Dark Mode changes to official API integration

.gitignore

@@ -2,9 +2,12 @@
 _build/
 ARM64/
 Win32/
-x64/
 *.d
 *.o
 *.user
-NppSnippets.dll
 version_git.h
+plugindemo-2025_May_21.10.1/.gitignore
+.claude/settings.local.json
+.claude/todo.txt
+.gitignore
+NppSnippets/

DarkMode.cpp

@@ -0,0 +1,338 @@
+#include <windows.h>
+
+#include "DarkMode.h"
+#include "IatHook.h"
+
+#include <uxtheme.h>
+#include <vssym32.h>
+
+#include <unordered_set>
+#include <mutex>
+
+#if defined(__GNUC__) && __GNUC__ > 8
+#define WINAPI_LAMBDA_RETURN(return_t) -> return_t WINAPI
+#elif defined(__GNUC__)
+#define WINAPI_LAMBDA_RETURN(return_t) WINAPI -> return_t
+#else
+#define WINAPI_LAMBDA_RETURN(return_t) -> return_t
+#endif
+
+enum IMMERSIVE_HC_CACHE_MODE
+{
+	IHCM_USE_CACHED_VALUE,
+	IHCM_REFRESH
+};
+
+// 1903 18362
+enum class PreferredAppMode
+{
+	Default,
+	AllowDark,
+	ForceDark,
+	ForceLight,
+	Max
+};
+
+enum WINDOWCOMPOSITIONATTRIB
+{
+	WCA_UNDEFINED = 0,
+	WCA_NCRENDERING_ENABLED = 1,
+	WCA_NCRENDERING_POLICY = 2,
+	WCA_TRANSITIONS_FORCEDISABLED = 3,
+	WCA_ALLOW_NCPAINT = 4,
+	WCA_CAPTION_BUTTON_BOUNDS = 5,
+	WCA_NONCLIENT_RTL_LAYOUT = 6,
+	WCA_FORCE_ICONIC_REPRESENTATION = 7,
+	WCA_EXTENDED_FRAME_BOUNDS = 8,
+	WCA_HAS_ICONIC_BITMAP = 9,
+	WCA_THEME_ATTRIBUTES = 10,
+	WCA_NCRENDERING_EXILED = 11,
+	WCA_NCADORNMENTINFO = 12,
+	WCA_EXCLUDED_FROM_LIVEPREVIEW = 13,
+	WCA_VIDEO_OVERLAY_ACTIVE = 14,
+	WCA_FORCE_ACTIVEWINDOW_APPEARANCE = 15,
+	WCA_DISALLOW_PEEK = 16,
+	WCA_CLOAK = 17,
+	WCA_CLOAKED = 18,
+	WCA_ACCENT_POLICY = 19,
+	WCA_FREEZE_REPRESENTATION = 20,
+	WCA_EVER_UNCLOAKED = 21,
+	WCA_VISUAL_OWNER = 22,
+	WCA_HOLOGRAPHIC = 23,
+	WCA_EXCLUDED_FROM_DDA = 24,
+	WCA_PASSIVEUPDATEMODE = 25,
+	WCA_USEDARKMODECOLORS = 26,
+	WCA_LAST = 27
+};
+
+struct WINDOWCOMPOSITIONATTRIBDATA
+{
+	WINDOWCOMPOSITIONATTRIB Attrib;
+	PVOID pvData;
+	SIZE_T cbData;
+};
+
+using fnRtlGetNtVersionNumbers = void (WINAPI *)(LPDWORD major, LPDWORD minor, LPDWORD build);
+using fnSetWindowCompositionAttribute = BOOL (WINAPI *)(HWND hWnd, WINDOWCOMPOSITIONATTRIBDATA*);
+using fnShouldAppsUseDarkMode = bool (WINAPI *)(); // ordinal 132
+using fnAllowDarkModeForWindow = bool (WINAPI *)(HWND hWnd, bool allow); // ordinal 133
+using fnAllowDarkModeForApp = bool (WINAPI *)(bool allow); // ordinal 135, in 1809
+using fnFlushMenuThemes = void (WINAPI *)(); // ordinal 136
+using fnRefreshImmersiveColorPolicyState = void (WINAPI *)(); // ordinal 104
+using fnIsDarkModeAllowedForWindow = bool (WINAPI *)(HWND hWnd); // ordinal 137
+using fnGetIsImmersiveColorUsingHighContrast = bool (WINAPI *)(IMMERSIVE_HC_CACHE_MODE mode); // ordinal 106
+using fnOpenNcThemeData = HTHEME(WINAPI *)(HWND hWnd, LPCWSTR pszClassList); // ordinal 49
+using fnSetPreferredAppMode = PreferredAppMode (WINAPI *)(PreferredAppMode appMode); // ordinal 135, in 1903
+
