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

   1 ;;; diff-hl.el --- VC diff highlighting in the buffer window
   2
   3 ;; Author:   Dmitry Gutov <dgutov@yandex.ru>
   4 ;; Keywords: vc, diff
   5
   6 ;; This file is not part of GNU Emacs.
   7
   8 ;; This file is free software: you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation, either version 3 of the License, or
  11 ;; (at your option) any later version.
  12
  13 ;; This file is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 (require 'diff-mode)
  22 (require 'vc)
  23 (eval-when-compile (require 'cl))
  24
  25 (defface diff-hl-insert
  26   '((t :inherit diff-added))
  27   "Face used to highlight inserted lines."
  28   :group 'diff-hl)
  29
  30 (defface diff-hl-delete
  31   '((t :inherit diff-removed))
  32   "Face used to highlight deleted lines."
  33   :group 'diff-hl)
  34
  35 (defface diff-hl-change
  36   '((((class color) (min-colors 88) (background light))
  37      :background "#ddddff")
  38     (((class color) (min-colors 88) (background dark))
  39      :background "#333355"))
  40   "Face used to highlight changed lines."
  41   :group 'diff-hl)
  42
  43 (define-fringe-bitmap 'diff-hl-empty [0] 1 1 'center)
  44
  45 (defun diff-hl-changes ()
  46   (let* ((buf-name " *vc-diff-hl* ")
  47          (vc-git-diff-switches nil)
  48          (vc-hg-diff-switches nil)
  49          (vc-diff-switches '("-U0"))
  50          (vc-disable-async-diff t)
  51          (file (buffer-file-name))
  52          (backend (vc-backend file))
  53          res)
  54     (when backend
  55       (vc-call-backend backend 'diff (list file) nil nil buf-name)
  56       (with-current-buffer buf-name
  57         (goto-char (point-min))
  58         (unless (eobp)
  59           (diff-beginning-of-hunk t)
  60           (while (looking-at diff-hunk-header-re-unified)
  61             (let ((line (string-to-number (match-string 3)))
  62                   (len (let ((m (match-string 4)))
  63                          (if m (string-to-number m) 1)))
  64                   (beg (point)))
  65                (diff-end-of-hunk)
  66               (let* ((inserts (diff-count-matches "^\\+" beg (point)))
  67                      (deletes (diff-count-matches "^-" beg (point)))
  68                      (type (cond ((zerop deletes) 'insert)
  69                                  ((zerop inserts) 'delete)
  70                                  (t 'change))))
  71                 (push (list line len type) res)))))))
  72     (nreverse res)))
  73
  74 (eval-and-compile
  75   (dolist (type '(insert delete change))
  76     (let* ((type-str (symbol-name type))
  77            (spec-sym (intern (concat "diff-hl-" type-str "-spec")))
  78            (face-sym (intern (concat "diff-hl-" type-str))))
  79       (eval `(defconst ,spec-sym
  80                ,(propertize " " 'display
  81                             `((left-fringe diff-hl-empty ,face-sym))))))))
  82
  83 (defun diff-hl-update ()
  84   (let ((changes (diff-hl-changes))
  85         (current-line 1))
  86     (save-excursion
  87       (goto-char (point-min))
  88       (mapc (lambda (o) (when (overlay-get o 'diff-hl) (delete-overlay o)))
  89             (overlays-in (point-min) (point-max)))
  90       (dolist (c changes)
  91         (destructuring-bind (line len type) c
  92           (when (eq type 'delete)
  93             (setq len 1)
  94             (incf line))
  95           (forward-line (- line current-line))
  96           (setq current-line line)
  97           (while (plusp len)
  98             (let ((o (make-overlay (point) (line-end-position))))
  99               (overlay-put o 'diff-hl t)
 100               (overlay-put o 'before-string
 101                            (case type
 102                              ('insert diff-hl-insert-spec)
 103                              ('delete diff-hl-delete-spec)
 104                              ('change diff-hl-change-spec)))
 105               (overlay-put o 'modification-hooks '(diff-hl-overlay-modified))
 106               (overlay-put o 'insert-in-front-hooks '(diff-hl-overlay-modified)))
 107             (forward-line 1)
 108             (incf current-line)
 109             (decf len)))))))
 110
 111 (defun diff-hl-overlay-modified (ov after-p beg end &optional length)
 112   ;; Do the simplest possible thing, for now.
 113   (when after-p (delete-overlay ov)))
 114
 115 (defvar diff-hl-timer nil)
 116
 117 (defun diff-hl-edit (beg end len)
 118   ;; DTRT when we've `undo'-ed the buffer into unmodified state.
 119   (when undo-in-progress
 120     (when diff-hl-timer
 121       (cancel-timer diff-hl-timer))
 122     (setq diff-hl-timer
 123           (run-with-idle-timer 0.01 nil #'diff-hl-after-undo (current-buffer)))))
 124
 125 (defun diff-hl-after-undo (buffer)
 126   (with-current-buffer buffer
 127     (unless (buffer-modified-p)
 128       (diff-hl-update))))
 129
 130 ;;;###autoload
 131 (define-minor-mode diff-hl-mode
 132   "Toggle display of VC diff indicators in the left fringe."
 133   :after-hook (diff-hl-update)
 134   (if diff-hl-mode
 135       (progn
 136         (add-hook 'after-save-hook 'diff-hl-update nil t)
 137         (add-hook 'after-change-functions 'diff-hl-edit nil t))
 138     (remove-hook 'after-save-hook 'diff-hl-update t)
 139     (remove-hook 'after-change-functions 'diff-hl-edit t)))
 140
 141 (defun turn-on-diff-hl-mode ()
 142   (when (buffer-file-name)
 143     (diff-hl-mode 1)))
 144
 145 ;;;###autoload
 146 (define-globalized-minor-mode global-diff-hl-mode diff-hl-mode
 147   turn-on-diff-hl-mode)
 148
 149 (provide 'diff-hl)