[GRASS-user] GUI freeze when trying to change legend

[Michael Barton]

On Sep 29, 2009, at 5:14 AM, grass-user-request at lists.osgeo.org wrote:

> Date: Tue, 29 Sep 2009 07:07:24 -0400
> From: Michael Denslow <michael.denslow at gmail.com>
> Subject: [GRASS-user] GUI freeze when trying to change legend
> To: grass-user at lists.osgeo.org
> Message-ID:
>        <b440a3f80909290407g61ffa161iaa933697ec9d1afb at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Dear Grass,
>
> I am having a problem when I try to change the legend for my raster
> file using to GUI. This happens even if I select a new legend to add.
> As soon as I select the raster map from the list Grass freezes for
> several minutes.
>
> Perhaps it is a problem with the raster file or the rules file,
> however it runs fine when I run the command in the terminal. I would
> like to do this in the GUI since I am not sure how to do all of my map
> resizing and saving as .tif from the command line.
>
> Can someone please advise me on this?
>
> I am using Grass 6.4 with standard GUI (not Python)
> System is Mac OS 10.6.1
>
> Thanks in advance for your time,
>
> Michael


  I see that you are using Snow Leopard, which has Python 2.5.1 and  
2.6 on it. It can also have a couple different wxpython versions.  
William Kyngesburye has worked out special instructions for compiling  
on Snow Leopard.

If you are not using a recently compiled binary (after mid-September),  
you will have problems.

My guess is that this is related to ticket: http://trac.osgeo.org/grass/ticket/753 
. This is caused when you compile GRASS with more than one version of  
python on your Mac. In these circumstances, there is an error in a  
display widget (PseudoDC). The whole issue is complicated but I can  
explain more if you are interested in the intricacies of the code.

The fixes are to either
1) find the second version of Python and any vestiges of a second  
wxpython and delete them (sometimes harder than it seems, and  
especially complicated with Snow Leopard with needs 2 official Python  
versions), make distclean, and recompile. Or
2) bundle wxpython with GRASS.

The second option guarantees that you are running with the version of  
wxpython that you compiled with and that all parts of GRASS are using  
the same wxpython. I'm recommending bundling wxpython with all Mac  
binaries to avoid this and other problems.

Michael