QT GUI blocks do not replicate all functionality of WX blocks

[dkozel]

This issue tracks the features missing in the QT blocks compared to WX.

Missing Features

• XY plotting
• Stripchart time sink
• Histogram chart
• Variable Persistance in the time sink (Bring Persistence to QTGUI Time Sink to Enable "Eye Diagrams" #1631)

[marcusmueller]

This would by the way make great GSoC features :) can you check whether this might be an amendment to an existing GSoC idea or a new one? Note that listing it as GSoC idea wouldn't mean we discourage non-GSoC contributions!

[dcajacob]

Might want to pull in my latest issue since this seems to be a good umbrella for it: #1631

[dkozel]

Also relevant, putting time and effort into Qwt based blocks isn't very useful if we'll be moving to the pyqtgraph library.
#1634

[noc0lour]

The problem is PyQwt, Qwt is not affected, If someone dares to rewrite examples and apps in C++ Qwt is on the table.

[marcusmueller]

@noc0lour I remember "back in my days", that QWT was a dependency nightmare, has that gotten better? I'm afraid of QWT5/6 on QT4/5 fun all the way to 3.9.

[noc0lour]

Dependency graph doesn't look too bad?

 * dependency graph for x11-libs/qwt-6.1.3-r1
 `--  x11-libs/qwt-6.1.3-r1  amd64 
   `--  virtual/opengl-7.0-r1  (virtual/opengl) amd64 
   `--  dev-qt/qtcore-4.8.7-r4  (dev-qt/qtcore) amd64 
   `--  dev-qt/qtgui-4.8.7  (dev-qt/qtgui) amd64 
   `--  dev-qt/designer-4.8.7  (dev-qt/designer) amd64 
   `--  dev-qt/qtopengl-4.8.7  (dev-qt/qtopengl) amd64 
   `--  dev-qt/qtsvg-4.8.7  (dev-qt/qtsvg) amd64 
   `--  dev-qt/qtconcurrent-5.9.4  (dev-qt/qtconcurrent) ~amd64 
   `--  dev-qt/qtcore-5.9.4-r2  (dev-qt/qtcore) ~amd64 
   `--  dev-qt/qtgui-5.9.4-r3  (dev-qt/qtgui) ~amd64 
   `--  dev-qt/qtprintsupport-5.9.4  (dev-qt/qtprintsupport) ~amd64 
   `--  dev-qt/qtwidgets-5.9.4-r1  (dev-qt/qtwidgets) ~amd64 
   `--  dev-qt/designer-5.9.4  (dev-qt/designer) ~amd64 
   `--  dev-qt/qtopengl-5.9.4  (dev-qt/qtopengl) ~amd64 
   `--  dev-qt/qtsvg-5.9.4-r1  (dev-qt/qtsvg) ~amd64 

Depends of course if qt4/qt5 support is enabled, and there are some other options which most distributions have enabled probably.

[marcusmueller]

I'd agree, that looks fine enough.

[jdemel]

Is XY plotting really missing from Qt GUI? This is essentially a constellation plot.
As a quick test, I put together a small flowgraph for Oscillofun. It consists of a 2-channel wav source, connected to a 2-c audio sink. The plotting is either done with WX Gui Scope Sink in XY mode, or with an additional float to complex block and a Qt Constellation Sink.
It does not look as amazing as in the linked video, but it works. Altough, this would be a great addition if it could look as amazing as in the video. This might draw interest to GR.