Summary: Added a title so the purpose of the code snippet is clearer
> ==Teaching Emacs to Always Maintain 80 Columns==
When using a window manager that frequently reapportions screen space — such as a tiling window manager — or when in a situation where you are often flipping Emacs in and out of full-screen mode, you might want to train Emacs to maintain a width of 80 characters through each resize event. Though the following code is rudimentary — it would benefit from improvements like a cache of appropriate font sizes instead of recomputing the correct font size afresh with each call — it does maintain at least 80 columns of text across resizing.
;; Maintain at least 80 columns, even when the window is resized (setq maximum-font-height 180) (setq minimum-font-height 60) (setq previous-frame-width 0) (setq window-size-change-functions '((lambda (frame) (if (/= previous-frame-width (frame-width frame)) (let ((trial-size maximum-font-height)) (set-face-attribute 'default frame :height trial-size) (while (and (> trial-size minimum-font-height) (< (frame-width frame) 80)) (setq trial-size (- trial-size 10)) (set-face-attribute 'default frame :height trial-size)) (setq previous-frame-width (frame-width frame)) )))))
This code snippet was originally copied from auto-resize-font.el.