Re: QT-based tools: Expressions of interest requested

[Matt Newville <newville@cars.uchicago.edu>]

Hi Emmanuel,

On Fri, Feb 24, 2012 at 11:37 AM, Emmanuel Mayssat <emayssat@gmail.com> wrote:
> pyQt widgets are traditionally written in C++ (native language of Qt) and
> wrapped for python using SIP.
> http://www.riverbankcomputing.com/software/sip/intro
>
> The best way to go about this Qt-epics is probably to
> 1/ pool all the C++ epics-aware widgets together
> 2/ develop SIP interface
>
> I don't know yet how the (excellent) pyepics package can play a role in this

For wx, we (Angus Gratton and I), subclassed many of the standard
wxPython classes to be associated with a PV.  For example,
PVStaticText is a wx.StaticText (~= Qt.QLabel) that has a PV
associated with it, including connection and monitor callbacks to
update the widget.   That is, when you create a PVStaticText, the
value displayed is always kept up-to-date, and connection state is
indicated by changing the background and foreground color.

I think that would be easy to do something similar with Qt (probably
easier than with wx)  and I think it could be done in python, without
C++.    That would make pyepics + python-Qt very easy to use.  I don't
know enough Qt  to do this on my own, but I'd be willing to help
someone interested in doing that. On the other hand, if there are
existing epics-aware subclasses of Qt widgets in C++, using something
like sip might be a good way to go.

Whether python has a place in a general purpose solution for a display
manager ala EDM/MEDM is different question.  It might be worth
considering, but a display manager is far outside my expertise.
Either way, as a current MEDM user, I'd very much be in favor of a
display manager based on Qt!

--Matt Newville