Bug 576613 - [win32][DarkTheme] Support Windows 11

This is how Dark Theme's dark scrollbars developed so far:
444560 - initial implementation
562043 - reworked to better approach, but due to using undocumented
         Windows APIs, this needs to ensure (for safety) that
         undocumented APIs are still there. This patch also makes
         popup menus dark.
568108 - added support for undocumented APIs in Win10 21H1 preview
this   - adds support for undocumented APIs in Win11

The goal of this patch is to keep dark menus/scrollbars working in
Win11. Hopefully one day Windows will have public APIs for dark theme.

Change-Id: Idc0fff6e0a6a0a33c506619b836f833590878bfe
Signed-off-by: Alexandr Miloslavskiy <alexandr.miloslavskiy@syntevo.com>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.swt/+/186454
Tested-by: Platform Bot <platform-bot@eclipse.org>
Tested-by: Niraj Modi <niraj.modi@in.ibm.com>
Reviewed-by: Niraj Modi <niraj.modi@in.ibm.com>

Author: SyntevoAlex

bundles/org.eclipse.swt/Eclipse SWT PI/win32/library/os_custom.c

@@ -58,15 +58,15 @@ BOOL Validate_AllowDarkModeForWindow(const BYTE* functionPtr)
 
 #ifdef _M_X64
 	/* Win10 builds from 20236 */
-	if ((functionPtr[0x52] == 0xBA) &&						// mov     edx,
-	    (*(const DWORD*)(functionPtr + 0x53) == 0xA91E))	//             0A91Eh
+	if ((functionPtr[0x52] == 0xBA) &&                      // mov     edx,
+	    (*(const DWORD*)(functionPtr + 0x53) == 0xA91E))    //             0A91Eh
 	{
 		return TRUE;
 	}
 
 	/* Win10 builds from 17763 to 19041 */
-	if ((functionPtr[0x15] == 0xBA) &&						// mov     edx,
-	    (*(const DWORD*)(functionPtr + 0x16) == 0xA91E))	//             0A91Eh
+	if ((functionPtr[0x15] == 0xBA) &&                      // mov     edx,
+	    (*(const DWORD*)(functionPtr + 0x16) == 0xA91E))    //             0A91Eh
 	{
 		return TRUE;
 	}
@@ -102,27 +102,86 @@ TYPE_AllowDarkModeForWindow Locate_AllowDarkModeForWindow()
 	return (TYPE_AllowDarkModeForWindow)candidate;
 }
 
+BOOL Validate_AllowDarkModeForWindowWithTelemetryId(const BYTE* functionPtr)
+{
+#ifdef _M_X64
+	/* This function is rather long, but it uses an ATOM value of 0xA91E which is unlikely to change */
+
+	/* Win10 builds from 21301 */
+	if ((functionPtr[0x31] == 0xBA) &&                      // mov      edx,
+		(*(const DWORD*)(functionPtr + 0x32) == 0xA91E))    //              0A91Eh
+	{
+		return TRUE;
+	}
+
+	return FALSE;
+#else
+	#error Unsupported processor type
+#endif
+}
+
+typedef BOOL (WINAPI* TYPE_AllowDarkModeForWindowWithTelemetryId)(HWND a_HWND, BOOL a_Allow, int a_TelemetryID);
+TYPE_AllowDarkModeForWindowWithTelemetryId Locate_AllowDarkModeForWindowWithTelemetryId()
+{
+	const HMODULE hUxtheme = GetModuleHandle(L"uxtheme.dll");
+	if (!hUxtheme)
+		return 0;
+
+	/*
+	 * Function is only exported by ordinal.
+	 * Hopefully one day Microsoft will finally export it by name.
+	 */
+	const BYTE* candidate = (const BYTE*)GetProcAddress(hUxtheme, MAKEINTRESOURCEA(140));
+	if (!candidate)
+		return 0;
+
+	/*
+	 * In next Windows version, some other function can end up having this ordinal.
+	 * Compare function's code to known signature to make sure.
+	 */
+	if (!Validate_AllowDarkModeForWindowWithTelemetryId(candidate))
+		return 0;
+
+	return (TYPE_AllowDarkModeForWindowWithTelemetryId)candidate;
+}
+
 #ifndef NO_AllowDarkModeForWindow
 JNIEXPORT jboolean JNICALL OS_NATIVE(AllowDarkModeForWindow)
 (JNIEnv* env, jclass that, jlong arg0, jboolean arg1)
 {
 	/* Cache the search result for performance reasons */
 	static TYPE_AllowDarkModeForWindow fn_AllowDarkModeForWindow = 0;
+	static TYPE_AllowDarkModeForWindowWithTelemetryId fn_AllowDarkModeForWindowWithTelemetryId = 0;
 	static int isInitialized = 0;
 	if (!isInitialized)
 	{
 		fn_AllowDarkModeForWindow = Locate_AllowDarkModeForWindow();
+		fn_AllowDarkModeForWindowWithTelemetryId = Locate_AllowDarkModeForWindowWithTelemetryId();
 		isInitialized = 1;
 	}
 
