
 class ThemeProvider extends ChangeNotifier {
@@ -9,10 +10,11 @@ class ThemeProvider extends ChangeNotifier {
   String? currentFontFamily = customAppFontFamily;
 
   /// Returns true if the effective theme is dark mode.
-  /// When themeMode is ThemeMode.system, uses the provided platform brightness.
-  bool isEffectiveDark(Brightness platformBrightness) {
+  /// Automatically gets platform brightness when themeMode is ThemeMode.system.
+  bool isEffectiveDark() {
     if (themeMode == ThemeMode.dark) return true;
     if (themeMode == ThemeMode.light) return false;
+    final platformBrightness = SchedulerBinding.instance.platformDispatcher.platformBrightness;
     return platformBrightness == Brightness.dark;
   }
 
diff --git a/lib/pages/settings/theme_settings_page.dart b/lib/pages/settings/theme_settings_page.dart
index ea46b65d2..35795c899 100644
--- a/lib/pages/settings/theme_settings_page.dart
+++ b/lib/pages/settings/theme_settings_page.dart
@@ -126,8 +126,7 @@ class _ThemeSettingsPageState extends State<ThemeSettingsPage> {
 
     // Update Windows title bar theme
     if (Platform.isWindows) {
-      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
-      await windowManager.setBrightness(themeProvider.isEffectiveDark(brightness) ? Brightness.dark : Brightness.light);
+      await windowManager.setBrightness(themeProvider.isEffectiveDark() ? Brightness.dark : Brightness.light);
     }
   }
 

From fb481b6a88c38c4ae24777266ceaf1a21d75f75b Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Fri, 10 Apr 2026 22:48:22 +0800
Subject: [PATCH 09/13] revert

---
 windows/runner/win32_window.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index d3e34a46b..2c096a21a 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -289,8 +289,8 @@ void Win32Window::UpdateTheme(HWND const window) {
                                &light_mode_size);
 
   if (result == ERROR_SUCCESS) {
-    BOOL enable = light_mode == 0 ? TRUE : FALSE;
+    BOOL enable_dark_mode = light_mode == 0;
     DwmSetWindowAttribute(window, DWMWA_USE_IMMERSIVE_DARK_MODE,
-                          &enable, sizeof(enable));
+                          &enable_dark_mode, sizeof(enable_dark_mode));
   }
 }

From 4a27ec1a527f5ad2d5c3ca877d23b4d4c0106c43 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Sat, 11 Apr 2026 16:46:14 +0800
Subject: [PATCH 10/13] fix: update theme handling in MessageHandler to use
 correct window handle

---
 windows/runner/win32_window.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 2c096a21a..39b0a4836 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -222,7 +222,7 @@ Win32Window::MessageHandler(HWND hwnd,
       return 0;
 
     case WM_SETTINGCHANGE:
-      UpdateTheme(window_handle_);
+      UpdateTheme(hwnd);
       return 0;
   }
 

From 8e87e3e34a4d90d3c853176898709f8c0f8f61d6 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Sat, 11 Apr 2026 18:36:41 +0800
Subject: [PATCH 11/13] feat: update title bar theme handling based on platform
 brightness changes

---
 lib/app_widget.dart             | 15 +++++++++++++++
 windows/runner/win32_window.cpp |  1 -
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index da8262e1f..b4afcb06c 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -164,6 +164,21 @@ class _AppWidgetState extends State<AppWidget>
     }
   }
 
+  @override
+  void didChangePlatformBrightness() async {
+    super.didChangePlatformBrightness();
+    final ThemeProvider themeProvider = Provider.of<ThemeProvider>(context, listen: false);
+    KazumiLogger().i("Platform brightness changed, themeMode: ${themeProvider.themeMode}");
+
+    // Only update title bar theme when following system
+    // If user has forced a specific theme, keep title bar consistent with app content
+    if (themeProvider.themeMode == ThemeMode.system && Platform.isWindows) {
+      final brightness = WidgetsBinding.instance.platformDispatcher.platformBrightness;
+      KazumiLogger().i("Updating title bar brightness: $brightness");
+      await windowManager.setBrightness(brightness);
+    }
+  }
+
   Future<void> _handleTray() async {
     if (Platform.isWindows) {
       await trayManager.setIcon('assets/images/logo/logo_lanczos.ico');
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 39b0a4836..6b8f38a36 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -222,7 +222,6 @@ Win32Window::MessageHandler(HWND hwnd,
       return 0;
 
     case WM_SETTINGCHANGE:
-      UpdateTheme(hwnd);
       return 0;
   }
 

From 791485b8845e79770e02839b9bbb0901284d9316 Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Sat, 11 Apr 2026 22:23:16 +0800
Subject: [PATCH 12/13] imp by review

---
 lib/app_widget.dart             | 2 +-
 windows/runner/win32_window.cpp | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/lib/app_widget.dart b/lib/app_widget.dart
index b4afcb06c..f202e83aa 100644
--- a/lib/app_widget.dart
+++ b/lib/app_widget.dart
@@ -165,7 +165,7 @@ class _AppWidgetState extends State<AppWidget>
   }
 
   @override
-  void didChangePlatformBrightness() async {
+  Future<void> didChangePlatformBrightness() async {
     super.didChangePlatformBrightness();
     final ThemeProvider themeProvider = Provider.of<ThemeProvider>(context, listen: false);
     KazumiLogger().i("Platform brightness changed, themeMode: ${themeProvider.themeMode}");
diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 6b8f38a36..33c13cfaa 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -221,8 +221,13 @@ Win32Window::MessageHandler(HWND hwnd,
       }
       return 0;
 
-    case WM_SETTINGCHANGE:
-      return 0;
+    // Theme state is now maintained by Flutter side (app_widget.dart).
+    // WM_DWMCOLORIZATIONCOLORCHANGED is no longer needed because:
+    // - Title bar theme is controlled via windowManager.setBrightness() from Flutter
+    // - didChangePlatformBrightness() handles system theme changes with themeMode awareness
+    // case WM_DWMCOLORIZATIONCOLORCHANGED:
+    //   UpdateTheme(hwnd);
+    //   return 0;
   }
 
   return DefWindowProc(window_handle_, message, wparam, lparam);

From 11a7402033af63937b92c93da4c4186fbd708eff Mon Sep 17 00:00:00 2001
From: WingChunWong <huangrongjun2200@outlook.com>
Date: Sat, 11 Apr 2026 22:25:02 +0800
Subject: [PATCH 13/13] remove llm slop

---
 windows/runner/win32_window.cpp | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/windows/runner/win32_window.cpp b/windows/runner/win32_window.cpp
index 33c13cfaa..1217c619d 100644
--- a/windows/runner/win32_window.cpp
+++ b/windows/runner/win32_window.cpp
@@ -222,9 +222,6 @@ Win32Window::MessageHandler(HWND hwnd,
       return 0;
 
     // Theme state is now maintained by Flutter side (app_widget.dart).
-    // WM_DWMCOLORIZATIONCOLORCHANGED is no longer needed because:
-    // - Title bar theme is controlled via windowManager.setBrightness() from Flutter
-    // - didChangePlatformBrightness() handles system theme changes with themeMode awareness
     // case WM_DWMCOLORIZATIONCOLORCHANGED:
     //   UpdateTheme(hwnd);
     //   return 0;