diff -r da5f1fa46f2b -r fb73a6b6622d controls/CustomStyledTextCtrl.py
--- a/controls/CustomStyledTextCtrl.py	Thu Oct 19 10:57:35 2017 +0300
+++ b/controls/CustomStyledTextCtrl.py	Thu Oct 19 11:03:03 2017 +0300
@@ -97,10 +97,9 @@
             if not event.Dragging():
                 x, _y = event.GetPosition()
                 margin_width = reduce(
-                        lambda x, y: x + y,
-                        [self.GetMarginWidth(i)
-                         for i in xrange(3)],
-                        0)
+                    lambda x, y: x + y,
+                    [self.GetMarginWidth(i) for i in xrange(3)],
+                    0)
                 if x <= margin_width:
                     self.SetCursor(wx.StockCursor(wx.CURSOR_ARROW))
                 else: