diff --git a/framelesshelper.cpp b/framelesshelper.cpp
index dca059b..e139fa4 100644
--- a/framelesshelper.cpp
+++ b/framelesshelper.cpp
@@ -34,177 +34,67 @@
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
-FramelessHelper::FramelessHelper(QObject *parent) : QObject(parent) {}
-
-void FramelessHelper::removeWindowFrame(QWindow *window)
+FramelessHelper::FramelessHelper(QWindow *window)
+    : QObject(window)
+    , m_window(window)
 {
-    Q_ASSERT(window);
-    if (!window) {
-        return;
-    }
-    window->setFlags(window->flags() | Qt::FramelessWindowHint);
-    window->installEventFilter(this);
-    window->setProperty(Constants::kFramelessModeFlag, true);
+    Q_ASSERT(window != nullptr && window->isTopLevel());
 }
 
-void FramelessHelper::bringBackWindowFrame(QWindow *window)
+/*!
+    Setup the window, make it frameless.
+ */
+void FramelessHelper::install()
 {
-    Q_ASSERT(window);
-    if (!window) {
+    QRect origRect = m_window->geometry();
+
+    resizeWindow(origRect.size());
+}
+
+/*!
+    Restore the window to its original state
+ */
+void FramelessHelper::uninstall()
+{
+    resizeWindow(QSize());
+}
+
+/*!
+    Resize non-client area
+ */
+void FramelessHelper::resizeWindow(const QSize& windowSize)
+{
+    if (windowSize == this->windowSize())
         return;
-    }
-    window->removeEventFilter(this);
-    window->setFlags(window->flags() & ~Qt::FramelessWindowHint);
-    window->setProperty(Constants::kFramelessModeFlag, false);
+
+    setWindowSize(windowSize);
+}
+
+QRect FramelessHelper::titleBarRect()
+{
+    return QRect(0, 0, windowSize().width(), titleBarHeight());
+}
+
+QRect FramelessHelper::clientRect()
+{
+    QRect rect(0, 0, windowSize().width(), windowSize().height());
+    rect = rect.adjusted(
+        resizeBorderThickness(), titleBarHeight(),
+        -resizeBorderThickness(), -resizeBorderThickness()
+    );
+    return rect;
+}
+
+QRegion FramelessHelper::nonClientRegion()
+{
+    QRegion region(QRect(QPoint(0, 0), windowSize()));
+    region -= clientRect();
+    return region;
 }
 
 bool FramelessHelper::eventFilter(QObject *object, QEvent *event)
 {
-    Q_ASSERT(object);
-    Q_ASSERT(event);
-    if (!object || !event) {
-        return false;
-    }
-    // Only monitor window events.
-    if (!object->isWindowType()) {
-        return false;
-    }
-    const QEvent::Type type = event->type();
-    // We are only interested in mouse events.
-    if ((type != QEvent::MouseButtonDblClick) && (type != QEvent::MouseButtonPress)
-            && (type != QEvent::MouseMove)) {
-        return false;
-    }
-    const auto window = qobject_cast<QWindow *>(object);
-    const int resizeBorderThickness = FramelessWindowsManager::getResizeBorderThickness(window);
-    const int titleBarHeight = FramelessWindowsManager::getTitleBarHeight(window);
-    const bool resizable = FramelessWindowsManager::getResizable(window);
-    const int windowWidth = window->width();
-    const auto mouseEvent = static_cast<QMouseEvent *>(event);
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    const QPoint localMousePosition = mouseEvent->position().toPoint();
-#else
-    const QPoint localMousePosition = mouseEvent->windowPos().toPoint();
-#endif
-    const Qt::Edges edges = [window, resizeBorderThickness, windowWidth, &localMousePosition] {
-        const int windowHeight = window->height();
-        if (localMousePosition.y() <= resizeBorderThickness) {
-            if (localMousePosition.x() <= resizeBorderThickness) {
-                return Qt::TopEdge | Qt::LeftEdge;
-            }
-            if (localMousePosition.x() >= (windowWidth - resizeBorderThickness)) {
-                return Qt::TopEdge | Qt::RightEdge;
-            }
-            return Qt::Edges{Qt::TopEdge};
-        }
-        if (localMousePosition.y() >= (windowHeight - resizeBorderThickness)) {
-            if (localMousePosition.x() <= resizeBorderThickness) {
-                return Qt::BottomEdge | Qt::LeftEdge;
-            }
-            if (localMousePosition.x() >= (windowWidth - resizeBorderThickness)) {
-                return Qt::BottomEdge | Qt::RightEdge;
-            }
-            return Qt::Edges{Qt::BottomEdge};
-        }
-        if (localMousePosition.x() <= resizeBorderThickness) {
-            return Qt::Edges{Qt::LeftEdge};
-        }
-        if (localMousePosition.x() >= (windowWidth - resizeBorderThickness)) {
-            return Qt::Edges{Qt::RightEdge};
-        }
-        return Qt::Edges{};
-    } ();
-    const bool hitTestVisible = Utilities::isHitTestVisibleInChrome(window);
-    bool isInTitlebarArea = false;
-    if ((window->windowState() == Qt::WindowMaximized)
-            || (window->windowState() == Qt::WindowFullScreen)) {
-        isInTitlebarArea = (localMousePosition.y() >= 0)
-                && (localMousePosition.y() <= titleBarHeight)
-                && (localMousePosition.x() >= 0)
-                && (localMousePosition.x() <= windowWidth)
-                && !hitTestVisible;
-    }
-    if (window->windowState() == Qt::WindowNoState) {
-        isInTitlebarArea = (localMousePosition.y() > resizeBorderThickness)
-                && (localMousePosition.y() <= titleBarHeight)
-                && (localMousePosition.x() > resizeBorderThickness)
-                && (localMousePosition.x() < (windowWidth - resizeBorderThickness))
-                && !hitTestVisible;
-    }
 
