QwtPlotPicker Subclass Segfaults

[Uwe]

The stack indicates a crash starting with a QwtPlotZoomer - how the code you have shown related to this ?

Uwe

[npotts]

Hm.. That is a bit wierd. Ok, not sure why I missed that earlier. I removed all the zoomer code, it no longer sefgaults, but now there are NO markers. I am expecting a horizontal and vertical bars to follow the mouse around on the screen with some custom text. Again:


QwtPlotPicker .cpp and .h

class FreqdBmPicker : public QwtPlotPicker {
public:
	FreqdBmPicker( QWidget *canvas );
	FreqdBmPicker(int xAxis, int yAxis, RubberBand rubberBand, DisplayMode trackerMode, QWidget* canvas);
	virtual QwtText trackerTextF( const QPointF & ) const;
};

class FreqdBmPicker : public QwtPlotPicker {
public:
	FreqdBmPicker( QWidget *canvas );
	FreqdBmPicker(int xAxis, int yAxis, RubberBand rubberBand, DisplayMode trackerMode, QWidget* canvas);
	virtual QwtText trackerTextF( const QPointF & ) const;
};

To copy to clipboard, switch view to plain text mode 

QwtText TimeScaleDraw::label(double v) const { //Convert Double date to a string
  return QwtText(QDateTime::fromMSecsSinceEpoch((qint64) (v*1000)).toString("yyyy-MM-dd\nHH:mm:ss.zzz"));
}
 
FreqdBmPicker::FreqdBmPicker(int x, int y, RubberBand rb, DisplayMode dm, QWidget* w): QwtPlotPicker(x, y, rb, dm, w) {
  setTrackerMode( dm );
  setRubberBand( rb );
  setStateMachine( new QwtPickerTrackerMachine() );
  setTrackerPen(QColor(Qt::cyan));
  setRubberBandPen(QColor(Qt::cyan));
  qDebug() << isEnabled();
  setEnabled(true);
}
FreqdBmPicker::FreqdBmPicker( QWidget *canvas ): QwtPlotPicker( canvas ) {
  setTrackerMode( QwtPicker::AlwaysOn );
  setRubberBand( QwtPlotPicker::CrossRubberBand );
  setStateMachine( new QwtPickerTrackerMachine() );
  setTrackerPen(QColor(Qt::cyan));
  setRubberBandPen(QColor(Qt::cyan));
  qDebug() << isEnabled();
  setEnabled(true);
}
QwtText FreqdBmPicker::trackerTextF( const QPointF &pos ) const {
  QString rtn;
  switch ( (int) std::log10(pos.x())) {
    case 9: rtn = QString("(%1GHz, %2dBm)").arg(pos.x()/1e9, 0, 'f', 2); break;
    case 8:
    case 7:
    case 6: rtn = QString("(%1MHz, %2dBm)").arg(pos.x()/1e6, 0, 'f', 2); break;
    case 5:
    case 4:
    case 3: rtn = QString("(%1kHz, %2dBm)").arg(pos.x()/1e3, 0, 'f', 2); break;
    case 2:
    case 1:
    case 0:
    default: rtn = QString("(%1Hz, %2dBm)").arg(pos.x(), 0, 'f', 2); break;
  }
  rtn = rtn.arg(pos.y(), 0, 'f', 1);
  return QwtText(rtn);
}

QwtText TimeScaleDraw::label(double v) const { //Convert Double date to a string
  return QwtText(QDateTime::fromMSecsSinceEpoch((qint64) (v*1000)).toString("yyyy-MM-dd\nHH:mm:ss.zzz"));
}

