From 14d3920f6a7b199e751cd1bad57499d8e3a96473 Mon Sep 17 00:00:00 2001
From: floppyhammer <tannhauser_chen@outlook.com>
Date: Wed, 22 Feb 2023 14:31:48 +0800
Subject: [PATCH] Add a function to get the system accent color

---
 src/win32_window.c | 40 ++++++++++++++++++++++++++++++++++------
 1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/src/win32_window.c b/src/win32_window.c
index 819dbc90..fcc822c3 100644
--- a/src/win32_window.c
+++ b/src/win32_window.c
@@ -42,8 +42,12 @@
 #define DWMWA_USE_IMMERSIVE_DARK_MODE 20
 #endif
 
-static void applySystemTheme(HWND handle) {
-    if (_glfw.win32.uxtheme.uxThemeAvailable && _glfw.win32.uxtheme.darkTitleAvailable) {
+// Apply the system default theme
+//
+static void applySystemTheme(HWND handle)
+{
+    if (_glfw.win32.uxtheme.uxThemeAvailable && _glfw.win32.uxtheme.darkTitleAvailable)
+    {
         GLFWbool value = _glfw.win32.uxtheme.ShouldAppsUseDarkMode() & 0x1;
         DwmSetWindowAttribute(handle,
                               DWMWA_USE_IMMERSIVE_DARK_MODE,
@@ -52,6 +56,27 @@ static void applySystemTheme(HWND handle) {
     }
 }
 
+static void getAccentColor(float color[4])
+{
+    if (!_glfw.win32.uxtheme.uxThemeAvailable)
+    {
+        return;
+    }
+
+    UINT dwImmersiveColorType = _glfw.win32.uxtheme.GetImmersiveColorTypeFromName(L"ImmersiveSystemAccent");
+    UINT dwImmersiveColorSet = _glfw.win32.uxtheme.GetImmersiveUserColorSetPreference(FALSE, FALSE);
+
+    UINT rgba = _glfw.win32.uxtheme.GetImmersiveColorFromColorSetEx(dwImmersiveColorSet,
+                                                                    dwImmersiveColorType,
+                                                                    FALSE,
+                                                                    0);
+
+    color[0] = (0xFF & rgba);
+    color[1] = ((0xFF00 & rgba) >> 8) ;
+    color[2] = ((0xFF0000 & rgba) >> 16);
+    color[3] = ((0xFF000000 & rgba) >> 24);
+}
+
 // Returns the window style for the specified window
 //
 static DWORD getWindowStyle(const _GLFWwindow* window)
@@ -1458,9 +1483,8 @@ static int createNativeWindow(_GLFWwindow* window,
 
     _glfwGetWindowSizeWin32(window, &window->win32.width, &window->win32.height);
 
-    if (window->theme.variation == GLFW_THEME_DEFAULT) {
-        applySystemTheme(window->win32.handle);
-    }
+    // Use the system default when creating a window
+    applySystemTheme(window->win32.handle);
 
     return GLFW_TRUE;
 }
@@ -2422,10 +2446,14 @@ _GLFWtheme* _glfwGetThemeWin32(_GLFWwindow* window)
     theme->variation = GLFW_THEME_LIGHT;
     theme->flags = 0;
 
-    if (_glfw.win32.uxtheme.uxThemeAvailable && _glfw.win32.uxtheme.darkTitleAvailable) {
+    if (_glfw.win32.uxtheme.uxThemeAvailable && _glfw.win32.uxtheme.darkTitleAvailable)
+    {
         theme->variation = GLFW_THEME_DARK;
     }
 
+    memset(theme->color, 0, sizeof(float) * 4);
+    getAccentColor(theme->color);
+
     return theme;
 }