bool ValueTrackerAttributes::operator==( const ValueTrackerAttributes& r ) const
{
    return ( pen() == r.pen() &&
             areaBrush() == r.areaBrush() &&
             markerSize() == r.markerSize() &&
             isEnabled() == r.isEnabled() );
}
void paintElements( AbstractDiagram::Private *diagramPrivate, PaintContext* ctx,
                    const LabelPaintCache& lpc, const LineAttributesInfoList& lineList )
{
    AbstractDiagram* diagram = diagramPrivate->diagram;
    // paint all lines and their attributes
    const PainterSaver painterSaver( ctx->painter() );
    ctx->painter()->setRenderHint( QPainter::Antialiasing, diagram->antiAliasing() );

    QBrush curBrush;
    QPen curPen;
    QPolygonF points;
    KDAB_FOREACH ( const LineAttributesInfo& lineInfo, lineList ) {
        const QModelIndex& index = lineInfo.index;
        const ThreeDLineAttributes td = threeDLineAttributes( diagram, index );

        if ( td.isEnabled() ) {
            PaintingHelpers::paintThreeDLines( ctx, diagram, index, lineInfo.value,
                                               lineInfo.nextValue, td, &diagramPrivate->reverseMapper );
        } else {
            const QBrush brush( diagram->brush( index ) );
            const QPen pen( diagram->pen( index ) );

            // line goes from lineInfo.value to lineInfo.nextValue
            diagramPrivate->reverseMapper.addLine( lineInfo.index.row(), lineInfo.index.column(),
                                                   lineInfo.value, lineInfo.nextValue );

            if ( points.count() && points.last() == lineInfo.value && curBrush == brush && curPen == pen ) {
                // continue the current run of lines
            } else {
                // different painter settings or discontinuous line: start a new run of lines
                if ( points.count() ) {
                    PaintingHelpers::paintPolyline( ctx, curBrush, curPen, points );
                }
                curBrush = brush;
                curPen = pen;
                points.clear();
                points << lineInfo.value;
            }
            points << lineInfo.nextValue;
        }
    }
    if ( points.count() ) {
        // the last run of lines is yet to be painted - do it now
        PaintingHelpers::paintPolyline( ctx, curBrush, curPen, points );
    }

    KDAB_FOREACH ( const LineAttributesInfo& lineInfo, lineList ) {
        const ValueTrackerAttributes vt = valueTrackerAttributes( diagram, lineInfo.index );
        if ( vt.isEnabled() ) {
            PaintingHelpers::paintValueTracker( ctx, vt, lineInfo.nextValue );
        }
    }

    // paint all data value texts and the point markers
    diagramPrivate->paintDataValueTextsAndMarkers( ctx, lpc, true );
}
// this method is factored out from LineDiagram::paint, and contains
// the common parts of the method that  previously implemented all
// chart types in one
void LineDiagram::LineDiagramType::paintElements(
    PaintContext* ctx,
    DataValueTextInfoList& list,
    LineAttributesInfoList& lineList,
    LineAttributes::MissingValuesPolicy policy )
{
    Q_UNUSED( policy );
    // paint all lines and their attributes
    const PainterSaver painterSaver( ctx->painter() );
    if ( diagram()->antiAliasing() )
        ctx->painter()->setRenderHint ( QPainter::Antialiasing );
    LineAttributesInfoListIterator itline ( lineList );

    QBrush curBrush;
    QPen curPen;
    QPolygonF points;
    while ( itline.hasNext() ) {
        const LineAttributesInfo& lineInfo = itline.next();
        const QModelIndex& index = lineInfo.index;
        const ThreeDLineAttributes td = diagram()->threeDLineAttributes( index );
        const ValueTrackerAttributes vt = diagram()->valueTrackerAttributes( index );

        if( td.isEnabled() ){
            paintThreeDLines( ctx, index, lineInfo.value, lineInfo.nextValue, td.depth() );
        } else {
            const QBrush br( diagram()->brush( index ) );
            const QPen pn( diagram()->pen( index ) );
            if( points.count() && points.last() == lineInfo.value && curBrush == br && curPen == pn ) {
                // line goes from last value in points to lineInfo.nextValue
                reverseMapper().addLine( lineInfo.index.row(), lineInfo.index.column(), points.last(), lineInfo.nextValue );
                points << lineInfo.nextValue;
            } else {
                if( points.count() )
                    paintPolyline( ctx, curBrush, curPen, points );
                curBrush = br;
                curPen   = pn;
                points.clear();
                // line goes from lineInfo.value to lineInfo,nextValue
                reverseMapper().addLine( lineInfo.index.row(), lineInfo.index.column(), lineInfo.value, lineInfo.nextValue );
                points << lineInfo.value << lineInfo.nextValue;
            }
        }

        if( vt.isEnabled() )
            paintValueTracker( ctx, vt, lineInfo.value );
    }
    if( points.count() )
        paintPolyline( ctx, curBrush, curPen, points );
    // paint all data value texts and the point markers
    paintDataValueTextsAndMarkers( diagram(), ctx, list, true );
}