#91 increase test coverage for PointBrowser

nansat/pointbrowser.py

@@ -19,9 +19,9 @@
 import numpy as np
 
 try:
-    if 'DISPLAY' not in os.environ:
-        import matplotlib; matplotlib.use('Agg')
     import matplotlib
+    if 'DISPLAY' not in os.environ:
+        matplotlib.use('Agg')
     import matplotlib.pyplot as plt
 except ImportError:
     MATPLOTLIB_IS_INSTALLED = False
@@ -63,11 +63,11 @@ class PointBrowser():
     lines = None
     coordinates = None
 
-    def __init__(self, data, fmt='x-k', **kwargs):
+    def __init__(self, data, fmt='x-k', force_interactive=True, **kwargs):
         """Open figure with imshow and colorbar"""
         if not MATPLOTLIB_IS_INSTALLED:
             raise ImportError(' Matplotlib is not installed ')
-        if not matplotlib.is_interactive():
+        if force_interactive and not matplotlib.is_interactive():
             raise SystemError('''
         Python is started with -pylab option, transect will not work.
         Please restart python without -pylab.''')

nansat/tests/test_pointbrowser.py

@@ -16,29 +16,22 @@
 from nansat.pointbrowser import PointBrowser
 
 try:
-    if 'DISPLAY' not in os.environ:
-        import matplotlib; matplotlib.use('Agg')
     import matplotlib
+    if 'DISPLAY' not in os.environ:
+        matplotlib.use('Agg')
     import matplotlib.pyplot as plt
-    plt.switch_backend('qt5agg')
 except ImportError:
     MATPLOTLIB_IS_INSTALLED = False
 else:
     MATPLOTLIB_IS_INSTALLED = True
 
 
 class PointBrowserTest(unittest.TestCase):
-    @unittest.skipUnless(MATPLOTLIB_IS_INSTALLED and 'DISPLAY' in os.environ, 'Matplotlib is required')
-    def setUp(self):
-        plt.switch_backend('qt5agg')
-        plt.ion()
-        data = np.ndarray(shape=(4, 4), dtype=float, order='F')
-        self.point = PointBrowser(data)
-
     def test_onclick(self):
+        point_browser = PointBrowser(np.zeros((4, 4)), force_interactive=False)
         event = Event(xdata=0, ydata=0, key=None)
-        self.point.onclick(event)
-        t = self.point._convert_coordinates()[0]
+        point_browser.onclick(event)
+        t = point_browser._convert_coordinates()[0]
         self.assertIsInstance(t, np.ndarray)
         xPoints = t[0]
         self.assertIsInstance(xPoints, np.ndarray)
@@ -48,20 +41,26 @@ def test_onclick(self):
         self.assertEqual(yPoints[0], event.ydata, "y coordinates is set wrong")
 
     def test_onclick_multilines(self):
+        point_browser = PointBrowser(np.zeros((4, 4)), force_interactive=False)
         events = []
         events.append(Event(xdata=0, ydata=0, key=None))
         events.append(Event(xdata=1, ydata=0, key=None))
         events.append(Event(xdata=2, ydata=2, key='AnyKeyButZorAltZ'))
         events.append(Event(xdata=2, ydata=3, key=None))
         for event in events:
-            self.point.onclick(event)
-        points = self.point._convert_coordinates()
+            point_browser.onclick(event)
+        points = point_browser._convert_coordinates()
         self.assertEqual(len(points), 2, 'There should be two transects')
         self.assertTrue(np.alltrue(points[0] == np.array([[0, 1], [0, 0]])),
                         't1 is not correct')
         self.assertTrue(np.alltrue(points[1] == np.array([[2, 2], [2, 3]])),
                         't2 is not correct')
 
+    @unittest.skipIf('DISPLAY' in os.environ, 'Non-interactive mode is required')
+    def test_fail_non_interactive(self):
+        with self.assertRaises(SystemError):
+            point_browser = PointBrowser(np.zeros((4, 4)))
+
 class Event:
     def __init__(self, **kwds):
         self.__dict__.update(kwds)