FreqdBmPicker::FreqdBmPicker(int x, int y, RubberBand rb, DisplayMode dm, QWidget* w): QwtPlotPicker(x, y, rb, dm, w) {
  setTrackerMode( dm );
  setRubberBand( rb );
  setStateMachine( new QwtPickerTrackerMachine() );
  setTrackerPen(QColor(Qt::cyan));
  setRubberBandPen(QColor(Qt::cyan));
  qDebug() << isEnabled();
  setEnabled(true);
}
FreqdBmPicker::FreqdBmPicker( QWidget *canvas ): QwtPlotPicker( canvas ) {
  setTrackerMode( QwtPicker::AlwaysOn );
  setRubberBand( QwtPlotPicker::CrossRubberBand );
  setStateMachine( new QwtPickerTrackerMachine() );
  setTrackerPen(QColor(Qt::cyan));
  setRubberBandPen(QColor(Qt::cyan));
  qDebug() << isEnabled();
  setEnabled(true);
}
QwtText FreqdBmPicker::trackerTextF( const QPointF &pos ) const {
  QString rtn;
  switch ( (int) std::log10(pos.x())) {
    case 9: rtn = QString("(%1GHz, %2dBm)").arg(pos.x()/1e9, 0, 'f', 2); break;
    case 8:
    case 7:
    case 6: rtn = QString("(%1MHz, %2dBm)").arg(pos.x()/1e6, 0, 'f', 2); break;
    case 5:
    case 4:
    case 3: rtn = QString("(%1kHz, %2dBm)").arg(pos.x()/1e3, 0, 'f', 2); break;
    case 2:
    case 1:
    case 0:
    default: rtn = QString("(%1Hz, %2dBm)").arg(pos.x(), 0, 'f', 2); break;
  }
  rtn = rtn.arg(pos.y(), 0, 'f', 1);
  return QwtText(rtn);
}

To copy to clipboard, switch view to plain text mode 

Initialization and calling code. loadSweep() is called multiple times over the lifetime of the application

SweepInspector::SweepInspector(QWidget *parent) : QWidget(parent), data(NULL), d_curve(NULL), picker(NULL) {
  setupUi(this);
  plot->setObjectName( "SweepData" );
  plot->setTitle( "RF Sweep" );
  plot->setAxisTitle( QwtPlot::xBottom, "Frequency");
  plot->setAxisTitle( QwtPlot::yLeft, QString( "Power Level (dBm)"));
  plot->setAutoReplot(true);
 
  plot->enableAxis(QwtPlot::xBottom, true);
  plot->enableAxis(QwtPlot::yLeft, true);
  plot->enableAxis(QwtPlot::xTop, false);
  plot->enableAxis(QwtPlot::yRight, false);
 
  canvas = new QwtPlotCanvas();
  canvas->setPalette( Qt::black );
  canvas->setBorderRadius(0);
  plot->setCanvas(canvas);
 
  //Allow zooming / panning
  // zoomer = new QwtPlotZoomer( canvas );
  // zoomer->setRubberBandPen( QColor( Qt::white ) );
  // zoomer->setTrackerPen( QColor( Qt::white ) );
  panner = new QwtPlotPanner( canvas );
  panner->setMouseButton( Qt::MidButton );
 
  picker = new FreqdBmPicker(QwtPlot::xBottom, QwtPlot::yLeft, QwtPlotPicker::CrossRubberBand, QwtPicker::AlwaysOn, canvas);
 
 
  //Setup grid
  grid = new QwtPlotGrid();
  grid->enableXMin( true );
  grid->enableYMin( true );
  QColor color(Qt::gray); color.setAlpha(128);
  grid->setMajorPen( color, 1, Qt::DotLine );
  grid->setMinorPen( color, 1, Qt::DotLine );
  grid->attach( plot );
 
  //format in kHz, MHz, GHz, not raw values
  plot->setAxisScaleDraw(QwtPlot::xBottom, new FreqScaleDraw);
 
  //connects
  connect(timeIndex, SIGNAL(valueChanged(int)), this, SLOT(loadSweep(int)));
  connect(timeIndex, SIGNAL(sliderMoved(int)), this, SLOT(sliderMoved(int)));
}
 
void SweepInspector::loadSweep(int index) {
  //load in new sweep values from data
  if (data == NULL) return;
 
  //remove old data and get new
  if (d_curve) d_curve->attach(NULL);
  plot->detachItems();
  fsweep sweep = data->getSweep(index);
 
  d_curve = new QwtPlotCurve( timestamp->text() ); //Qwt will delete() this when its done with it
  d_curve->setRenderHint( QwtPlotItem::RenderAntialiased );
  d_curve->setStyle( QwtPlotCurve::Lines );
  d_curve->setPen( QColor( Qt::yellow ), 2, Qt::SolidLine );
  d_curve->setSamples( sweep );
  d_curve->attach(plot);
 
  delete(picker);
  picker = new FreqdBmPicker(QwtPlot::xBottom, QwtPlot::yLeft, QwtPlotPicker::CrossRubberBand, QwtPicker::AlwaysOn, canvas);
  connect(picker, SIGNAL(selected(QPointF)), this, SLOT(moved(QPointF)));
 
