diff --git a/CMakeLists.txt b/CMakeLists.txt
index 00498be..6871693 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.5)
 
 project(FramelessHelper LANGUAGES CXX)
 
diff --git a/framelesshelper.cpp b/framelesshelper.cpp
index 7985c97..9c78152 100644
--- a/framelesshelper.cpp
+++ b/framelesshelper.cpp
@@ -26,6 +26,7 @@
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
 #include "utilities.h"
+#include "framelesswindowsmanager.h"
 #include <QtCore/qdebug.h>
 #include <QtCore/qcoreevent.h>
 #include <QtGui/qevent.h>
@@ -33,65 +34,26 @@
 
 FramelessHelper::FramelessHelper(QObject *parent) : QObject(parent) {}
 
-int FramelessHelper::getBorderWidth() const
-{
-    return m_borderWidth;
-}
-
-void FramelessHelper::setBorderWidth(const int val)
-{
-    m_borderWidth = val;
-}
-
-int FramelessHelper::getBorderHeight() const
-{
-    return m_borderHeight;
-}
-
-void FramelessHelper::setBorderHeight(const int val)
-{
-    m_borderHeight = val;
-}
-
-int FramelessHelper::getTitleBarHeight() const
-{
-    return m_titleBarHeight;
-}
-
-void FramelessHelper::setTitleBarHeight(const int val)
-{
-    m_titleBarHeight = val;
-}
-
-bool FramelessHelper::getResizable(const QWindow *window) const
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return false;
-    }
-    return !m_fixedSize.value(window);
-}
-
-void FramelessHelper::setResizable(const QWindow *window, const bool val)
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return;
-    }
-    m_fixedSize.insert(window, !val);
-}
-
 void FramelessHelper::removeWindowFrame(QWindow *window)
 {
     Q_ASSERT(window);
     if (!window) {
         return;
     }
-    // TODO: check whether these flags are correct for Linux and macOS.
-    window->setFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowSystemMenuHint
-                     | Qt::WindowMinMaxButtonsHint | Qt::WindowTitleHint);
-    // MouseTracking is always enabled for QWindow.
+    window->setFlags(window->flags() | Qt::FramelessWindowHint);
     window->installEventFilter(this);
+    window->setProperty(_flh_global::_flh_framelessEnabled_flag, true);
+}
+
+void FramelessHelper::bringBackWindowFrame(QWindow *window)
+{
+    Q_ASSERT(window);
+    if (!window) {
+        return;
+    }
+    window->removeEventFilter(this);
+    window->setFlags(window->flags() & ~Qt::FramelessWindowHint);
+    window->setProperty(_flh_global::_flh_framelessEnabled_flag, false);
 }
 
 bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
@@ -104,11 +66,13 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
     if (!object->isWindowType()) {
         return false;
     }
-    // QWindow will always be a top level window. It can't
-    // be anyone's child window.
     const auto currentWindow = qobject_cast<QWindow *>(object);
+    const int m_borderWidth = FramelessWindowsManager::getBorderWidth(currentWindow);
+    const int m_borderHeight = FramelessWindowsManager::getBorderHeight(currentWindow);
+    const int m_titleBarHeight = FramelessWindowsManager::getTitleBarHeight(currentWindow);
+    const bool m_resizable = FramelessWindowsManager::getResizable(currentWindow);
     const auto getWindowEdges =
-        [this](const QPointF &point, const int ww, const int wh) -> Qt::Edges {
+        [m_borderWidth, m_borderHeight](const QPointF &point, const int ww, const int wh) -> Qt::Edges {
         if (point.y() <= m_borderHeight) {
             if (point.x() <= m_borderWidth) {
                 return Qt::Edge::TopEdge | Qt::Edge::LeftEdge;
@@ -152,7 +116,7 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
         }
         return Qt::CursorShape::ArrowCursor;
     };
-    const auto isInTitlebarArea = [this](const QPointF &point, const QWindow *window) -> bool {
+    const auto isInTitlebarArea = [m_titleBarHeight](const QPointF &point, const QWindow *window) -> bool {
         Q_ASSERT(window);
         if (!window) {
             return false;
@@ -160,7 +124,7 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
         return (point.y() <= m_titleBarHeight) && !Utilities::isHitTestVisibleInChrome(window);
     };
     const auto moveOrResize =
-        [this, &getWindowEdges, &isInTitlebarArea](const QPointF &point, QWindow *window) {
+        [m_resizable, &getWindowEdges, &isInTitlebarArea](const QPointF &point, QWindow *window) {
             Q_ASSERT(window);
             if (!window) {
                 return;
@@ -175,7 +139,7 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
                 }
             } else {
                 if ((window->windowState() == Qt::WindowState::WindowNoState)
-                    && !Utilities::isHitTestVisibleInChrome(window) && getResizable(window)) {
+                    && !Utilities::isHitTestVisibleInChrome(window) && m_resizable) {
                     if (!window->startSystemResize(edges)) {
                         // ### FIXME: TO BE IMPLEMENTED!
                         qWarning() << "Current OS doesn't support QWindow::startSystemResize().";
@@ -221,8 +185,7 @@ bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
     } break;
     case QEvent::MouseMove: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
-        if ((currentWindow->windowState() == Qt::WindowState::WindowNoState)
-                && getResizable(currentWindow)) {
+        if ((currentWindow->windowState() == Qt::WindowState::WindowNoState) && m_resizable) {
             currentWindow->setCursor(
                         getCursorShape(getWindowEdges(getMousePos(mouseEvent, false),
                                                       currentWindow->width(),
diff --git a/framelesshelper.h b/framelesshelper.h
index ecb6145..98c28c2 100644
--- a/framelesshelper.h
+++ b/framelesshelper.h
@@ -27,8 +27,7 @@
 #include "framelesshelper_global.h"
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
-#include <QHash>
-#include <QObject>
+#include <QtCore/qobject.h>
 
 QT_BEGIN_NAMESPACE
 QT_FORWARD_DECLARE_CLASS(QWindow)
@@ -44,27 +43,9 @@ public:
     ~FramelessHelper() override = default;
 
     void removeWindowFrame(QWindow *window);
-
-    int getBorderWidth() const;
-    void setBorderWidth(const int val);
-
-    int getBorderHeight() const;
-    void setBorderHeight(const int val);
-
-    int getTitleBarHeight() const;
-    void setTitleBarHeight(const int val);
-
-    bool getResizable(const QWindow *window) const;
-    void setResizable(const QWindow *window, const bool val);
+    void bringBackWindowFrame(QWindow *window);
 
 protected:
     bool eventFilter(QObject *object, QEvent *event) override;
-
-private:
-    // ### FIXME: The default border width and height on Windows is 8 pixels if
-    // the scale factor is 1.0. Don't know how to acquire these values on UNIX
-    // platforms through native API.
-    int m_borderWidth = 8, m_borderHeight = 8, m_titleBarHeight = 30;
-    QHash<const QWindow *, bool> m_fixedSize = {};
 };
 #endif
diff --git a/framelesshelper_global.h b/framelesshelper_global.h
index 0bb78fd..5e79de4 100644
--- a/framelesshelper_global.h
+++ b/framelesshelper_global.h
@@ -67,6 +67,6 @@ namespace _flh_global {
 [[maybe_unused]] const char _flh_useNativeTitleBar_flag[] = "_FRAMELESSHELPER_USE_NATIVE_TITLE_BAR";
 [[maybe_unused]] const char _flh_preserveNativeFrame_flag[] = "_FRAMELESSHELPER_PRESERVE_NATIVE_WINDOW_FRAME";
 [[maybe_unused]] const char _flh_forcePreserveNativeFrame_flag[] = "_FRAMELESSHELPER_FORCE_PRESERVE_NATIVE_WINDOW_FRAME";
-[[maybe_unused]] const char _flh_nativeParent_flag[] = "_FRAMELESSHELPER_NATIVE_PARENT";
+[[maybe_unused]] const char _flh_windowFixedSize_flag[] = "_FRAMELESSHELPER_WINDOW_FIXED_SIZE";
 
