QwtPlotItem bounding rect in widget coordinates

[StrikeByte]

Is there a way to get the bounding rect of a QwtPlotItem in widget coordinates?

The reason I'm asking is I want to create a generic way of selecting QwtPlotItems with the mouse (no matter what type they are)

[Uwe]

The bounding rectangle can be mapped to widget coordinates using: QwtPlot::canvasMap() and QwtScaleMap::transform().

Uwe

[StrikeByte]

Hello Uwe thanks for pointing me into the right direction

At the moment I'm still havinging some problems with the bounding rect of a VLine QwtPlotMarker it only returns a rect with a size of 1x1
I'm using qwt-6.1-multiaxes

This is the code I'm using to transform the bounding rect


QRectF boundingRect = QwtScaleMap::transform(m_plot->canvasMap((*it)->xAxis()),m_plot->canvasMap((*it)->yAxis()),(*it)->boundingRect());

[Uwe]

Basically this is a problem of the implementation of QwtPlotMarker::boundingRect(), that always returns the bounding rectangle of a point ( size is ( 0, 0 ), not ( 1, 1 ) ! ). The correct bounding rectangle for a VLine should be ( 0, -1 ), where the -1 indicates, that the autoscaler shouldn't take care of it vertically. You could fix this by overloading QwtPlotMarker::boundingRect().

Then your code has to check the horizontal and vertical intervals independently. Then in case of your VLine all clicks at a specific x coordinate do match regardless of the y coordinate.

Uwe