-	if (!fn_AllowDarkModeForWindow)
-		return 0;
+	if (fn_AllowDarkModeForWindow)
+	{
+		jboolean rc = 0;
+		OS_NATIVE_ENTER(env, that, AllowDarkModeForWindow_FUNC);
+		rc = (jboolean)fn_AllowDarkModeForWindow((HWND)arg0, arg1);
+		OS_NATIVE_EXIT(env, that, AllowDarkModeForWindow_FUNC);
+		return rc;
+	}
 
-	jboolean rc = 0;
-	OS_NATIVE_ENTER(env, that, AllowDarkModeForWindow_FUNC);
-	rc = (jboolean)fn_AllowDarkModeForWindow((HWND)arg0, arg1);
-	OS_NATIVE_EXIT(env, that, AllowDarkModeForWindow_FUNC);
-	return rc;
+	// In Win11, 'AllowDarkModeForWindow' is a thin wrapper for 'AllowDarkModeForWindowWithTelemetryId'.
+	// It's hard to verify the wrapper, but it's easy enough to verify the target.
+	// For this reason, call 'AllowDarkModeForWindowWithTelemetryId' here.
+	if (fn_AllowDarkModeForWindowWithTelemetryId)
+	{
+		jboolean rc = 0;
+		OS_NATIVE_ENTER(env, that, AllowDarkModeForWindow_FUNC);
+		rc = (jboolean)fn_AllowDarkModeForWindowWithTelemetryId((HWND)arg0, arg1, 0);
+		OS_NATIVE_EXIT(env, that, AllowDarkModeForWindow_FUNC);
+		return rc;
+	}
+
+	return 0;
 }
 #endif
 
@@ -139,9 +198,9 @@ BOOL Validate_SetPreferredAppMode(const BYTE* functionPtr)
 		return FALSE;
 
 	return
-		(functionPtr[0x00] == 0x8B) && (functionPtr[0x01] == 0x05) &&	// mov     eax,dword ptr [uxtheme!g_preferredAppMode]
-		(functionPtr[0x06] == 0x87) && (functionPtr[0x07] == 0x0D) &&	// xchg    ecx,dword ptr [uxtheme!g_preferredAppMode]
-		(functionPtr[0x0C] == 0xC3);									// ret
+		(functionPtr[0x00] == 0x8B) && (functionPtr[0x01] == 0x05) &&   // mov     eax,dword ptr [uxtheme!g_preferredAppMode]
+		(functionPtr[0x06] == 0x87) && (functionPtr[0x07] == 0x0D) &&   // xchg    ecx,dword ptr [uxtheme!g_preferredAppMode]
+		(functionPtr[0x0C] == 0xC3);                                    // ret
 #else
 	#error Unsupported processor type
 #endif
@@ -196,6 +255,16 @@ JNIEXPORT jint JNICALL OS_NATIVE(SetPreferredAppMode)
 }
 #endif
 
+jboolean isDarkThemeAvailable() {
+    if (!Locate_SetPreferredAppMode())
+        return JNI_FALSE;
+
+    if (!Locate_AllowDarkModeForWindow() && !Locate_AllowDarkModeForWindowWithTelemetryId())
+        return JNI_FALSE;
+
+    return JNI_TRUE;
+}
+
 #ifndef NO_IsDarkModeAvailable
 JNIEXPORT jboolean JNICALL OS_NATIVE(IsDarkModeAvailable)
 (JNIEnv* env, jclass that)
@@ -205,7 +274,7 @@ JNIEXPORT jboolean JNICALL OS_NATIVE(IsDarkModeAvailable)
 	static int isInitialized = 0;
 	if (!isInitialized)
 	{
-		isAvailable = (Locate_SetPreferredAppMode() && Locate_AllowDarkModeForWindow());
+		isAvailable = isDarkThemeAvailable();
 		isInitialized = 1;
 	}