 }
diff --git a/framelesshelper_win32.cpp b/framelesshelper_win32.cpp
index 15eb181..16bb5c1 100644
--- a/framelesshelper_win32.cpp
+++ b/framelesshelper_win32.cpp
@@ -116,10 +116,10 @@ static inline void installHelper(QWindow *window, const bool enable)
     if (!window) {
         return;
     }
-    window->setProperty(_flh_global::_flh_framelessEnabled_flag, enable);
     Utilities::updateQtFrameMargins(window, enable);
     Utilities::updateFrameMargins(window, !enable);
     Utilities::triggerFrameChange(window);
+    window->setProperty(_flh_global::_flh_framelessEnabled_flag, enable);
 }
 
 FramelessHelperWin::FramelessHelperWin() = default;
@@ -134,19 +134,13 @@ FramelessHelperWin::~FramelessHelperWin()
 void FramelessHelperWin::addFramelessWindow(QWindow *window)
 {
     Q_ASSERT(window);
+    if (!window) {
+        return;
+    }
     setup();
     installHelper(window, true);
 }
 
-bool FramelessHelperWin::isWindowFrameless(const QWindow *window)
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return false;
-    }
-    return window->property(_flh_global::_flh_framelessEnabled_flag).toBool();
-}
-
 void FramelessHelperWin::removeFramelessWindow(QWindow *window)
 {
     Q_ASSERT(window);
@@ -639,30 +633,3 @@ bool FramelessHelperWin::nativeEventFilter(const QByteArray &eventType, void *me
     }
     return false;
 }
-
-void FramelessHelperWin::setBorderWidth(QWindow *window, const int bw)
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return;
-    }
-    window->setProperty(_flh_global::_flh_borderWidth_flag, bw);
-}
-
-void FramelessHelperWin::setBorderHeight(QWindow *window, const int bh)
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return;
-    }
-    window->setProperty(_flh_global::_flh_borderHeight_flag, bh);
-}
-
-void FramelessHelperWin::setTitleBarHeight(QWindow *window, const int tbh)
-{
-    Q_ASSERT(window);
-    if (!window) {
-        return;
-    }
-    window->setProperty(_flh_global::_flh_titleBarHeight_flag, tbh);
-}
diff --git a/framelesshelper_win32.h b/framelesshelper_win32.h
index 57e4411..540373e 100644
--- a/framelesshelper_win32.h
+++ b/framelesshelper_win32.h
@@ -41,13 +41,8 @@ public:
     ~FramelessHelperWin() override;
 
     static void addFramelessWindow(QWindow *window);
-    static bool isWindowFrameless(const QWindow *window);
     static void removeFramelessWindow(QWindow *window);
 
-    static void setBorderWidth(QWindow *window, const int bw);
-    static void setBorderHeight(QWindow *window, const int bh);
-    static void setTitleBarHeight(QWindow *window, const int tbh);
-
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
     bool nativeEventFilter(const QByteArray &eventType, void *message, qintptr *result) override;
 #else
diff --git a/framelessquickhelper.cpp b/framelessquickhelper.cpp
index b49f1a8..bf3c238 100644
--- a/framelessquickhelper.cpp
+++ b/framelessquickhelper.cpp
@@ -97,6 +97,16 @@ void FramelessQuickHelper::removeWindowFrame()
     FramelessWindowsManager::addWindow(window());
 }
 
+void FramelessQuickHelper::bringBackWindowFrame()
+{
+    FramelessWindowsManager::removeWindow(window());
+}
+
+bool FramelessQuickHelper::isWindowFrameless() const
+{
+    return FramelessWindowsManager::isWindowFrameless(window());
+}
+
 void FramelessQuickHelper::setHitTestVisibleInChrome(QQuickItem *item, const bool visible)
 {
     Q_ASSERT(item);
diff --git a/framelessquickhelper.h b/framelessquickhelper.h
index a5b4c04..6245fe7 100644
--- a/framelessquickhelper.h
+++ b/framelessquickhelper.h
@@ -60,6 +60,8 @@ public:
 
 public Q_SLOTS:
     void removeWindowFrame();
+    void bringBackWindowFrame();
+    bool isWindowFrameless() const;
     void setHitTestVisibleInChrome(QQuickItem *item, const bool visible);
 
 Q_SIGNALS:
diff --git a/framelesswindowsmanager.cpp b/framelesswindowsmanager.cpp
index 3b9987d..ac8c77a 100644
--- a/framelesswindowsmanager.cpp
+++ b/framelesswindowsmanager.cpp
@@ -35,13 +35,11 @@
 #endif
 
