[GRASS5] g51 v.digit

[Radim Blazek]

Hi,

I started update of v.digit. Currently almost nothing - 
only one tool "new line" exists. But because I modified rasterlib
for this purpose, I would welcome if others, who know more about 
xdriver, could look at it and comment or improve.

As I wanted to enable GUI to break running tools and change parameters
when tool is running, I added function R_set_update_function ()
which sets pointer to function which is regularly called by
running R_get_location_with_pointer/line(). Such function
can break running R_get_location_with* by calling R_set_cancel(1)

Tools in v.digit are started by loop in C part and GUI only sets 
variable to the next tool it wants to start.

Driver is opened/closed for each tool. That enables to resize xdriver
and run other modules while v.digit is runnig but introduces new problems.
I don't know how to get information if xdriver was resized etc.

http://mpa.itc.it/radim/g51/v.digit1.png

Sorry Glynn, I must commit first, otherwise you would tell me, that it
is just hack, and I should wait for a new display architecture. But I cannot
wait 5-10 years :-)

Radim