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#ifndef QWINDOWSSCALING_H
#define QWINDOWSSCALING_H

#include <QtGui/QRegion>
#include <QtCore/QVector>
#include <QtCore/QRect>

QT_BEGIN_NAMESPACE

enum
#if defined(Q_COMPILER_CLASS_ENUM) || defined(Q_CC_MSVC)
     : int
#endif
{ QWINDOWSIZE_MAX = 16777215 };

class QWindowsScaling {
public:
    static bool isActive() { return m_factor > 1; }
    static int factor()  { return m_factor; }
    static void setFactor(int factor) { m_factor = factor; }
    static int determineUiScaleFactor();

    // Scaling helpers for size constraints.
    static int mapToNativeConstrained(int qt)
        { return m_factor != 1 && qt > 0 && qt < QWINDOWSIZE_MAX ? qt * m_factor : qt; }

    static int mapFromNativeConstrained(int dp)
        { return m_factor != 1 && dp > 0 && dp < QWINDOWSIZE_MAX ? dp / m_factor : dp; }

    static QSize mapToNativeConstrained(const QSize &qt)
        { return QSize(mapToNativeConstrained(qt.width()), mapToNativeConstrained(qt.height())); }

    static QRect mapToNative(const QRect &qRect)
    {
        return QRect(qRect.x() * m_factor, qRect.y() * m_factor, qRect.width() * m_factor, qRect.height() * m_factor);
    }

    static QRect mapFromNative(const QRect &dp)
    {
        return isActive() ?
            QRect(dp.x() / m_factor, dp.y() / m_factor, (dp.width() + 1) / m_factor, (dp.height() + 1) / m_factor) :
            dp;
    }

    static QRegion mapToNative(const QRegion &regionQt)
    {
        if (!QWindowsScaling::isActive() || regionQt.isEmpty())
            return regionQt;

        QRegion result;
        foreach (const QRect &rectQt, regionQt.rects())
            result += QWindowsScaling::mapToNative(rectQt);
        return result;
    }

    static QRegion mapFromNative(const QRegion &regionDp)
    {
        if (!QWindowsScaling::isActive() || regionDp.isEmpty())
            return regionDp;

        QRegion result;
        foreach (const QRect &rectDp, regionDp.rects())
            result += QWindowsScaling::mapFromNative(rectDp);
        return result;
    }

private:
    static int m_factor;
};

QT_END_NAMESPACE

#endif // QWINDOWSSCALING_H