+fnSetWindowCompositionAttribute _SetWindowCompositionAttribute = nullptr;
+fnShouldAppsUseDarkMode _ShouldAppsUseDarkMode = nullptr;
+fnAllowDarkModeForWindow _AllowDarkModeForWindow = nullptr;
+fnAllowDarkModeForApp _AllowDarkModeForApp = nullptr;
+fnFlushMenuThemes _FlushMenuThemes = nullptr;
+fnRefreshImmersiveColorPolicyState _RefreshImmersiveColorPolicyState = nullptr;
+fnIsDarkModeAllowedForWindow _IsDarkModeAllowedForWindow = nullptr;
+fnGetIsImmersiveColorUsingHighContrast _GetIsImmersiveColorUsingHighContrast = nullptr;
+fnOpenNcThemeData _OpenNcThemeData = nullptr;
+fnSetPreferredAppMode _SetPreferredAppMode = nullptr;
+
+bool g_darkModeSupported = false;
+bool g_darkModeEnabled = false;
+DWORD g_buildNumber = 0;
+
+bool ShouldAppsUseDarkMode()
+{
+	if (!_ShouldAppsUseDarkMode)
+	{
+		return false;
+	}
+
+	return _ShouldAppsUseDarkMode();
+}
+
+bool AllowDarkModeForWindow(HWND hWnd, bool allow)
+{
+	if (g_darkModeSupported && _AllowDarkModeForWindow)
+		return _AllowDarkModeForWindow(hWnd, allow);
+	return false;
+}
+
+bool IsHighContrast()
+{
+	HIGHCONTRASTW highContrast{};
+	highContrast.cbSize = sizeof(HIGHCONTRASTW);
+	if (SystemParametersInfoW(SPI_GETHIGHCONTRAST, sizeof(HIGHCONTRASTW), &highContrast, FALSE))
+		return (highContrast.dwFlags & HCF_HIGHCONTRASTON) == HCF_HIGHCONTRASTON;
+	return false;
+}
+
+void SetTitleBarThemeColor(HWND hWnd, BOOL dark)
+{
+	if (g_buildNumber < 18362)
+		SetPropW(hWnd, L"UseImmersiveDarkModeColors", reinterpret_cast<HANDLE>(static_cast<intptr_t>(dark)));
+	else if (_SetWindowCompositionAttribute)
+	{
+		WINDOWCOMPOSITIONATTRIBDATA data = { WCA_USEDARKMODECOLORS, &dark, sizeof(dark) };
+		_SetWindowCompositionAttribute(hWnd, &data);
+	}
+}
+
+void RefreshTitleBarThemeColor(HWND hWnd)
+{
+	BOOL dark = FALSE;
+	if (_IsDarkModeAllowedForWindow && _ShouldAppsUseDarkMode)
+	{
+		if (_IsDarkModeAllowedForWindow(hWnd) && _ShouldAppsUseDarkMode() && !IsHighContrast())
+		{
+			dark = TRUE;
+		}
+	}
+
+	SetTitleBarThemeColor(hWnd, dark);
+}
+
+bool IsColorSchemeChangeMessage(LPARAM lParam)
+{
+	bool is = false;
+	if (lParam && (0 == lstrcmpi(reinterpret_cast<LPCWCH>(lParam), L"ImmersiveColorSet")) && _RefreshImmersiveColorPolicyState)
+	{
+		_RefreshImmersiveColorPolicyState();
+		is = true;
+	}
+	if (_GetIsImmersiveColorUsingHighContrast)
+		_GetIsImmersiveColorUsingHighContrast(IHCM_REFRESH);
+	return is;
+}
+
+bool IsColorSchemeChangeMessage(UINT message, LPARAM lParam)
+{
+	if (message == WM_SETTINGCHANGE)
+		return IsColorSchemeChangeMessage(lParam);
+	return false;
+}
+
+void AllowDarkModeForApp(bool allow)
+{
+	if (_AllowDarkModeForApp)
+		_AllowDarkModeForApp(allow);
+	else if (_SetPreferredAppMode)
+		_SetPreferredAppMode(allow ? PreferredAppMode::ForceDark : PreferredAppMode::Default);
+}
+
+void FlushMenuThemes()
+{
+	if (_FlushMenuThemes)
+	{
