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

#include <qwt_sampling_thread.h>

Inheritance diagram for QwtSamplingThread:

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 () override

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

Definition at line 28 of file qwt_sampling_thread.h.

Constructor & Destructor Documentation

◆ ~QwtSamplingThread()

QwtSamplingThread::~QwtSamplingThread ( )

virtual

Destructor.

Definition at line 29 of file qwt_sampling_thread.cpp.

◆ QwtSamplingThread()

QwtSamplingThread::QwtSamplingThread ( QObject * parent = NULL )

explicitprotected

Constructor.

Definition at line 21 of file qwt_sampling_thread.cpp.

Member Function Documentation

◆ elapsed()

double QwtSamplingThread::elapsed ( ) const

Returns: Time (in ms) since the thread was started

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

Definition at line 62 of file qwt_sampling_thread.cpp.

◆ interval()

double QwtSamplingThread::interval ( ) const

Returns: Interval (in ms), between 2 calls of sample()

See also: setInterval()

Definition at line 53 of file qwt_sampling_thread.cpp.

◆ run()

void QwtSamplingThread::run ( )

overrideprotectedvirtual

Loop collecting samples started from QThread::start()

See also: stop()

Definition at line 83 of file qwt_sampling_thread.cpp.

◆ sample()

virtual void QwtSamplingThread::sample ( double elapsed )

protectedpure virtual

Collect a sample

Parameters

elapsed Time since the thread was started in seconds

Note: Due to a bug in previous version elapsed was passed as seconds instead of miliseconds. To avoid breaking existing code we stay with seconds for now.

◆ setInterval

void QwtSamplingThread::setInterval ( double msecs )

slot

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

Parameters

msecs Interval

See also: interval()

Definition at line 41 of file qwt_sampling_thread.cpp.

◆ stop

void QwtSamplingThread::stop ( )