Tcl - ASCII Line graphics in tcl

Author

ASCII Line graphics in tcl

GizmoGorilla

2004-10-20, 8:57 pm

I have a text report generator I've written in tcl
for a database I have and Im trying to make the
reports look sharp by creating borders. I dont want
to use characters like | + _ for my boxes. Is it possible
to access the alternate character set that has all the box
drawing characters. Im currently using a listbox to
display my text. If this isnt possible are there any
other possibilities to spruce up my reports with borders
without getting bogged down in graphics.

Thanx
GizmoGorilla

Erik Leunissen

2004-10-20, 8:57 pm

See http://www.unicode.org/charts/PDF/U2500.pdf
for the codes of the unicode characters you need.

Prefix them with a leading "\u" and use them in your tcl I/O commands, like:

puts \u250C\u2500\u2510

This example draws the upper part of the smallest ascii box one can
imagine. I leave it up to you to draw the other half.

HTH,

Erik Leunissen
=============

GizmoGorilla wrote:
> I have a text report generator I've written in tcl
> for a database I have and Im trying to make the
> reports look sharp by creating borders. I dont want
> to use characters like | + _ for my boxes. Is it possible
> to access the alternate character set that has all the box
> drawing characters. Im currently using a listbox to
> display my text. If this isnt possible are there any
> other possibilities to spruce up my reports with borders
> without getting bogged down in graphics.
>
> Thanx
> GizmoGorilla
>

--
leunissen@ nl | Merge the left part of these two lines into one,
e. hccnet. | respecting a character's position in a line.

GizmoGorilla

2004-10-21, 4:04 pm

Erik Leunissen wrote:
> See http://www.unicode.org/charts/PDF/U2500.pdf
> for the codes of the unicode characters you need.
>
> Prefix them with a leading "\u" and use them in your tcl I/O commands,
> like:
>
> puts \u250C\u2500\u2510
>
> This example draws the upper part of the smallest ascii box one can
> imagine. I leave it up to you to draw the other half.
>
> HTH,
>
> Erik Leunissen
> =============

Erik,
Thanks for your response. The chart is great.
Unfortunately I had no success. When I use the
line you suggest I get ??? on the screen.
I've also tried using hex and binary, in
quotes & without. I've tried sending the escape
sequence to select the alternate keys and still
nothing.(I realize that thats a terminal "thing")
Same result if sending to either the
list box as text or to a shell (im using unix).
Surely there must be a way to access the box
graphics characters.

Thanx
Norm

Bruce Hartweg

2004-10-21, 4:04 pm

GizmoGorilla wrote:
> Erik Leunissen wrote:
>
>
>
> Erik,
> Thanks for your response. The chart is great.
> Unfortunately I had no success. When I use the
> line you suggest I get ??? on the screen.
> I've also tried using hex and binary, in
> quotes & without. I've tried sending the escape
> sequence to select the alternate keys and still
> nothing.(I realize that thats a terminal "thing")
> Same result if sending to either the
> list box as text or to a shell (im using unix).
> Surely there must be a way to access the box
> graphics characters.
>
to use the unicode solution, you need to use a font
that supports it.

Bruce

Benjamin Riefenstahl

2004-10-21, 4:04 pm

Hi Norm,

GizmoGorilla writes:
> Subject: Re: ASCII Line graphics in tcl

<nitpick>
"ASCII" doesn't have line drawing characters. "ASCII line graphics" is
the stuff that you want to avoid (using "+", "-", "|" etc). What you
want (if I understand you right) is to use the *non-ASCII* capabilities
of your terminal.
</nitpick>

> When I use the line you suggest I get ??? on the screen. I've also
> tried using hex and binary, in quotes & without. I've tried sending
> the escape sequence to select the alternate keys and still
> nothing.(I realize that thats a terminal "thing") Same result if
> sending to either the list box as text or to a shell (im using
> unix). Surely there must be a way to access the box graphics
> characters.

I don't have enough time right now to test this, so here are just a
few ideas for now:

fconfigure stdout -encoding name-of-the-encoding

will cause [puts] to convert the internal Tcl string representation to
the encoding that is given. This will probably default to iso8859-1
on your system or to whatever your LANG environment variable
indicates.

[puts] will not send the necessary escape sequences to change the
terminal charset, so you will need to do that yourself. So I would
try something along the lines:

# Some global constants
set escape_alt_charset_on "..."
set escape_alt_charset_off "..."
set terminal_default_encoding [fconfigure stdout -encoding]
set terminal_alt_charset_encoding "..."

proc alt_charset_on {} {
puts -nonewline $::escape_alt_charset_on
fconfigure stdout -encoding $::terminal_alt_charset_encoding
}
proc alt_charset_off {} {
puts -nonewline $::escape_alt_charset_off
fconfigure stdout -encoding $::terminal_default_encoding
}

To complete this you will have to research which escape sequences are
needed and which encoding is actually used by the alternate charset
configuration.

benny

GizmoGorilla

2004-10-21, 4:04 pm

Bruce Hartweg wrote:

> to use the unicode solution, you need to use a font
> that supports it.

Aha!
Yes, I forgot about that. I've done this a few years
ago in assembler and remember that only some fonts
had the line graphics. Memory is ! what it used 2 B.
Thanks, I'll check it out

Norm

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