+		_FlushMenuThemes();
+	}
+}
+
+// limit dark scroll bar to specific windows and their children
+std::unordered_set<HWND> g_darkScrollBarWindows;
+std::mutex g_darkScrollBarMutex;
+
+void EnableDarkScrollBarForWindowAndChildren(HWND hwnd)
+{
+	std::lock_guard<std::mutex> lock(g_darkScrollBarMutex);
+	g_darkScrollBarWindows.insert(hwnd);
+}
+
+bool IsWindowOrParentUsingDarkScrollBar(HWND hwnd)
+{
+	HWND hwndRoot = GetAncestor(hwnd, GA_ROOT);
+
+	std::lock_guard<std::mutex> lock(g_darkScrollBarMutex);
+	if (g_darkScrollBarWindows.count(hwnd)) {
+		return true;
+	}
+	if (hwnd != hwndRoot && g_darkScrollBarWindows.count(hwndRoot)) {
+		return true;
+	}
+
+	return false;
+}
+
+void FixDarkScrollBar()
+{
+	HMODULE hComctl = LoadLibraryEx(L"comctl32.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
+	if (hComctl)
+	{
+		auto addr = FindDelayLoadThunkInModule(hComctl, "uxtheme.dll", 49); // OpenNcThemeData
+		if (addr)
+		{
+			DWORD oldProtect;
+			if (VirtualProtect(addr, sizeof(IMAGE_THUNK_DATA), PAGE_READWRITE, &oldProtect) && _OpenNcThemeData)
+			{
+				auto MyOpenThemeData = [](HWND hWnd, LPCWSTR classList) WINAPI_LAMBDA_RETURN(HTHEME) {
+					if (wcscmp(classList, L"ScrollBar") == 0)
+					{
+						if (IsWindowOrParentUsingDarkScrollBar(hWnd)) {
+							hWnd = nullptr;
+							classList = L"Explorer::ScrollBar";
+						}
+					}
+					return _OpenNcThemeData(hWnd, classList);
+				};
+
+				addr->u1.Function = reinterpret_cast<ULONG_PTR>(static_cast<fnOpenNcThemeData>(MyOpenThemeData));
+				VirtualProtect(addr, sizeof(IMAGE_THUNK_DATA), oldProtect, &oldProtect);
+			}
+		}
+	}
+}
+
+constexpr bool CheckBuildNumber(DWORD buildNumber)
+{
+	return (buildNumber == 17763 || // 1809
+		buildNumber == 18362 || // 1903
+		buildNumber == 18363 || // 1909
+		buildNumber == 19041 || // 2004
+		buildNumber == 19042 || // 20H2
+		buildNumber == 19043 || // 21H1
+		buildNumber == 19044 || // 21H2
+		(buildNumber > 19044 && buildNumber < 22000) || // Windows 10 any version > 21H2 
+		buildNumber >= 22000);  // Windows 11 builds
+}
+
+bool IsWindows10() // or later OS version
+{
+	return (g_buildNumber >= 17763);
+}
+
+bool IsWindows11() // or later OS version
+{
+	return (g_buildNumber >= 22000);
+}
+
+DWORD GetWindowsBuildNumber()
+{
+	return g_buildNumber;
+}
+
+void InitDarkMode()
+{
+	fnRtlGetNtVersionNumbers RtlGetNtVersionNumbers = nullptr;
+	HMODULE hNtdllModule = GetModuleHandle(L"ntdll.dll");
+	if (hNtdllModule)
+	{
+		RtlGetNtVersionNumbers = reinterpret_cast<fnRtlGetNtVersionNumbers>(GetProcAddress(hNtdllModule, "RtlGetNtVersionNumbers"));
+	}
+
+	if (RtlGetNtVersionNumbers)
+	{
+		DWORD major, minor;
+		RtlGetNtVersionNumbers(&major, &minor, &g_buildNumber);
+		g_buildNumber &= ~0xF0000000;
+		if (major == 10 && minor == 0 && CheckBuildNumber(g_buildNumber))
+		{
