Hi GRASS developers,                               9th Oct. 1999

find attached my first steps in tcltk... I used "visual tcl" (vtcl) from
www.neuron.com/stewart/vtcl/
which made writing this rather easy. Because I do not have (yet) a tcl/tk 
introduction, I could not implement all features I wanted to.

This shall be a mapcalculator for TclTkGRASS. Hope we can include
it soon.

Here is what I am suggesting, I expect that several topics can be realized easily
(they will need one or two command extensions). 

  - formula entry needs scrollbar (I didn't understand the scroll command)
  - formula entry should be active for keyboard without clicking into the field 
    (possible ?)
  - the raster maps listing should be integrated directly into the window, no 
    extra window (files to be selectable by mouse: click or doubleclick)
  - for all commands with braces (ex. "if()" ) the cursor should be 
    repositioned *between* the braces. Giving the braces prevents the user 
    from syntax errors, I hope.
  - the backspace button should work
  - "about" button / "syntax helper" button should be own windows with 
    "dismiss" button, "syntax help" button should have scrollbar 
     (contents here: special hints 
    on r.mapcalc not in the manual page)

I would be happy if this calculator (outlook is free for discussion!) 
could be integrated into TclTkGRASS... Comparing to the calculator from 
GPZ (this Motif user interface) I believe that this layout is less 
confusing. GPZ calculator is a mixture of all buttons in one field only.

Have a nice day

   Markus

