Qwt User's Guide  6.0.2
Public Slots | Public Member Functions | Protected Member Functions
QwtSamplingThread Class Reference

#include <qwt_sampling_thread.h>

List of all members.

Public Slots

void setInterval (double interval)
void stop ()

Public Member Functions

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

Protected Member Functions

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

Detailed Description

A thread collecting samples at regular intervals.

Contiounous 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 perodically 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 ( )
protectedvirtual

Loop collecting samples started from QThread::start()

See also:
stop()
virtual void QwtSamplingThread::sample ( double  elapsed)
protectedpure virtual

Collect a sample

Parameters:
elapsedTime since the thread was started in miliseconds
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()