Fix error when canceling import (#107)

* Fix  error when canceling import

* Add tests

* Fix flake8

Author: BasVolkers

march_rqt_gait_generator/src/march_rqt_gait_generator/gait_generator_controller.py

@@ -217,7 +217,11 @@ def update_gait_duration(self, duration):
     def import_gait(self):
         file_name, f = self.view.open_file_dialogue()
 
-        gait = ModifiableSubgait.from_file(self.robot, file_name, self)
+        if file_name != '':
+            gait = ModifiableSubgait.from_file(self.robot, file_name, self)
+        else:
+            gait = None
+
         if gait is None:
             rospy.logwarn('Could not load gait %s', file_name)
             return
@@ -247,7 +251,11 @@ def import_gait(self):
     def import_side_subgait(self, side='previous'):
         file_name, f = self.view.open_file_dialogue()
 
-        subgait = ModifiableSubgait.from_file(self.robot, file_name, self)
+        if file_name != '':
+            subgait = ModifiableSubgait.from_file(self.robot, file_name, self)
+        else:
+            subgait = None
+
         if subgait is None:
             rospy.logwarn('Could not load gait %s', file_name)
             return

march_rqt_gait_generator/test/nosetests/gait_generator_controller_test.py

@@ -180,6 +180,14 @@ def test_import_gait_wrong_gait_file(self):
         with self.assertRaises(FileNotFoundError):
             self.gait_generator_controller.import_gait()
 
+    def test_import_gait_cancel(self):
+        self.gait_generator_view.open_file_dialogue = Mock(return_value=('', None))
+
+        try:
+            self.gait_generator_controller.import_gait()
+        except FileNotFoundError:
+            self.fail('Import gait raised FileNotFoundError')
+
     def test_import_gait(self):
         self.gait_generator_view.open_file_dialogue = Mock(return_value=(self.subgait_path, None))
 
@@ -380,6 +388,14 @@ def test_import_next_subgait(self):
         self.gait_generator_controller.import_side_subgait('next')
         self.assertEqual(self.gait_generator_controller.next_subgait.subgait_name, 'left_swing')
 
+    def test_import_side_subgait_cancel(self):
+        self.gait_generator_view.open_file_dialogue = Mock(return_value=('', None))
+
+        try:
+            self.gait_generator_controller.import_side_subgait('previous')
+        except FileNotFoundError:
+            self.fail('Import side subgait raised FileNotFoundError')
+
     def test_import_previous_subgait_lock_start(self):
         self.gait_generator_view.open_file_dialogue = Mock(return_value=(self.subgait_path, None))