reimplement drawTracker issue in my picker class derived from QwtPlotPicker

[josentop]

Hi,
I use QwtPlotPicker to track user's moving by Left/Right key in plot. I subclass QwtPlotPicker and reimplement trackerRect and drawTracker method to show one vertical dotline in plot, I got it but the vertical dotline is very short and not my expected. please see follow code and result. I need the vertical dotline to be as from bottom to top, anyone can give some suggestions? thanks.

QRect CsmPicker::trackerRect(const QFont &) const
{
	QPoint p = trackerPosition();
	const QwtPlot *pickerPlot = plot();
	const QwtScaleDiv *scaleDiv = pickerPlot->axisScaleDiv(QwtPlot::yLeft);
	int min = scaleDiv->lowerBound();
	int max = scaleDiv->upperBound();
 
	QRect rect(0, min, 100, (max-min));
	rect.moveTo(p.x(), min);
 
	return rect;
}
 
void CsmPicker::drawTracker(QPainter *painter) const
{
	QPoint p = trackerPosition();
	const QwtPlot *pickerPlot = plot();
	const QwtScaleDiv *scaleDiv = pickerPlot->axisScaleDiv(QwtPlot::yLeft);
	int min = scaleDiv->lowerBound() + 5;
	int max = scaleDiv->upperBound() - 5;
 
	QPen pen(QColor(180, 180, 180));
	pen.setStyle(Qt::DotLine);
	painter->setPen(pen);
 
	QFont font = painter->font();
	painter->setClipRect(trackerRect(font));
	painter->drawLine(p.x(), min, p.x(), max);
 
	painter->drawText(p.x(), p.y(), "Test");
	if (p.x() < 0) p.setX(0);
	emit mouseMoving(p);
}

QRect CsmPicker::trackerRect(const QFont &) const
{
	QPoint p = trackerPosition();
	const QwtPlot *pickerPlot = plot();
	const QwtScaleDiv *scaleDiv = pickerPlot->axisScaleDiv(QwtPlot::yLeft);
	int min = scaleDiv->lowerBound();
	int max = scaleDiv->upperBound();

	QRect rect(0, min, 100, (max-min));
	rect.moveTo(p.x(), min);

	return rect;
}

void CsmPicker::drawTracker(QPainter *painter) const
{
	QPoint p = trackerPosition();
	const QwtPlot *pickerPlot = plot();
	const QwtScaleDiv *scaleDiv = pickerPlot->axisScaleDiv(QwtPlot::yLeft);
	int min = scaleDiv->lowerBound() + 5;
	int max = scaleDiv->upperBound() - 5;

	QPen pen(QColor(180, 180, 180));
	pen.setStyle(Qt::DotLine);
	painter->setPen(pen);

	QFont font = painter->font();
	painter->setClipRect(trackerRect(font));
	painter->drawLine(p.x(), min, p.x(), max);

	painter->drawText(p.x(), p.y(), "Test");
	if (p.x() < 0) p.setX(0);
	emit mouseMoving(p);
}

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Test.png

[Uwe]

What about using QwtPicker::VLineRubberBand ?

Uwe

[josentop]

thanks for your reply. rubberBand only for stateMachine points selection mode, but in my case, it is mouse tracking mode.

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Added after 31 minutes:

It is fixed using QwtPicker::VLineRubberBand and set QwtPickerMachine to QwtPickerTrackerMachine. thanks.