9.7 Mode Lines

gnus-updated-mode-lines says what buffers should keep their mode lines updated. It is a list of symbols. Supported symbols include group, article, summary, server, browse, and tree. If the corresponding symbol is present, Gnus will keep that mode line updated with information that may be pertinent. If this variable is nil, screen refresh may be quicker.

By default, Gnus displays information on the current article in the mode lines of the summary and article buffers. The information Gnus wishes to display (e.g., the subject of the article) is often longer than the mode lines, and therefore have to be cut off at some point. The gnus-mode-non-string-length variable says how long the other elements on the line is (i.e., the non-info part). If you put additional elements on the mode line (e.g., a clock), you should modify this variable:

(add-hook 'display-time-hook
          (lambda () (setq gnus-mode-non-string-length
                           (+ 21
                              (if line-number-mode 5 0)
                              (if column-number-mode 4 0)
                              (length display-time-string)))))

If this variable is nil (which is the default), the mode line strings won’t be chopped off, and they won’t be padded either. Note that the default is unlikely to be desirable, as even the percentage complete in the buffer may be crowded off the mode line; the user should configure this variable appropriately for her configuration.