+			HMODULE hUxtheme = LoadLibraryEx(L"uxtheme.dll", nullptr, LOAD_LIBRARY_SEARCH_SYSTEM32);
+			if (hUxtheme)
+			{
+				_OpenNcThemeData = reinterpret_cast<fnOpenNcThemeData>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(49)));
+				_RefreshImmersiveColorPolicyState = reinterpret_cast<fnRefreshImmersiveColorPolicyState>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(104)));
+				_GetIsImmersiveColorUsingHighContrast = reinterpret_cast<fnGetIsImmersiveColorUsingHighContrast>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(106)));
+				_ShouldAppsUseDarkMode = reinterpret_cast<fnShouldAppsUseDarkMode>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(132)));
+				_AllowDarkModeForWindow = reinterpret_cast<fnAllowDarkModeForWindow>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(133)));
+
+				auto ord135 = GetProcAddress(hUxtheme, MAKEINTRESOURCEA(135));
+				if (g_buildNumber < 18362)
+					_AllowDarkModeForApp = reinterpret_cast<fnAllowDarkModeForApp>(ord135);
+				else
+					_SetPreferredAppMode = reinterpret_cast<fnSetPreferredAppMode>(ord135);
+
+				_FlushMenuThemes = reinterpret_cast<fnFlushMenuThemes>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(136)));
+				_IsDarkModeAllowedForWindow = reinterpret_cast<fnIsDarkModeAllowedForWindow>(GetProcAddress(hUxtheme, MAKEINTRESOURCEA(137)));
+
+				HMODULE hUser32Module = GetModuleHandleW(L"user32.dll");
+				if (hUser32Module)
+				{
+					_SetWindowCompositionAttribute = reinterpret_cast<fnSetWindowCompositionAttribute>(GetProcAddress(hUser32Module, "SetWindowCompositionAttribute"));
+				}
+
+				if (_OpenNcThemeData &&
+					_RefreshImmersiveColorPolicyState &&
+					_ShouldAppsUseDarkMode &&
+					_AllowDarkModeForWindow &&
+					(_AllowDarkModeForApp || _SetPreferredAppMode) &&
+					_FlushMenuThemes &&
+					_IsDarkModeAllowedForWindow)
+				{
+					g_darkModeSupported = true;
+				}
+			}
+		}
+	}
+}
+
+void SetDarkMode(bool useDark, bool fixDarkScrollbar)
+{
+	if (g_darkModeSupported)
+	{
+		AllowDarkModeForApp(useDark);
+		FlushMenuThemes();
+		if (fixDarkScrollbar)
+		{
+			FixDarkScrollBar();
+		}
+		g_darkModeEnabled = ShouldAppsUseDarkMode() && !IsHighContrast();
+	}
+}

DarkMode.h

@@ -0,0 +1,19 @@
+#pragma once
+
+extern bool g_darkModeSupported;
+extern bool g_darkModeEnabled;
+
+bool ShouldAppsUseDarkMode();
+bool AllowDarkModeForWindow(HWND hWnd, bool allow);
+bool IsHighContrast();
+void RefreshTitleBarThemeColor(HWND hWnd);
+void SetTitleBarThemeColor(HWND hWnd, BOOL dark);
+bool IsColorSchemeChangeMessage(LPARAM lParam);
+bool IsColorSchemeChangeMessage(UINT message, LPARAM lParam);
+void AllowDarkModeForApp(bool allow);
+void EnableDarkScrollBarForWindowAndChildren(HWND hwnd);
+void InitDarkMode();
+void SetDarkMode(bool useDarkMode, bool fixDarkScrollbar);
+bool IsWindows10();
+bool IsWindows11();
+DWORD GetWindowsBuildNumber();