;;; move-border.el --- Move border to resize windows
;; Copyright (C) Unknown

;; Author: Unknown
;; Maintainer: Guillaume Gelin <contact@ramnes.eu>
;; Created 5 sep 2008
;; Keywords: window border
;; Homepage: https://github.com/ramnes/move-border

;; This file is not part of GNU Emacs.

;;; Commentary:

;; Add commands to move border
;; instead of using the built-in
;; window resizing functions

;;; Code:

(defun xor (b1 b2)
  (or (and b1 b2)
      (and (not b1) (not b2))))

(defun move-border-left-or-right (arg dir)
  "General function covering move-border-left and move-border-right. If DIR is
     t, then move left, otherwise move right."
  (interactive)
  (if (null arg) (setq arg 3))
  (let ((left-edge (nth 0 (window-edges))))
    (if (xor (= left-edge 0) dir)
        (shrink-window arg t)
      (enlarge-window arg t))))

(defun move-border-up-or-down (arg dir)
  "General function covering move-border-up and move-border-down. If DIR is
     t, then move up, otherwise move down."
  (interactive)
  (if (null arg) (setq arg 3))
  (let ((top-edge (nth 1 (window-edges))))
    (if (xor (= top-edge 0) dir)
        (shrink-window arg nil)
      (enlarge-window arg nil))))

(defun move-border-left (arg)
  (interactive "P")
  (move-border-left-or-right arg t))

(defun move-border-right (arg)
  (interactive "P")
  (move-border-left-or-right arg nil))

(defun move-border-up (arg)
  (interactive "P")
  (move-border-up-or-down arg t))

(defun move-border-down (arg)
  (interactive "P")
  (move-border-up-or-down arg nil))

(provide 'move-border)

;;; move-border.el ends here