  QwtInterval frange = data->limits(FREQ);
  plot->setAxisScale(QwtPlot::xBottom, frange.minValue(), frange.maxValue(), (frange.maxValue() - frange.minValue())/ 5.0);
  plot->setAxisScale(QwtPlot::yLeft, -135, 20, 10.0);
  plot->setTitle( QString("RF Sweep @ %1").arg(timestamp->text()) );
  //set maximum zoom out
  // zoomer->setZoomBase(QRectF(QPointF(frange.minValue(), 20), QPointF(frange.maxValue(), -135)));
  // zoomer->zoomBase();
  plot->replot();
  plot->repaint();
}

SweepInspector::SweepInspector(QWidget *parent) : QWidget(parent), data(NULL), d_curve(NULL), picker(NULL) {
  setupUi(this);
  plot->setObjectName( "SweepData" );
  plot->setTitle( "RF Sweep" );
  plot->setAxisTitle( QwtPlot::xBottom, "Frequency");
  plot->setAxisTitle( QwtPlot::yLeft, QString( "Power Level (dBm)"));
  plot->setAutoReplot(true);

  plot->enableAxis(QwtPlot::xBottom, true);
  plot->enableAxis(QwtPlot::yLeft, true);
  plot->enableAxis(QwtPlot::xTop, false);
  plot->enableAxis(QwtPlot::yRight, false);

  canvas = new QwtPlotCanvas();
  canvas->setPalette( Qt::black );
  canvas->setBorderRadius(0);
  plot->setCanvas(canvas);

  //Allow zooming / panning
  // zoomer = new QwtPlotZoomer( canvas );
  // zoomer->setRubberBandPen( QColor( Qt::white ) );
  // zoomer->setTrackerPen( QColor( Qt::white ) );
  panner = new QwtPlotPanner( canvas );
  panner->setMouseButton( Qt::MidButton );

  picker = new FreqdBmPicker(QwtPlot::xBottom, QwtPlot::yLeft, QwtPlotPicker::CrossRubberBand, QwtPicker::AlwaysOn, canvas);


  //Setup grid
  grid = new QwtPlotGrid();
  grid->enableXMin( true );
  grid->enableYMin( true );
  QColor color(Qt::gray); color.setAlpha(128);
  grid->setMajorPen( color, 1, Qt::DotLine );
  grid->setMinorPen( color, 1, Qt::DotLine );
  grid->attach( plot );

  //format in kHz, MHz, GHz, not raw values
  plot->setAxisScaleDraw(QwtPlot::xBottom, new FreqScaleDraw);

  //connects
  connect(timeIndex, SIGNAL(valueChanged(int)), this, SLOT(loadSweep(int)));
  connect(timeIndex, SIGNAL(sliderMoved(int)), this, SLOT(sliderMoved(int)));
}

void SweepInspector::loadSweep(int index) {
  //load in new sweep values from data
  if (data == NULL) return;

  //remove old data and get new
  if (d_curve) d_curve->attach(NULL);
  plot->detachItems();
  fsweep sweep = data->getSweep(index);

  d_curve = new QwtPlotCurve( timestamp->text() ); //Qwt will delete() this when its done with it
  d_curve->setRenderHint( QwtPlotItem::RenderAntialiased );
  d_curve->setStyle( QwtPlotCurve::Lines );
  d_curve->setPen( QColor( Qt::yellow ), 2, Qt::SolidLine );
  d_curve->setSamples( sweep );
  d_curve->attach(plot);

  delete(picker);
  picker = new FreqdBmPicker(QwtPlot::xBottom, QwtPlot::yLeft, QwtPlotPicker::CrossRubberBand, QwtPicker::AlwaysOn, canvas);
  connect(picker, SIGNAL(selected(QPointF)), this, SLOT(moved(QPointF)));

  QwtInterval frange = data->limits(FREQ);
  plot->setAxisScale(QwtPlot::xBottom, frange.minValue(), frange.maxValue(), (frange.maxValue() - frange.minValue())/ 5.0);
  plot->setAxisScale(QwtPlot::yLeft, -135, 20, 10.0);
  plot->setTitle( QString("RF Sweep @ %1").arg(timestamp->text()) );
  //set maximum zoom out
  // zoomer->setZoomBase(QRectF(QPointF(frange.minValue(), 20), QPointF(frange.maxValue(), -135)));
  // zoomer->zoomBase();
  plot->replot();
  plot->repaint();
}

To copy to clipboard, switch view to plain text mode 

[Uwe]

A lot of code, but what is your question ?

Uwe

[npotts]

Haha, trees from the Forrest....


Essentially, my QwtPlotPickers are not appearing on the plots, and the format functions are never called.