 #ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-Q_GLOBAL_STATIC(FramelessHelper, framelessHelper)
+Q_GLOBAL_STATIC(FramelessHelper, framelessHelperUnix)
 #endif
 
 Q_DECLARE_METATYPE(const QObject *)
 
-FramelessWindowsManager::FramelessWindowsManager() = default;
-
 void FramelessWindowsManager::addWindow(QWindow *window)
 {
     Q_ASSERT(window);
@@ -49,7 +47,7 @@ void FramelessWindowsManager::addWindow(QWindow *window)
         return;
     }
 #ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    framelessHelper()->removeWindowFrame(window);
+    framelessHelperUnix()->removeWindowFrame(window);
 #else
     FramelessHelperWin::addFramelessWindow(window);
     // Work-around a Win32 multi-monitor bug.
@@ -60,7 +58,7 @@ void FramelessWindowsManager::addWindow(QWindow *window)
 #endif
 }
 
-void FramelessWindowsManager::setHitTestVisibleInChrome(QWindow *window, QObject *object, const bool value)
+void FramelessWindowsManager::setHitTestVisibleInChrome(QWindow *window, const QObject *object, const bool value)
 {
     Q_ASSERT(window);
     Q_ASSERT(object);
@@ -71,97 +69,86 @@ void FramelessWindowsManager::setHitTestVisibleInChrome(QWindow *window, QObject
         qWarning() << object << "is not a QWidget or QQuickItem.";
         return;
     }
-    const QObject *nativeParent = Utilities::getNativeParent(object);
-    Q_ASSERT(nativeParent);
-    if (!nativeParent) {
-        return;
+    auto objList = qvariant_cast<QObjectList>(window->property(_flh_global::_flh_hitTestVisibleInChrome_flag));
+    if (value) {
+        if (objList.isEmpty() || !objList.contains(object)) {
+            objList.append(const_cast<QObject *>(object));
+        }
+    } else {
+        if (!objList.isEmpty() && objList.contains(object)) {
+            objList.removeAll(object);
+        }
     }
-    window->setProperty(_flh_global::_flh_nativeParent_flag, QVariant::fromValue(nativeParent));
-    object->setProperty(_flh_global::_flh_hitTestVisibleInChrome_flag, value);
+    window->setProperty(_flh_global::_flh_hitTestVisibleInChrome_flag, QVariant::fromValue(objList));
 }
 
 int FramelessWindowsManager::getBorderWidth(const QWindow *window)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    return framelessHelper()->getBorderWidth();
-#else
     Q_ASSERT(window);
     if (!window) {
-        return 0;
+        return 8;
     }
+#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
+    const int value = window->property(_flh_global::_flh_borderWidth_flag).toInt();
+    return value <= 0 ? 8 : value;
+#else
     return Utilities::getSystemMetric(window, Utilities::SystemMetric::BorderWidth, false);
 #endif
 }
 
 void FramelessWindowsManager::setBorderWidth(QWindow *window, const int value)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    framelessHelper()->setBorderWidth(value);
-#else
     Q_ASSERT(window);
-    if (!window) {
+    if (!window || (value <= 0)) {
         return;
     }
-    FramelessHelperWin::setBorderWidth(window, value);
-#endif
+    window->setProperty(_flh_global::_flh_borderWidth_flag, value);
 }
 
 int FramelessWindowsManager::getBorderHeight(const QWindow *window)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    return framelessHelper()->getBorderHeight();
-#else
     Q_ASSERT(window);
     if (!window) {
-        return 0;
+        return 8;
     }
+#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
+    const int value = window->property(_flh_global::_flh_borderHeight_flag).toInt();
+    return value <= 0 ? 8 : value;
+#else
     return Utilities::getSystemMetric(window, Utilities::SystemMetric::BorderHeight, false);
 #endif
 }
 
 void FramelessWindowsManager::setBorderHeight(QWindow *window, const int value)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    framelessHelper()->setBorderHeight(value);
-#else
     Q_ASSERT(window);
-    if (!window) {
+    if (!window || (value <= 0)) {
         return;
     }
-    FramelessHelperWin::setBorderHeight(window, value);
-#endif
+    window->setProperty(_flh_global::_flh_borderHeight_flag, value);
 }
 
