Re: [matplotlib-devel] Enhancement to matplotlib's PyQt4 backend

[Dave P. <dpe...@en...>]

Darren Dale wrote:
> On Tue, Apr 28, 2009 at 12:19 PM, Pierre Raybaut <co...@py... 
> <mailto:co...@py...>> wrote:
>
>     2009/4/28 John Hunter <jd...@gm... <mailto:jd...@gm...>>:
>     >
>     >
>     > On Tue, Apr 28, 2009 at 8:18 AM, Pierre Raybaut
>     <co...@py... <mailto:co...@py...>>
>     > wrote:
>     >>
>     >> Hi all,
>     >>
>     >> I would like to contribute to matplotlib with this enhancement
>     for the
>     >> PyQt4 backend: the idea is to add a toolbar button to configure
>     figure
>     >> options (axes, curves, ...).
>     >>
>     >> It's based on a tiny module called formlayout to generate PyQt4
>     form
>     >> dialog automatically.
>     >>
>     >> Some screenshots:
>     >> http://code.google.com/p/formlayout/
>     >>
>     >> So, if you're interested (all the following is GPL2):
>     >>
>     >> *matplotlib patch*
>     >>
>     >> In FigureManagerQT.__init__, added:
>     >> self.canvas.axes = self.canvas.figure.add_subplot(111)
>     >>
>     >> In NavigationToolbar2QT._init_toolbar, added:
>     >> a = self.addAction(self._icon("customize.png"), 'Customize',
>     >> self.edit_parameters)
>     >> a.setToolTip('Edit curves line and axes parameters')
>     >>
>     >> Added the following method in NavigationToolbar2QT:
>     >> def edit_parameters(self):
>     >>    from figureoptions import figure_edit
>     >>    figure_edit(self.canvas, self)
>     >>
>     >> *additionnal modules and data*
>     >>
>     >> formlayout.py (http://code.google.com/p/formlayout/)
>     >> figureoptions.py (http://code.google.com/p/PyQtShell/)
>     >> customize.png (http://code.google.com/p/PyQtShell/)
>     >
>     > Hi Pierre -- this looks very nice (the last link is broken
>     though , I get a
>     > 404 error).  We would be happy to include this in matplotlib or as a
>
>     Here is the last link:
>     http://code.google.com/p/pyqtshell/
>
>     > toolkit.  To contribute it to to mpl,  the license needs to be
>     matplotlib
>     > compatible
>     >
>     (http://matplotlib.sourceforge.net/devel/coding_guide.html#licenses)
>     but we
>     > have more licensing flexibility in a toolkit, though we prefer
>     to keep
>     > everything BSD compatible where possible.   And of course you
>     would need to
>     > agree to maintain it :-) but I think many users would appreciate
>     a GUI plot
>     > configuration dialog.
>
>     I was not aware of this license restriction in matplotlib... I fully
>     understand the motivation, of course, but still: I wrote all this on
>     my free time which means no PyQt4 commercial license, so it can't be
>     anything but GPL. Sorry...
>
>
> I think you have overlooked a subtlety of PyQt4's license. The author 
> of PyQt4 wrote on the enthought-dev mailing list:
>
> "PyQt is GPL but has exceptions that allow it to be used with BSD code -
> hence it's Ok for TraitsBackendQt to be BSD.
>
> However, the exception imposes additional conditions which, to all intents
> and purposes, infects the code with the GPL. To be fair to people that
> should be made clear in any text.
>
> It's still a good idea for TraitsBackendQt to use a BSD license because it
> allows commercial (ie. non-GPL) users to use it without problems."
>
> Darren

I think it might be worth contacting the PyQt folks (Phil Thompson) 
about this.  I think there might be some differences here because Phil 
was the author of TraitsBackendQt and thus his efforts didn't quite fall 
under the "develop under a free license, your results needs to be GPL" 
clause Qt/PyQt have in their licensing.

-- Dave