void QwtPlotTextLabel::draw( QPainter *painter,
const QwtScaleMap &xMap, const QwtScaleMap &yMap,
const QRectF &canvasRect ) const
{
Q_UNUSED( xMap );
Q_UNUSED( yMap );
const int m = d_data->margin;
const QRectF adjustedRect = canvasRect.adjusted( m, m, -m, -m );
const bool doAlign = QwtPainter::roundingAlignment( painter );
if ( doAlign )
{
// when the paint device is aligning it is not one
// where scalability matters ( PDF, SVG ).
// As rendering a text label is an expensive operation
// we use a cache.
const QSize sz = d_data->text.textSize( painter->font() ).toSize();
if ( d_data->pixmap.isNull() || sz != d_data->pixmap.size() )
{
d_data->pixmap = QPixmap( sz );
d_data->pixmap.fill( Qt::transparent );
const QRect cacheRect( QPoint(), sz );
QPainter pmPainter( &d_data->pixmap );
d_data->text.draw( &pmPainter, cacheRect );
}
const QRect r = qwtItemRect( d_data->text.renderFlags(),
adjustedRect.toRect(), d_data->pixmap.size() );
painter->drawPixmap( r, d_data->pixmap );
}
else
{
d_data->text.draw( painter, adjustedRect );
}
}
/*!
\brief Align the text label
\param rect Canvas rectangle with margins subtracted
\param textSize Size required to draw the text
\return A rectangle aligned according the the alignment flags of
the text.
\sa setMargin(), QwtText::renderFlags(), QwtText::textSize()
*/
QRectF QwtPlotTextLabel::textRect(
const QRectF &rect, const QSizeF &textSize ) const
{
return qwtItemRect( d_data->text.renderFlags(), rect, textSize );
}
