[matplotlib-devel] Patch for Qt4 backend for IPython GUI

[Brian G. <ell...@gm...>]

Hi,

We are in the process of getting our new Qt IPython GUI working with
matplotlib.  One problem we have found is that the matplotlib qt4
backend always creates a QApplication.  This is problematic in
situations where another part of an application has already created a
QApplication.  The fix is to have matplotlib first see if a
QApplication already exists and then use that one.  The attached patch
implements this fix.  If needed, Fernando can help test this, but I
think the change is minor enough that it should be good to go.

Cheers,

Brian