Can I align items in the modeline to the right?

Question

Given the following modeline configuration:

(setq-default mode-line-format
   (list
    ;; Current buffer name
    "%b "
    ;; Major mode
    "[%m] "
    ;; Modified status
    "[%*] "
    ;; Cursor position
    "Line: %l/%i Column: %c"))

I would like for the last item to appear right-aligned.

Answer 1

Like the answer in the comments, you can do this yourself by writing code to return a nicely spaced string.

Here is a simple way that supports only left and right aligned text applied to your specifications.

;; write a function to do the spacing
(defun simple-mode-line-render (left right)
  "Return a string of `window-width' length containing LEFT, and RIGHT
 aligned respectively."
  (let* ((available-width (- (window-width) (length left) 2)))
    (format (format " %%s %%%ds " available-width) left right)))


;; use the function in conjunction with :eval and format-mode-line in your mode-line-format
(setq mode-line-format
      '((:eval (simple-mode-line-render
                ;; left
                (format-mode-line "%b [%m] [%*]")
                ;; right
                (format-mode-line "Line: %l/%i Column: %c")))))

it ends up looking like this:

Also note, I used your mode-line-format args as you specified, but I believe your are using %i incorrectly, which prints the byte size of the buffer, not the number of lines. You can use something like (line-number-at-pos (point-max)) to get the number of lines in your buffer.

Answer 2

This isn't supported out-of-the-box but the smart-mode-line package does support this. You could either use that package, or if it does more than what you want, extract just the bits that implement the feature you are asking for.