Date-time axis

[Cat]

I inherit class from QwtScaleDraw to show date-time axis:

class TimeScaleDraw: public QwtScaleDraw {
public:
 
TimeScaleDraw(const QDateTime &base) : baseDateTime(base)
 
  {
  setLabelRotation(0);
  setLabelAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  setSpacing(20);
  }
  virtual QwtText label(double v) const
  {
  QDateTime dateTime;
  dateTime = dateTime.fromTime_t(v);
  return dateTime.toString("yyyy.MM.dd\nhh:mm:ss");
  }
 private:
QDateTime baseDateTime;
  };

class TimeScaleDraw: public QwtScaleDraw {
public:

TimeScaleDraw(const QDateTime &base) : baseDateTime(base)

  {
  setLabelRotation(0);
  setLabelAlignment(Qt::AlignHCenter | Qt::AlignVCenter);
  setSpacing(20);
  }
  virtual QwtText label(double v) const
  {
  QDateTime dateTime;
  dateTime = dateTime.fromTime_t(v);
  return dateTime.toString("yyyy.MM.dd\nhh:mm:ss");
  }
 private:
QDateTime baseDateTime;
  };

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In main file I use it as:

funPlot->setAxisScaleDraw(QwtPlot::xBottom, new TimeScaleDraw(QDateTime::currentDateTime()));

funPlot->setAxisScaleDraw(QwtPlot::xBottom, new TimeScaleDraw(QDateTime::currentDateTime()));

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I want to see the current date-time by default when I run the app. Is it possible? Now it displays as 1970.01.00 00:00:00 with an appropriate scale.

[Uwe]

Now it displays as 1970.01.00 00:00:00 with an appropriate scale.

Yes this is the null date ( 0 ms from Epoch ). I recommend to use the QwtDate classes - see http://qwt.sourceforge.net/class_qwt_date.html#details.

Uwe