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#include "aspectratiolabel.h"

using namespace QInstaller;

/*!
    \class QInstaller::AspectRatioLabel
    \inmodule QtInstallerFramework
    \brief The AspectRatioLabel class provides a label for displaying
        a pixmap that maintains its original aspect ratio when resized.
*/

/*!
    Constructs the label with \a parent as parent.
*/
AspectRatioLabel::AspectRatioLabel(QWidget *parent)
    : QLabel(parent)
{
    setMinimumSize(1, 1);
    setScaledContents(false);
}

/*!
    Sets the \a pixmap shown on the label. Setting a new pixmap clears the previous content.
*/
void AspectRatioLabel::setPixmap(const QPixmap &pixmap)
{
    m_pixmap = pixmap;
    QLabel::setPixmap(scaledPixmap());
}

/*!
    \reimp
*/
int AspectRatioLabel::heightForWidth(int w) const
{
    return m_pixmap.isNull()
        ? height()
        : m_pixmap.height() * w / m_pixmap.width();
}

/*!
    \reimp
*/
QSize AspectRatioLabel::sizeHint() const
{
    const int w = width();
    return QSize(w, heightForWidth(w));
}

/*!
    Returns the currently set pixmap scaled to the label size,
    while preserving the original aspect ratio.
*/
QPixmap AspectRatioLabel::scaledPixmap() const
{
    if (m_pixmap.isNull())
        return QPixmap();

    return m_pixmap.scaled(size() * m_pixmap.devicePixelRatio(),
        Qt::KeepAspectRatio, Qt::SmoothTransformation);
}

/*!
    \reimp
*/
void AspectRatioLabel::resizeEvent(QResizeEvent *event)
{
    Q_UNUSED(event);

    if (!m_pixmap.isNull())
        QLabel::setPixmap(scaledPixmap());
}
