Re: Custom mode-line format (bug)

[Miguel Guedes]

Hi Michael,

On Wed, 20 Mar 2013 18:07:58 +0100, Michael Heerdegen wrote:

> No, that's not a bug.  You set `mode-line-format' to a already formatted
> (calculated) mode-line, which is just a (constant) string.  Note that
> 
>  (format-mode-line mode-line-format 'mode-line-custom-warning-face)
> 
> is evaluated at load time.
> 
> What you want is something like this:
> 
> (defun root-file-warning ()
>   (when (string-match "^/su\\(do\\)?:" default-directory)
>     (setq mode-line-format
>           `(:propertize ,mode-line-format face
>           mode-line-custom-warning-face))
>     (server-start-timed)
>     ))
> 
> But maybe it's better (cleaner) to use face-remapping for that purpose,
> instead of manipulating the mode-line:
> 
> (defun root-file-warning ()
>   (when (string-match "^/su\\(do\\)?:" default-directory)
>     (face-remap-add-relative
>      'mode-line '(:background "dark red" :foreground "white"))
>     (server-start-timed)))
> 
> You could as well remap the `mode-line-inactive' face so that the
> mode-line looks different as well when the according window is not
> selected.

This solution of yours works absolutely beautiful; also thanks for the 
explanation why it wasn't working.

Here's what I came up with in the end (added mode-line-inactive as per 
your recommendation):

(defun root-file-warning ()
  (when (string-match "^/su\\(do\\)?:" default-directory)
    (face-remap-add-relative
     'mode-line
     '(:background "red3" :foreground "white"))
    (face-remap-add-relative
     'mode-line-inactive
     '(:background "red4" :foreground "dark gray"))
  )

Thanks for your help.