tooltip labelAlignment

[Surfman19]

Hi,

i use a QwtPlotMarker to visualize the data value of a qwtplotcurve. when i move the mouse over the datapoint the value will be visualized in the QwtPlotMarker.

When i move the mouse into the corners the QwtPlotMarker gets displayed out of widget view:
http://s13.postimg.org/bq6vsrd9j/IMG_6968.jpg

how can i implement some sort of auto setLabelAlignment?

Thanks,
Surf

[Uwe]

Why using a marker, when implementing a tooltip ?
Instead you could use QToolTip itself - or maybe easier a customized QwtPlotPicker with a trackerText method, that returns the value of a datapoint or QString::null else.

Uwe

[Surfman19]

i mean QwtPlotMarker. the label for QwtPlotMarker should re-adjust automatically in case if i move the mouse over a datapointer beeing at the outer corner...
do you know what i try to achieve?

here is the snipped i have at the moment:

std::shared_ptr<QwtPlot> plot;
std::shared_ptr<QwtPlotCurve> curve1;
std::shared_ptr<QwtPlotCurve> curve2;
std::shared_ptr<QwtPlotMarker> marker;	
std::shared_ptr<QwtPlotShapeItem> plotItem;
 
///////////////////
 
bool MainWindow::eventFilter(QObject *obj, QEvent *event) 
{
	if (event->type() == QEvent::MouseMove)
	{
		QMouseEvent *m = static_cast<QMouseEvent*>(event);
 
		QwtPlotItemList curves = plot.get()->itemList(QwtPlotItem::Rtti_PlotCurve);
		if (curves.size() == 0) {
			return false;
		}
 
		double dist1 = 1e99;
		double dist2 = 1e99;
 
		int point_index1 = static_cast<QwtPlotCurve*>(curves[0])->closestPoint(QPoint(m->x(), m->y()), &dist1);
		int point_index2 = static_cast<QwtPlotCurve*>(curves[1])->closestPoint(QPoint(m->x(), m->y()), &dist2);
 
		if (point_index1 != -1 && point_index2 != -1) {
			QPointF p;
 
			if (dist1 < dist2) { 
				p = static_cast<QwtPlotCurve*>(curves[0])->sample(point_index1);
			}
			else {
				p = static_cast<QwtPlotCurve*>(curves[1])->sample(point_index2);
			}
 
			//marker->setSpacing(10);
			marker->setLineStyle(QwtPlotMarker::Cross);
			marker->setLinePen(QPen(Qt::black, 2, Qt::DotLine));
			marker->setLabel("t: " + QString::number(p.x()) + ", Volts: " + QString::number(p.y()));
			marker->setLabelAlignment(Qt::AlignRight | Qt::AlignTop); // | Qt::AlignCenter);
			//marker->setLabelAlignment(Qt::AlignCenter | Qt::AlignCenter);
			marker->setXValue(p.x());
			marker->setYValue(p.y());
		}
		marker->attach(plot.get());
		plot->replot();
	}
 
	return false;
}

std::shared_ptr<QwtPlot> plot;
std::shared_ptr<QwtPlotCurve> curve1;
std::shared_ptr<QwtPlotCurve> curve2;
std::shared_ptr<QwtPlotMarker> marker;	
std::shared_ptr<QwtPlotShapeItem> plotItem;

///////////////////

bool MainWindow::eventFilter(QObject *obj, QEvent *event) 
{
	if (event->type() == QEvent::MouseMove)
	{
		QMouseEvent *m = static_cast<QMouseEvent*>(event);

		QwtPlotItemList curves = plot.get()->itemList(QwtPlotItem::Rtti_PlotCurve);
		if (curves.size() == 0) {
			return false;
		}

		double dist1 = 1e99;
		double dist2 = 1e99;

		int point_index1 = static_cast<QwtPlotCurve*>(curves[0])->closestPoint(QPoint(m->x(), m->y()), &dist1);
		int point_index2 = static_cast<QwtPlotCurve*>(curves[1])->closestPoint(QPoint(m->x(), m->y()), &dist2);

		if (point_index1 != -1 && point_index2 != -1) {
			QPointF p;
			
			if (dist1 < dist2) { 
				p = static_cast<QwtPlotCurve*>(curves[0])->sample(point_index1);
			}
			else {
				p = static_cast<QwtPlotCurve*>(curves[1])->sample(point_index2);
			}

			//marker->setSpacing(10);
			marker->setLineStyle(QwtPlotMarker::Cross);
			marker->setLinePen(QPen(Qt::black, 2, Qt::DotLine));
			marker->setLabel("t: " + QString::number(p.x()) + ", Volts: " + QString::number(p.y()));
			marker->setLabelAlignment(Qt::AlignRight | Qt::AlignTop); // | Qt::AlignCenter);
			//marker->setLabelAlignment(Qt::AlignCenter | Qt::AlignCenter);
			marker->setXValue(p.x());
			marker->setYValue(p.y());
		}
		marker->attach(plot.get());
		plot->replot();
	}

	return false;
}

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[Uwe]

i mean QwtPlotMarker. the label for QwtPlotMarker should re-adjust automatically in case if i move the mouse over a datapointer beeing at the outer corner...
do you know what i try to achieve?

Guess yes, you want to use QwtPlotPicker - even if not knowing it yet :-/

Uwe

[Surfman19]

why cant i use QwtPlotMarker?

do you have a small QwtPlotPicker example? and how do you auto - align the label to avoid the issue i have?

how can you set the label of the QwtPlotPicker, i look for somth like: void setTrackerText(const QString &str);
the label should be e.g.: "Amplitude: 1.0, Sample: 10" ... the closest distance to a point of those 2 curves, as in my sample before.

i see QwtPlotPicker has a move member function: void QwtPlotPicker::move(const QPoint &pos)

... how do you know the distance to transform? this will depend on the size of the label, basically the number of characters...

[Uwe]

Have a look at the curvetracker example - not exactly your use case, but you should get the idea.

Uwe