Updating QPlot's curve with Qthread

[Santosh Reddy]

I am not very sure of Qwt, but I thing I suspect is that, "graphs *hereitis" is the QThread's constructor parameter which is stored in "yeah" member variable, an then it is used later in the context of the QThread.

Now internally yeah->updateCurve(..) might be emitting some signals which need to propagated to the GUI thread, only then the graph will be updated. You may not be able to make signals work until the "graphs" object (yeah) is created in the context of the working Thread, or at least the working thread has the ownership.

[jendral_hxr]

Ah, yep. So I need to make SIGNAL which triggers certain GUI-related (widget) SLOT?
And I am sorry, the variable names should have been clearer

[Santosh Reddy]

I mean who is owner of the graph, QwtPlot and QwtPlotCurve class objects?

[jendral_hxr]

The 'owner' the QwtPlot, QwtPlotCurve is a class I made myself.

After reading queuedcustomtype example, it's clear to me: I need to make a SIGNAL in a thread to pass some value to a SLOT of widget which has that 'updating' thread So every self-updating widget has to have its own thread within?

Thanks, Santosh Reddy

ummh, it's just embarrassing that the title is QPlot instead of QwtPlot, duh!

[Uwe]

For any type of "realtime" plot I strongly recommend to decouple the refresh rate of your plot widget from the sample rate.

Use a QTimer, that periodically checks if new samples have been collected and calls replot then.

Uwe