Translatable strings in .h file -- best way to resolve?

[Mike Alexander]

--On March 16, 2010 10:17:37 AM +0100 Christian Stimming 
<stimming at tuhh.de> wrote:

> Zitat von Jeff Kletsky <gnucash at allycomm.com>:
>> #define ACCOUNT_OPTIONS_SECTION "Accounts"
>> #define TRADING_ACCOUNTS_OPTION "Trading Accounts"
>>
>> Presently, make-gnucash-potfiles.in does not look at .h files for
>> translatable strings, so even after adding
>> #include <glib/gi18n.h>
>> and marking the strings, they don't make it into POTFILES.in
>>
>> What approach is recommended for resolving this?
>>
>> * Add an exception to make-gnucash-potfiles.in
>
> Yes.
>
>> * Use _(ACCOUNTS_OPTIONS_SECTION) and don't translate the raw define
>
> Yes. In the #define lines, the strings should be marked with the N_(
> ... ) macro, so they are still just a const char* literal for the
> compiler's point of view, but they make it into gnucash.pot:
>
> #include <glib/gi18n.h>
> #define ACCOUNT_OPTIONS_SECTION N_("Accounts")
>
> Subsequently, in places where the defines are being used for
> human-visible display, they need to be translated writing
> _(ACCOUNTS_OPTIONS_SECTION).
>
>> * Change .h to .c and leave people wondering why a .c file is being
>> #include-d
>
> No.
>

This is my fault.  These #defines are used in two places.  One is 
qofbook.c where they are used to access the slot holding the value of 
this option.  These should, of course, not be translated.  The other is 
in business-prefs.scm where they are used as the section and name 
parameters to gnc:make-simple-boolean-option.  The other calls to 
gnc:make-...-option in this file use (N_ ...) for the name and section 
parameters.  These parameters are used for both slot access and for the 
UI.  There must be some special magic to cause them to be translated 
for the one case and not the other.

I think the correct fix is to leave the #defines alone (the C code only 
uses these for slot access) and change the two lines in 
business-utils.scm to read

(define gnc:*book-label* (N_ ACCOUNT-OPTIONS-SECTION))
(define gnc:*trading-accounts* (N_ TRADING-ACCOUNTS-OPTION))

Unfortunately I've been out of town for the last month and I need to do 
a bunch of updating and building before I can test this fix.  However 
it makes things consistent with the other constants defined in 
business-utils.scm and used in business-prefs.scm so it may be ok.

It would probably also be ok to include the N_(...) on the #defines but 
doing it like I describe would be more consistent with the other 
strings used in business-prefs.scm.

I think things do mostly work the way they are, except that the strings 
probably aren't marked for translation as they should be.  When I added 
this code I tested it by adding a fake translation for "Trading 
Accounts" and it showed up in the UI.

This is all very confusing to me.  All of the calls to 
gnc:make-...-option use (N_ ...) for the section, name, and description 
parameters, but somehow they get translated anyway.  I think I tracked 
this down once, but I've forgotten how it works now.

      Mike