Re: [Discuss-gnuradio] qt_gui_time

[Marcus D. Leech]

On 03/10/2019 06:26 PM, Marcus Müller wrote:
> Hi Wayne, Hi Joe,
>
> you're right – we've been urging people to switch away from WX since at
> least 2014, and now we're finally removing it; with a bit of a heavy
> heart, to be honest: Without feature equality, removing an alternative
> feels bad, but we simply couldn't maintain the WX code anymore, and had
> to find the resources to maintain QT stuff first.
> So, no, we don't have that specific visualization in Qt, sorry. Joe,
> this means we've long stopped supporting your widget – it works on most
> machines, on others it doesn't, and we can't really help you in the
> latter case.
>
> Now, would one get started with developing a strip chart for Qt? Either
> one cheats a bit and just implements something that hands n_points
> sized chunks of data to the Qt GUI time sink, which always are
> basically the last chunk, with old samples "shifted out" and new
> samples "shifted in", or one would actually go and do a deep C++/Qt
> dive and write a proper stripchart widget.
>
> Best regards,
> Marcus
I use the Qt Vector sink for strip-charts.

All the strip-chartiness is handled in helper code, and the Vector just 
shows vectors at strip-chartly low rates.

My spectro_radiometer app does this.

Basically, feed a Qt Vector sink from an vector-add-const block which is 
being feed a stream of zeros.  On a regular basis, via the magic
  of function probes, update the "constant" that is added.  That vector 
constant is the strip-chart contents.  The Vector sink doesn't even
  know that it's acting as a stripchart function.  Easy-peasy, and 
nothing special required in Qt land other than what's already there.

I implemented the strip-chart functionality in the Wx widgets all those 
years ago.  It was a bit of a hack then, and I'm kinda happy to see
  the Wx widgets going away.  They had portability issues, and often 
also had horrendous performance issues.


> On Sun, 2019-03-10 at 16:12 -0600, Joe Martin wrote:
> > Hi Wayne,
> >
> > I am using the strip-chart option of the WX GUI Scope Sink block in
> > GRC to perform drift scans in my radio astronomy project.  Works like
> > a champ!
> >
> > Select “Stripchart” in the Trigger option.
> >
> > Regards,
> >
> > Joe
> >
> > > On Mar 10, 2019, at 3:24 PM, Wayne Hilliard <address@hidden>
> > > wrote:
> > >
> > > Hello,
> > > Question. Has there been any movement on adding a strip chart
> > > option to this gui?
> > >
> > > I know WX_gui usage is discouraged and i have a radio astronomy app
> > > I've been working on that uses QT_Gui.
> > >
> > > I've looked around some on github and don't have a clue on where I
> > > would start to try something on my own.
> > >
> > > Any help would be appreciated .
> > > Thanks in advance!!
> > >
> > > Wayne Hilliard
> > > _______________________________________________
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