 int FramelessWindowsManager::getTitleBarHeight(const QWindow *window)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    return framelessHelper()->getTitleBarHeight();
-#else
     Q_ASSERT(window);
     if (!window) {
-        return 0;
+        return 30;
     }
+#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
+    const int value = window->property(_flh_global::_flh_titleBarHeight_flag).toInt();
+    return value <= 0 ? 30 : value;
+#else
     return Utilities::getSystemMetric(window, Utilities::SystemMetric::TitleBarHeight, false);
 #endif
 }
 
 void FramelessWindowsManager::setTitleBarHeight(QWindow *window, const int value)
 {
-#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    Q_UNUSED(window);
-    framelessHelper()->setTitleBarHeight(value);
-#else
     Q_ASSERT(window);
-    if (!window) {
+    if (!window || (value <= 0)) {
         return;
     }
-    FramelessHelperWin::setTitleBarHeight(window, value);
-#endif
+    window->setProperty(_flh_global::_flh_titleBarHeight_flag, value);
 }
 
 bool FramelessWindowsManager::getResizable(const QWindow *window)
@@ -171,7 +158,7 @@ bool FramelessWindowsManager::getResizable(const QWindow *window)
         return false;
     }
 #ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    return framelessHelper()->getResizable(window);
+    return !window->property(_flh_global::_flh_windowFixedSize_flag).toBool();
 #else
     return !Utilities::isWindowFixedSize(window);
 #endif
@@ -184,8 +171,30 @@ void FramelessWindowsManager::setResizable(QWindow *window, const bool value)
         return;
     }
 #ifdef FRAMELESSHELPER_USE_UNIX_VERSION
-    framelessHelper()->setResizable(window, value);
+    window->setProperty(_flh_global::_flh_windowFixedSize_flag, !value);
 #else
     window->setFlag(Qt::MSWindowsFixedSizeDialogHint, !value);
 #endif
 }
+
+void FramelessWindowsManager::removeWindow(QWindow *window)
+{
+    Q_ASSERT(window);
+    if (!window) {
+        return;
+    }
+#ifdef FRAMELESSHELPER_USE_UNIX_VERSION
+    framelessHelperUnix()->bringBackWindowFrame(window);
+#else
+    FramelessHelperWin::removeFramelessWindow(window);
+#endif
+}
+
+bool FramelessWindowsManager::isWindowFrameless(const QWindow *window)
+{
+    Q_ASSERT(window);
+    if (!window) {
+        return false;
+    }
+    return window->property(_flh_global::_flh_framelessEnabled_flag).toBool();
+}
diff --git a/framelesswindowsmanager.h b/framelesswindowsmanager.h
index b8483c8..7607e15 100644
--- a/framelesswindowsmanager.h
+++ b/framelesswindowsmanager.h
@@ -25,34 +25,25 @@
 #pragma once
 
 #include "framelesshelper_global.h"
-#include <QRect>
 
 QT_BEGIN_NAMESPACE
 QT_FORWARD_DECLARE_CLASS(QObject)
 QT_FORWARD_DECLARE_CLASS(QWindow)
 QT_END_NAMESPACE
 
-class FRAMELESSHELPER_API FramelessWindowsManager
-{
-    Q_DISABLE_COPY_MOVE(FramelessWindowsManager)
+namespace FramelessWindowsManager {
 
-public:
-    explicit FramelessWindowsManager();
-    ~FramelessWindowsManager() = default;
+FRAMELESSHELPER_API void addWindow(QWindow *window);
+FRAMELESSHELPER_API void removeWindow(QWindow *window);
+FRAMELESSHELPER_API bool isWindowFrameless(const QWindow *window);
+FRAMELESSHELPER_API void setHitTestVisibleInChrome(QWindow *window, const QObject *object, const bool value = true);
+FRAMELESSHELPER_API int getBorderWidth(const QWindow *window);
+FRAMELESSHELPER_API void setBorderWidth(QWindow *window, const int value);
+FRAMELESSHELPER_API int getBorderHeight(const QWindow *window);
+FRAMELESSHELPER_API void setBorderHeight(QWindow *window, const int value);
+FRAMELESSHELPER_API int getTitleBarHeight(const QWindow *window);
+FRAMELESSHELPER_API void setTitleBarHeight(QWindow *window, const int value);
+FRAMELESSHELPER_API bool getResizable(const QWindow *window);
+FRAMELESSHELPER_API void setResizable(QWindow *window, const bool value = true);
 
