QwtSamplingThread Class Reference

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

#include <qwt_sampling_thread.h>

Inheritance diagram for QwtSamplingThread:

Classes
class	PrivateData

Public Slots
void	setInterval (double interval)
	Change the interval (in ms), when sample() is called.
void	stop ()
	Terminate the collecting thread.

Public Member Functions
double	interval () const
	Get the interval (in ms), between 2 calls of sample()
double	elapsed () const
	Get the time (in ms) since the thread was started.

Protected Member Functions
	QwtSamplingThread (QObject *parent=nullptr)
	Constructor.
virtual void	run () override
	Run the thread.
virtual void	sample (double elapsed)=0
	Collect a sample.

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

Constructor & Destructor Documentation

QwtSamplingThread()

QwtSamplingThread::QwtSamplingThread ( QObject *  parent = nullptr )

explicitprotected

Constructor.

Parameters

parent

Parent object

Destructor

Member Function Documentation

elapsed()

double QwtSamplingThread::elapsed

(

)

const

Get the time (in ms) since the thread was started.

Returns

Elapsed time in milliseconds

See also

QThread::start(), run()

interval()

double QwtSamplingThread::interval

(

)

const

Get the interval (in ms), between 2 calls of sample()

Returns

Interval in milliseconds

See also

setInterval()

run()

void QwtSamplingThread::run ( )

overrideprotectedvirtual

Run the thread.

Loop collecting samples started from QThread::start()

See also

stop()

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()

stop

void QwtSamplingThread::stop ( )

slot

Terminate the collecting thread.

See also

QThread::start(), run()

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The documentation for this class was generated from the following files:

• /home/runner/work/QWT/QWT/src/plot/qwt_sampling_thread.h
• /home/runner/work/QWT/QWT/src/plot/qwt_sampling_thread.cpp