Using theme with QTGUI qss files makes transition lines between points on QT GUI Constellation Sink

The new GRC theme system using qss files looks pretty neat and seems
user configurable. Thanks.

To use this, with my build-gnuradio installed setup, I had to create a
file under my home user folder at /home/me/.gnuradio/config.conf and I
to add the following to that file.

qss = /usr/local/share/gnuradio/themes/alt.qss

To go back to the normal theme I just commented out that line, like

#qss = /usr/local/share/gnuradio/themes/alt.qss

All this works just fine.


I did run into one issue using this with a QT GUI Constellation Sink.

The constellation points have the lines turned on running between them
so they look like a transition diagram instead of what I think of as a
constellation diagram).

So before I asked for help here I thought I’d have some fun with it and
tried some stuff on my own.

I tried adding the following to the alt.qss file in my
/usr/local/share/gnuradio/themes folder (had to change file permissions
the qss files to do this with my editor - but I am guessing the
change is not an issue).

ConstellationDisplayPlot {
qproperty-line_style1: None;
qproperty-line_style2: None;
qproperty-line_style3: None;

I put this between the VectorDIsplayPlot entries and the QwtPlotCanvas
I also tried replacing the similar lines in DisplayPlot with the
for “None” I show above.

None of that changed the constellation to remove the lines between

To make sure I was having ‘some’ effect, I tried making the background
the whole plot an ugly green color (changing the top QWidget
background-color) and that worked, so I am at least affecting something
with that file if I had the syntax and context correct.

I did the requesite Google search on “QtCore.Qt.DashLine” to see if
was a syntax aside from “None” that would be correct, but while I could
find syntax for several other line choices I did not a find syntax for a
choice for no line. So it is possible the issue is deeper than just a
configuration line.


Any idea how to make the QT constellation plots not have the transition
lines between points when using one of the qss sheets?


  • John

Try removing these lines from the DisplayPlot {} section:

qproperty-line_style1: SolidLine;
qproperty-line_style2: DashLine;
qproperty-line_style3: DotLine;

Since the lines are also in Frequency plot and Vector plot sections,
that change should not affect them.
It might mess up a Time plot, but then you can just add those lines to
that section to fix it.

— Seth