feat: add Windows title bar theme support

src-tauri/src/lib.rs

@@ -3792,6 +3792,7 @@ pub fn run() {
             install_cli,
             uninstall_cli,
             get_cli_status,
+            set_title_bar_theme,
         ])
         .build(tauri::generate_context!())
         .expect("error while building tauri application");
@@ -3814,3 +3815,89 @@ pub fn run() {
         }
     });
 }
+
+#[cfg(target_os = "windows")]
+mod windows_title_bar {
+    use tauri::WebviewWindow;
+
+    #[allow(non_snake_case)]
+    mod dwm {
+        pub const DWMWA_USE_IMMERSIVE_DARK_MODE: u32 = 20;
+        pub const DWMWA_CAPTION_COLOR: u32 = 35;
+        pub const DWMWA_BORDER_COLOR: u32 = 34;
+
+        extern "system" {
+            pub fn DwmSetWindowAttribute(
+                hwnd: isize,
+                attr: u32,
+                value: *const std::ffi::c_void,
+                size: u32,
+            ) -> i32;
+        }
+    }
+
+    pub fn apply_title_bar_theme(window: &WebviewWindow, is_dark: bool) {
+        let Ok(hwnd) = window.hwnd() else {
+            return;
+        };
+        let hwnd = hwnd.0 as isize;
+
+        unsafe {
+            let set_attr =
+                |attr: u32, value: *const std::ffi::c_void, size: u32| {
+                    let _ = dwm::DwmSetWindowAttribute(hwnd, attr, value, size);
+                };
+
+            let dark_mode: i32 = if is_dark { 1 } else { 0 };
+            set_attr(
+                dwm::DWMWA_USE_IMMERSIVE_DARK_MODE,
+                &dark_mode as *const _ as *const std::ffi::c_void,
+                std::mem::size_of::<i32>() as u32,
+            );
+
+            if is_dark {
+                let caption_color: u32 = 0x00_0E_0C_0B;
+                set_attr(
+                    dwm::DWMWA_CAPTION_COLOR,
+                    &caption_color as *const _ as *const std::ffi::c_void,
+                    std::mem::size_of::<u32>() as u32,
+                );
+                set_attr(
+                    dwm::DWMWA_BORDER_COLOR,
+                    &caption_color as *const _ as *const std::ffi::c_void,
+                    std::mem::size_of::<u32>() as u32,
+                );
+            } else {
+                let caption_color: u32 = 0x00_FA_FA_F9;
+                set_attr(
+                    dwm::DWMWA_CAPTION_COLOR,
+                    &caption_color as *const _ as *const std::ffi::c_void,
+                    std::mem::size_of::<u32>() as u32,
+                );
+                set_attr(
+                    dwm::DWMWA_BORDER_COLOR,
+                    &caption_color as *const _ as *const std::ffi::c_void,
+                    std::mem::size_of::<u32>() as u32,
+                );
+            }
+        }
+    }
+}
+
+#[tauri::command]
+fn set_title_bar_theme(app: AppHandle, is_dark: bool) -> Result<(), String> {
+    #[cfg(target_os = "windows")]
+    {
+        for (label, window) in app.webview_windows() {
+            if label == "main" || label.starts_with("preview-") {
+                windows_title_bar::apply_title_bar_theme(&window, is_dark);
+            }
+        }
+    }
+    #[cfg(not(target_os = "windows"))]
+    {
+        let _ = app;
+        let _ = is_dark;
+    }
+    Ok(())
+}

src/context/ThemeContext.tsx

@@ -6,6 +6,7 @@ import {
   useCallback,
   type ReactNode,
 } from "react";
+import { invoke } from "@tauri-apps/api/core";
 import { getSettings, updateSettings } from "../services/notes";
 import type {
   ThemeSettings,
@@ -270,6 +271,10 @@ export function ThemeProvider({ children }: ThemeProviderProps) {
     } else {
       root.classList.remove("dark");
     }
+
+    invoke("set_title_bar_theme", { isDark: resolvedTheme === "dark" }).catch(
+      () => {},
+    );
   }, [resolvedTheme]);
 
   // Save theme mode to backend