Method render

3rdparty/qwt/src/qwt_plot_renderer.cpp:482–664

! Paint the contents of a QwtPlot instance into a given rectangle. \param plot Plot to be rendered \param painter Painter \param plotRect Bounding rectangle \sa renderDocument(), renderTo(), QwtPainter::setRoundingAlignment() */

   \sa renderDocument(), renderTo(), QwtPainter::setRoundingAlignment()
 */
void QwtPlotRenderer::render( QwtPlot* plot,
    QPainter* painter, const QRectF& plotRect ) const
{
    if ( painter == 0 || !painter->isActive() ||
        !plotRect.isValid() || plot->size().isNull() )
    {
        return;
    }

    if ( !( m_data->discardFlags & DiscardBackground ) )
        QwtPainter::drawBackgound( painter, plotRect, plot );

    /*
       The layout engine uses the same methods as they are used
       by the Qt layout system. Therefore we need to calculate the
       layout in screen coordinates and paint with a scaled painter.
     */
    QTransform transform;
    transform.scale(
        double( painter->device()->logicalDpiX() ) / plot->logicalDpiX(),
        double( painter->device()->logicalDpiY() ) / plot->logicalDpiY() );

    QRectF layoutRect = transform.inverted().mapRect( plotRect );

    if ( !( m_data->discardFlags & DiscardBackground ) )
    {
        // subtract the contents margins

        const QMargins m = plot->contentsMargins();
        layoutRect.adjust( m.left(), m.top(), -m.right(), -m.bottom() );
    }

    QwtPlotLayout* layout = plot->plotLayout();

    int baseLineDists[QwtAxis::AxisPositions];
    int canvasMargins[QwtAxis::AxisPositions];

    for ( int axisPos = 0; axisPos < QwtAxis::AxisPositions; axisPos++ )
    {
        canvasMargins[axisPos] = layout->canvasMargin( axisPos );

        if ( m_data->layoutFlags & FrameWithScales )
        {
            const QwtAxisId axisId( axisPos );

            QwtScaleWidget* scaleWidget = plot->axisWidget( axisId );
            if ( scaleWidget )
            {
                baseLineDists[axisPos] = scaleWidget->margin();
                scaleWidget->setMargin( 0 );
            }

            if ( !plot->isAxisVisible( axisId ) )
            {
                // When we have a scale the frame is painted on
                // the position of the backbone - otherwise we
                // need to introduce a margin around the canvas