Qwt User's Guide
QwtSamplingThread Class Reference

A thread collecting samples at regular intervals. More...

#include <qwt_sampling_thread.h>

Public Slots

void setInterval (double interval)
void stop ()

Public Member Functions

virtual ~QwtSamplingThread ()
 Destructor.
double interval () const
double elapsed () const

Protected Member Functions

 QwtSamplingThread (QObject *parent=NULL)
 Constructor.
virtual void run ()
virtual void sample (double elapsed)=0

Detailed Description

A thread collecting samples at regular intervals.

Continuous signals are converted into a discrete signal by collecting samples at regular intervals. A discrete signal can be displayed by a QwtPlotSeriesItem on a QwtPlot widget.

QwtSamplingThread starts a thread calling periodically sample(), to collect and store ( or emit ) a single sample.

See also:
QwtPlotCurve, QwtPlotSeriesItem

Member Function Documentation

double QwtSamplingThread::elapsed ( ) const
Returns:
Time (in ms) since the thread was started
See also:
QThread::start(), run()
double QwtSamplingThread::interval ( ) const
Returns:
Interval (in ms), between 2 calls of sample()
See also:
setInterval()
void QwtSamplingThread::run ( ) [protected, virtual]

Loop collecting samples started from QThread::start()

See also:
stop()
virtual void QwtSamplingThread::sample ( double  elapsed) [protected, pure virtual]

Collect a sample

Parameters:
elapsedTime since the thread was started in milliseconds
void QwtSamplingThread::setInterval ( double  interval) [slot]

Change the interval (in ms), when sample() is called. The default interval is 1000.0 ( = 1s )

Parameters:
intervalInterval
See also:
interval()
void QwtSamplingThread::stop ( ) [slot]

Terminate the collecting thread

See also:
QThread::start(), run()

List of all members.

 All Classes Functions Variables Typedefs Enumerations Enumerator