Re: Operation of format-mode-line

[Michael Heerdegen via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org>]

Heime <heimeborgia@protonmail.com> writes:

> Meaning that if a buffer name length exceeds the width, the full
> buffer name is still printed.  Something must be wrong because it
> should not be this hard to change this minor buffer name appearance.

I think I see now one reason of your confusion:

| In any construct except ‘%%’, you can add a decimal integer after the
| ‘%’ to specify a minimum field width.

See (info "(elisp) %-Constructs").  Not the maximum width.  Ok?

To truncate a string, use `truncate-string-to-width'.  Or, if you want
to rely on mode-line special constructs,

| ‘(WIDTH REST...)’
|      A list whose first element is an integer specifies truncation or
|      padding of the results of REST.  The remaining elements REST are
|      processed recursively as mode line constructs and concatenated
|      together.  When WIDTH is positive, the result is space filled on
|      the right if its width is less than WIDTH.  When WIDTH is negative,
|      the result is truncated on the right to −WIDTH columns if its width
|      exceeds −WIDTH.

See (info "(elisp) Mode Line Data").

I guess it could be less confusing and annoying for you to have a look
at those parts of the manual.


Michael.