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#include "qquicktableviewextra_p.h"
#include <QtQml>
#include <QQmlContext>
#include <QtQuick/private/qquicktableview_p.h>

Q_LOGGING_CATEGORY(qLcTVE, "qt.pdf.tableextra")

QT_BEGIN_NAMESPACE

/*!
    \internal
    \qmltype TableViewExtra
    \instantiates QQuickTableViewExtra
    \inqmlmodule QtQuick.Pdf
    \ingroup pdf
    \brief A helper class with missing TableView functions
    \since 5.15

    TableViewExtra provides equivalents for some functions that will be added
    to TableView in Qt 6.
*/

QQuickTableViewExtra::QQuickTableViewExtra(QObject *parent) : QObject(parent)
{
}

QPoint QQuickTableViewExtra::cellAtPos(qreal x, qreal y) const
{
    QPointF position(x, y);
#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
    return m_tableView->cellAtPos(position);
#else
    if (!m_tableView->boundingRect().contains(position))
        return QPoint(-1, -1);

    const QQuickItem *contentItem = m_tableView->contentItem();

    for (const QQuickItem *child : contentItem->childItems()) {
        const QPointF posInChild = m_tableView->mapToItem(child, position);
        if (child->boundingRect().contains(posInChild)) {
            const auto context = qmlContext(child);
            const int column = context->contextProperty("column").toInt();
            const int row = context->contextProperty("row").toInt();
            return QPoint(column, row);
        }
    }

    return QPoint(-1, -1);
#endif
}

QQuickItem *QQuickTableViewExtra::itemAtCell(const QPoint &cell) const
{
#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
    return m_tableView->itemAtCell(cell);
#else
    const QQuickItem *contentItem = m_tableView->contentItem();

    for (QQuickItem *child : contentItem->childItems()) {
        const auto context = qmlContext(child);
        const int column = context->contextProperty("column").toInt();
        const int row = context->contextProperty("row").toInt();
        if (QPoint(column, row) == cell)
            return child;
    }

    return nullptr;
#endif
}

void QQuickTableViewExtra::positionViewAtCell(const QPoint &cell, Qt::Alignment alignment, const QPointF &offset)
{
#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
    m_tableView->positionViewAtCell(cell, alignment, offset);
#else
    // Note: this fallback implementation assumes all cells to be of the same size!

    if (cell.x() < 0 || cell.x() > m_tableView->columns() - 1)
        return;
    if (cell.y() < 0 || cell.y() > m_tableView->rows() - 1)
        return;

    Qt::Alignment verticalAlignment = alignment & (Qt::AlignTop | Qt::AlignVCenter | Qt::AlignBottom);
    Qt::Alignment horizontalAlignment = alignment & (Qt::AlignLeft | Qt::AlignHCenter | Qt::AlignRight);

    const QQuickItem *contentItem = m_tableView->contentItem();
    const QQuickItem *randomChild = contentItem->childItems().first();
    const qreal cellWidth = randomChild->width();
    const qreal cellHeight = randomChild->height();

    if (!verticalAlignment && !horizontalAlignment) {
        qmlWarning(this) << "No valid alignment specified";
        return;
    }

    if (horizontalAlignment) {
        qreal newPosX = 0;
        const qreal columnPosLeft = int(cell.x() * (cellWidth + m_tableView->columnSpacing()));
        m_tableView->setContentX(0);
        m_tableView->forceLayout();
        m_tableView->setContentX(columnPosLeft);
        m_tableView->forceLayout();

        switch (horizontalAlignment) {
        case Qt::AlignLeft:
            newPosX = m_tableView->contentX() + offset.x();
            break;
        case Qt::AlignHCenter:
            newPosX = m_tableView->contentX()
                    - m_tableView->width() / 2
                    + (cellWidth / 2)
                    + offset.x();
            break;
        case Qt::AlignRight:
            newPosX = m_tableView->contentX()
                    - m_tableView->width()
                    + cellWidth
                    + offset.x();
            break;
        }

        m_tableView->setContentX(newPosX);
        m_tableView->forceLayout();
    }

    if (verticalAlignment) {
        qreal newPosY = 0;
        const qreal rowPosTop = int(cell.y() * (cellHeight + m_tableView->rowSpacing()));
        m_tableView->setContentY(0);
        m_tableView->forceLayout();
        m_tableView->setContentY(rowPosTop);
        m_tableView->forceLayout();

        switch (verticalAlignment) {
        case Qt::AlignTop:
            newPosY = m_tableView->contentY() + offset.y();
            break;
        case Qt::AlignVCenter:
            newPosY = m_tableView->contentY()
                    - m_tableView->height() / 2
                    + (cellHeight / 2)
                    + offset.y();
            break;
        case Qt::AlignBottom:
            newPosY = m_tableView->contentY()
                    - m_tableView->height()
                    + cellHeight
                    + offset.y();
            break;
        }

        m_tableView->setContentY(newPosY);
        m_tableView->forceLayout();
    }
#endif
}

QT_END_NAMESPACE