-    static void addWindow(QWindow *window);
-
-    static void setHitTestVisibleInChrome(QWindow *window, QObject *object, const bool value = true);
-
-    static int getBorderWidth(const QWindow *window);
-    static void setBorderWidth(QWindow *window, const int value);
-
-    static int getBorderHeight(const QWindow *window);
-    static void setBorderHeight(QWindow *window, const int value);
-
-    static int getTitleBarHeight(const QWindow *window);
-    static void setTitleBarHeight(QWindow *window, const int value);
-
-    static bool getResizable(const QWindow *window);
-    static void setResizable(QWindow *window, const bool value = true);
-};
+}
diff --git a/utilities.cpp b/utilities.cpp
index 64b47a2..87e19fb 100644
--- a/utilities.cpp
+++ b/utilities.cpp
@@ -73,10 +73,9 @@ bool Utilities::isWindowFixedSize(const QWindow *window)
 QPointF Utilities::getGlobalMousePosition(const QWindow *window)
 {
     if (window) {
-        return (QCursor::pos(window->screen()) * window->devicePixelRatio());
+        return QPointF(QCursor::pos(window->screen()) * window->devicePixelRatio());
     } else {
-        const qreal dpr = 1.0; // TODO
-        return (QCursor::pos() * dpr);
+        return QPointF(QCursor::pos() * qGuiApp->devicePixelRatio());
     }
 }
 
@@ -86,8 +85,7 @@ bool Utilities::isHitTestVisibleInChrome(const QWindow *window)
     if (!window) {
         return false;
     }
-    const auto target = qvariant_cast<const QObject *>(window->property(_flh_global::_flh_nativeParent_flag));
-    const QObjectList objs = target ? target->findChildren<QObject *>() : window->findChildren<QObject *>();
+    const auto objs = qvariant_cast<QObjectList>(window->property(_flh_global::_flh_hitTestVisibleInChrome_flag));
     if (objs.isEmpty()) {
         return false;
     }
@@ -95,7 +93,7 @@ bool Utilities::isHitTestVisibleInChrome(const QWindow *window)
         if (!obj || !(obj->isWidgetType() || obj->inherits("QQuickItem"))) {
             continue;
         }
-        if (!obj->property(_flh_global::_flh_hitTestVisibleInChrome_flag).toBool() || !obj->property("visible").toBool()) {
+        if (!obj->property("visible").toBool()) {
             continue;
         }
         const QPointF originPoint = mapOriginPointToWindow(obj);
@@ -110,27 +108,6 @@ bool Utilities::isHitTestVisibleInChrome(const QWindow *window)
     return false;
 }
 
-QObject *Utilities::getNativeParent(const QObject *object)
-{
-    Q_ASSERT(object);
-    if (!object) {
-        return nullptr;
-    }
-    if (!object->isWidgetType() && !object->inherits("QQuickItem")) {
-        qWarning() << object << "is not a QWidget or a QQuickItem.";
-        return nullptr;
-    }
-    QObject *parent = object->parent();
-    while (parent) {
-        QObject *p = parent->parent();
-        if (!p || p->isWindowType()) {
-            return parent;
-        }
-        parent = p;
-    }
-    return parent;
-}
-
 QPointF Utilities::mapOriginPointToWindow(const QObject *object)
 {
     Q_ASSERT(object);
diff --git a/utilities.h b/utilities.h
index a89543b..81a0c78 100644
--- a/utilities.h
+++ b/utilities.h
@@ -39,24 +39,14 @@ enum class SystemMetric
 