-    // Determine if the mouse click occurred in the title bar
-    static bool titlebarClicked = false;
-    if (type == QEvent::MouseButtonPress) {
-        if (isInTitlebarArea)
-            titlebarClicked = true;
-        else
-            titlebarClicked = false;
-    }
-
-    if (type == QEvent::MouseButtonDblClick) {
-        if (mouseEvent->button() != Qt::MouseButton::LeftButton) {
-            return false;
-        }
-        if (isInTitlebarArea) {
-            if (window->windowState() == Qt::WindowState::WindowFullScreen) {
-                return false;
-            }
-            if (window->windowState() == Qt::WindowState::WindowMaximized) {
-                window->showNormal();
-            } else {
-                window->showMaximized();
-            }
-            window->setCursor(Qt::ArrowCursor);
-        }
-    } else if (type == QEvent::MouseMove) {
-        // Display resize indicators
-        static bool cursorChanged = false;
-        if ((window->windowState() == Qt::WindowState::WindowNoState) && resizable) {
-            if (((edges & Qt::TopEdge) && (edges & Qt::LeftEdge))
-                    || ((edges & Qt::BottomEdge) && (edges & Qt::RightEdge))) {
-                window->setCursor(Qt::SizeFDiagCursor);
-                cursorChanged = true;
-            } else if (((edges & Qt::TopEdge) && (edges & Qt::RightEdge))
-                       || ((edges & Qt::BottomEdge) && (edges & Qt::LeftEdge))) {
-                window->setCursor(Qt::SizeBDiagCursor);
-                cursorChanged = true;
-            } else if ((edges & Qt::TopEdge) || (edges & Qt::BottomEdge)) {
-                window->setCursor(Qt::SizeVerCursor);
-                cursorChanged = true;
-            } else if ((edges & Qt::LeftEdge) || (edges & Qt::RightEdge)) {
-                window->setCursor(Qt::SizeHorCursor);
-                cursorChanged = true;
-            } else {
-                if (cursorChanged) {
-                    window->setCursor(Qt::ArrowCursor);
-                    cursorChanged = false;
-                }
-            }
-        }
-
-        if ((mouseEvent->buttons() & Qt::LeftButton) && titlebarClicked) {
-            if (edges == Qt::Edges{}) {
-                if (isInTitlebarArea) {
-                    if (!window->startSystemMove()) {
-                        // ### FIXME: TO BE IMPLEMENTED!
-                        qWarning() << "Current OS doesn't support QWindow::startSystemMove().";
-                    }
-                }
-            }
-        }
-
-    } else if (type == QEvent::MouseButtonPress) {
-        if (edges != Qt::Edges{}) {
-            if ((window->windowState() == Qt::WindowState::WindowNoState) && !hitTestVisible && resizable) {
-                if (!window->startSystemResize(edges)) {
-                    // ### FIXME: TO BE IMPLEMENTED!
-                    qWarning() << "Current OS doesn't support QWindow::startSystemResize().";
-                }
-            }
-        }
-    }
-
-    return false;
 }
 
 FRAMELESSHELPER_END_NAMESPACE
diff --git a/framelesshelper.h b/framelesshelper.h
index 5b7dd86..b923f56 100644
--- a/framelesshelper.h
+++ b/framelesshelper.h
@@ -42,14 +42,40 @@ class FRAMELESSHELPER_API FramelessHelper : public QObject
     Q_DISABLE_COPY_MOVE(FramelessHelper)
 
 public:
-    explicit FramelessHelper(QObject *parent = nullptr);
+    explicit FramelessHelper(QWindow *window);
     ~FramelessHelper() override = default;
 
-    void removeWindowFrame(QWindow *window);
-    void bringBackWindowFrame(QWindow *window);
+    void install();
+    void uninstall();
+
+    QWindow *window() { return m_window; }
+
+    QSize windowSize() { return m_windowSize; }
+    void setWindowSize(const QSize& size) { m_windowSize = size; }
+    void resizeWindow(const QSize& windowSize);
+
+    int titleBarHeight() { return m_titleBarHeight; }
+    int setTitleBarHeight(int height) { m_titleBarHeight = height; }
+    QRect titleBarRect();
+
+    int resizeBorderThickness() { return m_resizeBorderThickness; }
+    void setResizeBorderThickness(int thickness) { m_resizeBorderThickness = thickness; }
+
+    bool resizable() { return m_resizable; }
+    void setResizable(bool resizable) { m_resizable = resizable; }
+
+    QRect clientRect();
+    QRegion nonClientRegion();
 
 protected:
     bool eventFilter(QObject *object, QEvent *event) override;
+
+private:
+    QWindow *m_window;
+    QSize m_windowSize;
+    int m_titleBarHeight;
+    int m_resizeBorderThickness;
+    bool m_resizable;
 };
 
 FRAMELESSHELPER_END_NAMESPACE