Centre Emacs buffer within window

Question

I wrap all my code at 80 columns, and there are times where the Emacs window is wider than 80 columns and there is a lot of unused whitespace on the right side.

I would

Answer 1

Here is a function which should do what you want, using margins instead of fringes (since I tend to display buffer boundaries in the fringe and I find it becomes ugly if the fringe is too large).

(defun my/center (width)
  (interactive "nBuffer width: ")
  (let* ((adj          (- (window-text-width)
                          width))
         (total-margin (+ adj
                          left-margin-width
                          right-margin-width)))
    (setq left-margin-width  (/ total-margin 2))
    (setq right-margin-width (- total-margin left-margin-width)))
  (set-window-buffer (selected-window) (current-buffer)))