 // Common
 FRAMELESSHELPER_API int getSystemMetric(const QWindow *window, const SystemMetric metric, const bool dpiAware, const bool forceSystemValue = false);
-
 FRAMELESSHELPER_API bool isLightThemeEnabled();
 FRAMELESSHELPER_API bool isDarkThemeEnabled();
-
 FRAMELESSHELPER_API QWindow *findWindow(const WId winId);
-
 FRAMELESSHELPER_API bool shouldUseNativeTitleBar();
-
 FRAMELESSHELPER_API bool isWindowFixedSize(const QWindow *window);
-
 FRAMELESSHELPER_API QPointF getGlobalMousePosition(const QWindow *window);
-
 FRAMELESSHELPER_API bool isHitTestVisibleInChrome(const QWindow *window);
-
 FRAMELESSHELPER_API QColor getNativeWindowFrameColor(const bool isActive = true);
-
-FRAMELESSHELPER_API QObject *getNativeParent(const QObject *object);
-
 FRAMELESSHELPER_API QPointF mapOriginPointToWindow(const QObject *object);
 
 #ifdef Q_OS_WINDOWS
@@ -66,20 +56,15 @@ FRAMELESSHELPER_API bool isWin8OrGreater();
 FRAMELESSHELPER_API bool isWin8Point1OrGreater();
 FRAMELESSHELPER_API bool isWin10OrGreater();
 FRAMELESSHELPER_API bool isWin10OrGreater(const int subVer);
-
 FRAMELESSHELPER_API bool isDwmBlurAvailable();
-
 FRAMELESSHELPER_API bool isColorizationEnabled();
 FRAMELESSHELPER_API QColor getColorizationColor();
-
 FRAMELESSHELPER_API void triggerFrameChange(const QWindow *window);
 FRAMELESSHELPER_API void updateFrameMargins(const QWindow *window, const bool reset);
 FRAMELESSHELPER_API void updateQtFrameMargins(QWindow *window, const bool enable);
-
 FRAMELESSHELPER_API quint32 getWindowDpi(const QWindow *window);
 FRAMELESSHELPER_API QMargins getWindowNativeFrameMargins(const QWindow *window);
-
-FRAMELESSHELPER_API void displaySystemMenu(const QWindow *window, const QPoint &pos = {});
+FRAMELESSHELPER_API void displaySystemMenu(const QWindow *window, const QPointF &pos = {});
 #endif
 
 }
diff --git a/utilities_win32.cpp b/utilities_win32.cpp
index aae902c..a7c51f0 100644
--- a/utilities_win32.cpp
+++ b/utilities_win32.cpp
@@ -284,6 +284,11 @@ void Utilities::triggerFrameChange(const QWindow *window)
 
 void Utilities::updateFrameMargins(const QWindow *window, const bool reset)
 {
+    // DwmExtendFrameIntoClientArea() will always fail if DWM Composition is disabled.
+    // No need to try in this case.
+    if (!isDwmBlurAvailable()) {
+        return;
+    }
     Q_ASSERT(window);
     if (!window) {
         return;
@@ -456,7 +461,7 @@ bool Utilities::isWin10OrGreater(const int subVer)
 #endif
 }
 
-void Utilities::displaySystemMenu(const QWindow *window, const QPoint &pos)
+void Utilities::displaySystemMenu(const QWindow *window, const QPointF &pos)
 {
     Q_ASSERT(window);
     if (!window) {
@@ -511,11 +516,12 @@ void Utilities::displaySystemMenu(const QWindow *window, const QPoint &pos)
         SetMenuItemInfoW(hMenu, SC_MINIMIZE, FALSE, &mii);
     }
     const bool isRtl = QGuiApplication::isRightToLeft();
-    const QPoint point = pos.isNull() ? QCursor::pos(window->screen()) : window->mapToGlobal(pos);
+    const qreal dpr = window->devicePixelRatio();
+    const QPointF point = pos.isNull() ? QPointF(QCursor::pos(window->screen()) * dpr) : QPointF(window->mapToGlobal(pos) * dpr);
     const LPARAM cmd = TrackPopupMenu(hMenu,
             (TPM_LEFTBUTTON | TPM_RIGHTBUTTON | TPM_RETURNCMD | TPM_TOPALIGN |
             (isRtl ? TPM_RIGHTALIGN : TPM_LEFTALIGN)),
-            point.x(), point.y(), 0, hwnd, nullptr);
+            qRound(point.x()), qRound(point.y()), 0, hwnd, nullptr);
     if (cmd) {
         PostMessageW(hwnd, WM_SYSCOMMAND, cmd, 0);
     }