diff -r d51af006fa6b -r 64d8f52bc8c8 dialogs/SFCDivergenceDialog.py
--- a/dialogs/SFCDivergenceDialog.py	Fri Aug 11 15:18:19 2017 +0300
+++ b/dialogs/SFCDivergenceDialog.py	Mon Aug 14 19:13:01 2017 +0300
@@ -40,7 +40,7 @@
 """
 
 class SFCDivergenceDialog(BlockPreviewDialog):
-    
+
     def __init__(self, parent, controller, tagname, poss_div_types = None):
         """
         Constructor
@@ -51,14 +51,14 @@
         """
         BlockPreviewDialog.__init__(self, parent, controller, tagname,
               title=_('Create a new divergence or convergence'))
-        
+
         # Init common sizers
         self._init_sizers(2, 0, 7, None, 2, 1)
-        
+
         # Create label for divergence type
         type_label = wx.StaticText(self, label=_('Type:'))
         self.LeftGridSizer.AddWindow(type_label, flag=wx.GROW)
-        
+
         # Create radio buttons for selecting divergence type
         divergence_buttons = [
             (SELECTION_DIVERGENCE, _('Selection Divergence')),
@@ -75,7 +75,7 @@
         first = True
         focusbtn = None
         for type, label in poss_div_btns:
-            radio_button = wx.RadioButton(self, label=label, 
+            radio_button = wx.RadioButton(self, label=label,
                   style=(wx.RB_GROUP if first else 0))
             radio_button.SetValue(first)
             self.Bind(wx.EVT_RADIOBUTTON, self.OnTypeChanged, radio_button)
@@ -85,29 +85,29 @@
             first = False
 
         # Create label for number of divergence sequences
-        sequences_label = wx.StaticText(self, 
+        sequences_label = wx.StaticText(self,
               label=_('Number of sequences:'))
         self.LeftGridSizer.AddWindow(sequences_label, flag=wx.GROW)
-        
+
         # Create spin control for defining number of divergence sequences
         self.Sequences = wx.SpinCtrl(self, min=2, max=20, initial=2)
         self.Bind(wx.EVT_SPINCTRL, self.OnSequencesChanged, self.Sequences)
         self.LeftGridSizer.AddWindow(self.Sequences, flag=wx.GROW)
-        
+
         # Add preview panel and associated label to sizers
         self.RightGridSizer.AddWindow(self.PreviewLabel, flag=wx.GROW)
         self.RightGridSizer.AddWindow(self.Preview, flag=wx.GROW)
-        
+
         # Add buttons sizer to sizers
-        self.MainSizer.AddSizer(self.ButtonSizer, border=20, 
+        self.MainSizer.AddSizer(self.ButtonSizer, border=20,
               flag=wx.ALIGN_RIGHT|wx.BOTTOM|wx.LEFT|wx.RIGHT)
-        
+
         self.Fit()
 
         # Selection divergence radio button is default control having keyboard
         # focus
         self.TypeRadioButtons[focusbtn].SetFocus()
-    
+
     def GetMinElementSize(self):
         """
         Get minimal graphic element size
@@ -115,7 +115,7 @@
         element defined
         """
         return self.Element.GetMinSize(True)
-    
+
     def GetDivergenceType(self):
         """
         Return type selected for SFC divergence
@@ -127,7 +127,7 @@
             if control.GetValue():
                 return type
         return None
-    
+
     def GetValues(self):
         """
         Set default SFC divergence parameters
@@ -151,17 +151,16 @@
         """
         self.RefreshPreview()
         event.Skip()
-        
+
     def RefreshPreview(self):
         """
         Refresh preview panel of graphic element
         Override BlockPreviewDialog function
         """
         # Set graphic element displayed, creating a SFC divergence
-        self.Element = SFC_Divergence(self.Preview, 
-                                      self.GetDivergenceType(), 
+        self.Element = SFC_Divergence(self.Preview,
+                                      self.GetDivergenceType(),
                                       self.Sequences.GetValue())
-        
+
         # Call BlockPreviewDialog function
         BlockPreviewDialog.RefreshPreview(self)
-