code.delx.au - gnu-emacs-elpa/blob - diff-hl-margin.el

   1 ;;; diff-hl-margin.el --- Highlight buffer changes on margins -*- lexical-binding: t -*-
   2
   3 ;; This file is not part of GNU Emacs.
   4
   5 ;; This file is free software: you can redistribute it and/or modify
   6 ;; it under the terms of the GNU General Public License as published by
   7 ;; the Free Software Foundation, either version 3 of the License, or
   8 ;; (at your option) any later version.
   9
  10 ;; This file is distributed in the hope that it will be useful,
  11 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 ;; GNU General Public License for more details.
  14
  15 ;; You should have received a copy of the GNU General Public License
  16 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  17
  18 ;;; Commentary:
  19
  20 ;; This is a global mode, it modified `diff-hl-mode' to use the margin
  21 ;; instead of the fringe. To toggle, type `M-x diff-hl-margin-mode'.
  22 ;;
  23 ;; Compared to the default behavior, this makes `diff-hl-mode'
  24 ;; indicators show up even when Emacs is running in a terminal.
  25 ;;
  26 ;; On the flip side, the indicators look simpler, and they are
  27 ;; incompatible with `linum-mode' or any other mode that uses the
  28 ;; margin.
  29 ;;
  30 ;; You might want to enable it conditionally in your init file
  31 ;; depending on whether Emacs is running in graphical mode:
  32 ;;
  33 ;; (unless (window-system) (diff-hl-margin-mode))
  34
  35 (require 'diff-hl)
  36 (require 'diff-hl-dired)
  37
  38 (defvar diff-hl-margin-old-highlight-function nil)
  39
  40 (defgroup diff-hl-margin nil
  41   "Highlight buffer changes on margin"
  42   :group 'diff-hl)
  43
  44 (defcustom diff-hl-margin-side 'left
  45   "Which margin to use for indicators."
  46   :type '(choice (const left)
  47                  (const right))
  48   :set (lambda (var value)
  49          (let ((on diff-hl-margin-mode))
  50            (when on (diff-hl-margin-mode -1))
  51            (set-default var value)
  52            (when on (diff-hl-margin-mode 1)))))
  53
  54 ;;;###autoload
  55 (define-minor-mode diff-hl-margin-mode
  56   "Toggle displaying `diff-hl-mode' highlights on the margin."
  57   :lighter "" :global t
  58   (let ((width-var (intern (format "%s-margin-width" diff-hl-margin-side))))
  59     (if diff-hl-margin-mode
  60         (progn
  61           (setq diff-hl-margin-old-highlight-function diff-hl-highlight-function
  62                 diff-hl-highlight-function 'diff-hl-highlight-on-margin)
  63           (set-default width-var 1))
  64       (setq diff-hl-highlight-function diff-hl-margin-old-highlight-function
  65             diff-hl-margin-old-highlight-function nil)
  66       (set-default width-var 0)))
  67   (dolist (buffer (buffer-list))
  68     (with-current-buffer buffer
  69       (cond
  70        (diff-hl-mode
  71         (diff-hl-update))
  72        (diff-hl-dired-mode
  73         (diff-hl-dired-update)))))
  74   (walk-windows (lambda (win) (set-window-buffer win (window-buffer win)))))
  75
  76 (defvar diff-hl-margin-spec-cache
  77   (loop for (type . char) in '((insert . "+") (delete . "-")
  78                                (change . "|") (unknown . "?"))
  79         nconc
  80         (loop for side in '(left right)
  81               collect
  82               (cons (cons type side)
  83                     (propertize
  84                      " " 'display
  85                      `((margin ,(intern (format "%s-margin" side)))
  86                        ,(propertize char 'face
  87                                     (intern (format "diff-hl-%s" type)))))))))
  88
  89 (defun diff-hl-highlight-on-margin (ovl type _shape)
  90   (let ((spec (cdr (assoc (cons type diff-hl-margin-side)
  91                           diff-hl-margin-spec-cache))))
  92     (overlay-put ovl 'before-string spec)))
  93
  94 (provide 'diff-hl-margin)
  95
  96 ;;; diff-hl-margin.el ends here