bh: thuban/Thuban/UI viewport.py,1.20,1.21

[cvs@intevation.de]

Author: bh

Update of /thubanrepository/thuban/Thuban/UI
In directory doto:/tmp/cvs-serv22461/Thuban/UI

Modified Files:
	viewport.py 
Log Message:
(ViewPort.set_view_transform): Handle
ZeroDivisionError exceptions.  I don't know when they happen
exactly.  It probably happens when the projections aren't set
properly.


Index: viewport.py
===================================================================
RCS file: /thubanrepository/thuban/Thuban/UI/viewport.py,v
retrieving revision 1.20
retrieving revision 1.21
diff -u -d -r1.20 -r1.21
--- viewport.py	24 Jan 2005 11:19:53 -0000	1.20
+++ viewport.py	5 Jul 2005 16:00:47 -0000	1.21
@@ -15,6 +15,7 @@
 # $Source$
 # $Id$
 
+import sys
 from math import hypot
 
 from wxproj import point_in_polygon_shape, shape_centroid
@@ -410,8 +411,17 @@
 
         # The window's center in projected coordinates assuming the new
         # scale/offset
-        pcenterx = (wwidth/2 - offset[0]) / scale
-        pcentery = (offset[1] - wheight/2) / scale
+        try:
+            pcenterx = (wwidth/2 - offset[0]) / scale
+            pcentery = (offset[1] - wheight/2) / scale
+        except ZeroDivisionError:
+            # scale was zero.  Probably a problem with the projections.
+            # printing an error message and return immediately. The user
+            # will hopefully be informed by the UI which displays a
+            # message for at least some of the projection problems.
+            print >>sys.stderr, "ViewPort.set_view_transform:", \
+                  "ZeroDivisionError, scale =", repr(scale)
+            return
 
         min_scale, max_scale = self.calc_min_max_scales(scale)