From 255ac689992fff672c9adbd0777135c4c0add1d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Johannes=20Sch=C3=B6nberger?= <jschoenberger@demuc.de>
Date: Wed, 29 May 2013 20:17:17 +0200
Subject: [PATCH] Avoid import of matplotlib QT lib if QT is not installed

---
 skimage/viewer/utils/core.py | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/skimage/viewer/utils/core.py b/skimage/viewer/utils/core.py
index 0dcd4176..0b97d8c3 100644
--- a/skimage/viewer/utils/core.py
+++ b/skimage/viewer/utils/core.py
@@ -2,13 +2,18 @@ import warnings
 
 import numpy as np
 
+from ..qt import qt_api
+
 try:
     import matplotlib as mpl
     from matplotlib.figure import Figure
     from matplotlib import _pylab_helpers
     from matplotlib.colors import LinearSegmentedColormap
-    from matplotlib.backends.backend_qt4 import FigureManagerQT
-    from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg
+    if qt_api is None:
+        raise ImportError
+    else:
+        from matplotlib.backends.backend_qt4 import FigureManagerQT
+        from matplotlib.backends.backend_qt4agg import FigureCanvasQTAgg
 except ImportError:
     FigureCanvasQTAgg = object  # hack to prevent nosetest and autodoc errors
     LinearSegmentedColormap = object