Re: O_STATIC implies 'special' justification, is this really necessary?

[Thomas Dickey]

On Wed, Aug 10, 2005 at 09:42:49AM +0200, Frank van Vugt wrote:
> L.S.
> 
> In form/frm_driver.c:183 a define can be found for 
> Justification_Allowed(field). This check also makes sure that a field is 
> O_STATIC. It looks like this check is only used as a guard to 
> Perform/Undo_Justification() calls in frm_driver.c
> 
> However, I'm wondering about the ratio behind this all. Is it really 
> necessary 
> to exclude dynamic fields from say right justification? I understand that 
> there are some layout- and form-traversal-issues to pay attention to, but 
> I've tried and disabled the check for O_STATIC and nothing obvious seems to 
> be failing...
> 
> Am I overlooking something here?

It's not documented in ncurses, but I see it in this paragraph from
caldera's site (which is essentially just the AT&T code):

   If  a field is dynamic, the remainder of the forms library is affected
   in the following way.
...
    2. The field justification will be ignored if the option O_STATIC is
       off.  Currently,  set_field_just  can be used to JUSTIFY_LEFT,
       JUSTIFY_RIGHT, JUSTIFY_CENTER the contents of a one line field. A
       growable  one  line  field  will,  by  definition, grow and scroll
       horizontally  and may contain more data than can be justified. The
       return from field_just will be unchanged.

I don't know why the distinction is made (but it is documented).  Juergen
used the ETI manuals when developing these libraries.

A quick check on Solaris setting O_STATIC off makes demo_forms (using its -d
option) dump core with at the

            field_opts_off(f, O_STATIC);

so I can't see the visual effect (if any) for comparison.

-- 
Thomas E. Dickey <address@hidden>
http://invisible-island.net
ftp://invisible-island.net

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