[GRASS-dev] Re: helpful error messages

Michael Barton michael.barton at asu.edu
Sun Apr 29 19:49:49 EDT 2007

Thanks for the input.

The TclTk error codes are generated by TclTk. They are generally very
verbose, though that is not always helpful. But they aren't too bad as error
codes go, since they are in english rather than a numeric code and they
indicate where the error occurred.

Sometimes the TclTk errors are actually generated by a GRASS or system
problem. I'm trying to add more TclTk error traps (catch clauses) that will
print these to the terminal when they happen. They may or may not be more
interpretable, but at least they will be available.

In a few cases where we can anticipate a possible user error and know what
causes it, I can build in a message box that explains the problem. There are
a number of these scattered throughout the code, though not as many as the
catch clauses I'm adding, because it is very difficult to know in advance
what is wrong in order to generate a non-TclTk/GRASS/system error message.


On 4/29/07 3:15 PM, "Gerald Nelson" <gnelson at uiuc.edu> wrote:

> I don't often get a chance to have input to hard core code development so this
> may be a naive request, but...
> can I enter a request for error messages generally, and from the catch code
> being discussed in particular, that are verbose and provide some indication of
> the likely source of the problem. Or when the source could be a variety of
> things, a list of possible problems?
> Thanks, 
> Jerry
> ---- Original message ----
>> Date: Sun, 29 Apr 2007 23:01:15 +0100
>> From: Glynn Clements <glynn at gclements.plus.com>
>> Subject: Re: [GRASS-dev] figuring out fonts - part 2
>> To: Michael Barton <michael.barton at asu.edu>
>> Cc: GRASS developers list <grass-dev at grass.itc.it>
>> Michael Barton wrote:
>>> It is a good thing that GRASS has a set of fonts that can be guaranteed to
>>> be present, regardless of the system. These are the venerable stroke fonts.
>>> But these fonts are ugly and hard to read. Romans just doesn¹t stand out
>>> well in a scale or legend, for example, unless against a white background
>>> and even then it is not clear at a distance for presentations.
>>> So here is a question. Can GRASS ship with a better set of fonts? Can it
>>> come with a minimal TrueType set, for example, that could be guaranteed
>>> present regardless of the system? Or is this technically not realistically
>>> feasible?
>> Support for TrueType fonts requires the FreeType library, which is
>> currently an optional dependency.
>> That aside, most people will already have the Luxi font from the X.org
>> packages.
>> -- 
>> Glynn Clements <glynn at gclements.plus.com>
>> _______________________________________________
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> Gerald Nelson
> Professor, Dept. of Agricultural and Consumer Economics
> University of Illinois, Urbana-Champaign
> office: 217-333-6465
> cell: 217-390-7888
> 315 Mumford Hall
> 1301 W. Gregory
> Urbana, IL 61801

Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics & Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton

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