Utility: Implement hasDarkSystray_private on Windows

Fixes: owncloud#7356

src/common/utility_win.cpp

@@ -29,6 +29,8 @@
 
 #include <QLibrary>
 
+#include "common/winrthelper/winrthelper.h"
+
 extern Q_CORE_EXPORT int qt_ntfs_permission_lookup;
 
 static const char systemRunPathC[] = "HKEY_LOCAL_MACHINE\\Software\\Microsoft\\Windows\\CurrentVersion\\Run";
@@ -102,7 +104,7 @@ void setLaunchOnStartup_private(const QString &appName, const QString &guiName,
 
 static inline bool hasDarkSystray_private()
 {
-    return true;
+    return WinRtHelper::hasDarkSystray();
 }
 
 QVariant Utility::registryGetKeyValue(HKEY hRootKey, const QString &subKey, const QString &valueName)

src/common/winrthelper/winrthelper.cpp

@@ -0,0 +1,55 @@
+/*
+ * Copyright (C) by Hannah von Reth <hannah.vonreth@owncloud.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "winrthelper.h"
+
+#include <wrl.h>
+#include <Windows.UI.ViewManagement.h>
+
+#include <algorithm>
+
+namespace  {
+
+ABI::Windows::UI::Color GetThemeColor(ABI::Windows::UI::ViewManagement::UIColorType type, bool *ok)
+{
+    *ok = false;
+    ABI::Windows::UI::Color color;
+    Microsoft::WRL::ComPtr<ABI::Windows::UI::ViewManagement::IUISettings3> settings;
+    if (SUCCEEDED(Windows::Foundation::ActivateInstance(Microsoft::WRL::Wrappers::HStringReference(
+                                                            RuntimeClass_Windows_UI_ViewManagement_UISettings).Get(), &settings)) )
+    {
+        settings->GetColorValue(type, &color);
+        *ok = true;
+    }
+    return color;
+}
+}
+
+namespace WinRtHelper {
+bool hasDarkSystray()
+{
+    bool ok;
+    const auto color = GetThemeColor(ABI::Windows::UI::ViewManagement::UIColorType::UIColorType_Background, &ok);
+    if (ok)
+    {
+        const auto lightness = 0.5 * (std::max(color.R, std::max(color.G, color.B)) + std::min(color.R, std::min(color.G, color.B))) / 255.0;
+        return lightness  < 0.5;
+    }
+    return true;
+}
+}

src/common/winrthelper/winrthelper.h

@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) by Hannah von Reth <hannah.vonreth@owncloud.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef WINRTHELPER_H
+#define WINRTHELPER_H
+
+
+namespace WinRtHelper
+{
+bool hasDarkSystray();
+};
+
+#endif // WINRTHELPER_H

src/csync/CMakeLists.txt

@@ -49,6 +49,15 @@ configure_file(csync_version.h.in ${CMAKE_CURRENT_BINARY_DIR}/csync_version.h)
 
 add_library("${csync_NAME}" SHARED ${common_SOURCES} ${csync_SRCS})
 
+if (WIN32)
+    add_library(ocwinrt STATIC ../common/winrthelper/winrthelper.cpp)
+    set_property(TARGET ocwinrt PROPERTY CXX_STANDARD 17)
+    target_link_libraries(ocwinrt PUBLIC runtimeobject)
+
+    target_link_libraries("${csync_NAME}" ocwinrt)
+endif()
+
+
 target_include_directories(
   "${csync_NAME}"
   PUBLIC ${CMAKE_CURRENT_BINARY_DIR} ${CMAKE_CURRENT_SOURCE_DIR} ${CMAKE_CURRENT_SOURCE_DIR}/std