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#include  "qwindowsscaling.h"
#include  "qwindowsscreen.h"

#include <QtCore/QDebug>
#include <QtCore/QCoreApplication>

QT_BEGIN_NAMESPACE

/*!
    \class QWindowsScaling
    \brief Windows scaling utilities

    \internal
    \ingroup qt-lighthouse-win
*/

int QWindowsScaling::m_factor = 1;

static const char devicePixelRatioEnvVar[] = "QT_DEVICE_PIXEL_RATIO";

// Suggest a scale factor by checking monitor sizes.
int QWindowsScaling::determineUiScaleFactor()
{
    if (!qEnvironmentVariableIsSet(devicePixelRatioEnvVar))
        return 1;
    const QByteArray envDevicePixelRatioEnv = qgetenv(devicePixelRatioEnvVar);
    // Auto: Suggest a scale factor by checking monitor resolution.
    if (envDevicePixelRatioEnv == "auto") {
        const int maxResolution = QWindowsScreen::maxMonitorHorizResolution();
        return maxResolution > 180 ? maxResolution / 96 : 1;
    }
    // Get factor from environment
    bool ok = false;
    const int envFactor = envDevicePixelRatioEnv.toInt(&ok);
    return ok && envFactor > 0 ? envFactor : 1;
}

QT_END_NAMESPACE