QwtPlotMarker On the Center of the Plot

[Uwe]

Something like this:

class TextItem: public QwtPlotItem
{
public:
    void setText( const QString &text )
    {
        m_text = text;
    }
 
    virtual void draw( QPainter *painter,
        const QwtScaleMap &, const QwtScaleMap &,
        const QRectF &canvasRect ) const
    {
        painter->drawText( canvasRect, Qt::AlignCenter, m_text );
    }
 
private:
    QString m_text;
};

class TextItem: public QwtPlotItem
{
public:
    void setText( const QString &text )
    {
        m_text = text;
    }

    virtual void draw( QPainter *painter,
        const QwtScaleMap &, const QwtScaleMap &,
        const QRectF &canvasRect ) const
    {
        painter->drawText( canvasRect, Qt::AlignCenter, m_text );
    }

private:
    QString m_text;
};

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Attach this item to your plot like a curve and the draw method will be part of the plot image composition.

Uwe