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

   1 ;; Author:   Dmitry Gutov <dgutov@yandex.ru>
   2 ;; URL:      https://github.com/dgutov/diff-hl
   3
   4 ;; This file is not part of GNU Emacs.
   5
   6 ;; This file is free software: you can redistribute it and/or modify
   7 ;; it under the terms of the GNU General Public License as published by
   8 ;; the Free Software Foundation, either version 3 of the License, or
   9 ;; (at your option) any later version.
  10
  11 ;; This file is distributed in the hope that it will be useful,
  12 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;; GNU General Public License for more details.
  15
  16 ;; You should have received a copy of the GNU General Public License
  17 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 ;;; Commentary:
  20
  21 ;; Toggle in the current buffer with `M-x diff-hl-amend-mode'.
  22 ;; Toggle in all buffers with `M-x global-diff-hl-amend-mode'.
  23
  24 ;;; Code:
  25
  26 (require 'diff-hl)
  27
  28 ;;;###autoload
  29 (define-minor-mode diff-hl-amend-mode
  30   "Show changes against the second-last revision in `diff-hl-mode'.
  31 Most useful with VCSes that support rewriting local commits, and
  32 'amending' the most recent one in particular.
  33 Currently only supports Git, Mercurial and Bazaar."
  34   :lighter " Amend"
  35   (if diff-hl-amend-mode
  36       (progn
  37         (if vc-mode
  38             (diff-hl-amend-setup)
  39           (add-hook 'find-file-hook 'diff-hl-amend-setup nil t))
  40         (add-hook 'after-revert-hook 'diff-hl-amend-setup nil t))
  41     (remove-hook 'find-file-hook 'diff-hl-amend-setup t)
  42     (remove-hook 'after-revert-hook 'diff-hl-amend-setup t)
  43     (setq-local diff-hl-reference-revision nil))
  44   (when diff-hl-mode
  45     (diff-hl-update)))
  46
  47 (defun diff-hl-amend-setup ()
  48   (let ((backend (vc-backend buffer-file-name)))
  49     (when backend
  50       (setq-local diff-hl-reference-revision
  51                   (cl-case backend
  52                     (Git
  53                      "HEAD^")
  54                     (Hg
  55                      "-2")
  56                     (Bzr
  57                      "revno:-2"))))))
  58
  59 ;;;###autoload
  60 (define-globalized-minor-mode global-diff-hl-amend-mode diff-hl-amend-mode
  61   turn-on-diff-hl-amend-mode)
  62
  63 (defun turn-on-diff-hl-amend-mode ()
  64   "Turn on `diff-hl-amend-mode' in a buffer if appropriate."
  65   (and buffer-file-name (diff-hl-amend-mode 1)))
  66
  67 (provide 'diff-hl-amend)
  68
  69 ;;; diff-hl-amend.el ends here