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

   1 ;;; diff-hl.el --- VC diff fringe highlighting -*- lexical-binding: t -*-
   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
  24   (require 'cl)
  25   (require 'vc-git)
  26   (require 'vc-hg))
  27
  28 (defface diff-hl-insert
  29   '((t :inherit diff-added))
  30   "Face used to highlight inserted lines."
  31   :group 'diff-hl)
  32
  33 (defface diff-hl-delete
  34   '((t :inherit diff-removed))
  35   "Face used to highlight deleted lines."
  36   :group 'diff-hl)
  37
  38 (defface diff-hl-change
  39   '((((class color) (min-colors 88) (background light))
  40      :background "#ddddff")
  41     (((class color) (min-colors 88) (background dark))
  42      :background "#333355"))
  43   "Face used to highlight changed lines."
  44   :group 'diff-hl)
  45
  46 (define-fringe-bitmap 'diff-hl-empty [0] 1 1 'center)
  47
  48 (defun diff-hl-changes ()
  49   (let* ((buf-name " *vc-diff-hl* ")
  50          (vc-git-diff-switches nil)
  51          (vc-hg-diff-switches nil)
  52          (vc-diff-switches '("-U0"))
  53          (vc-disable-async-diff t)
  54          (file (buffer-file-name))
  55          (backend (vc-backend file))
  56          res)
  57     (when backend
  58       (vc-call-backend backend 'diff (list file) nil nil buf-name)
  59       (with-current-buffer buf-name
  60         (goto-char (point-min))
  61         (unless (eobp)
  62           (diff-beginning-of-hunk t)
  63           (while (looking-at diff-hunk-header-re-unified)
  64             (let ((line (string-to-number (match-string 3)))
  65                   (len (let ((m (match-string 4)))
  66                          (if m (string-to-number m) 1)))
  67                   (beg (point)))
  68                (diff-end-of-hunk)
  69               (let* ((inserts (diff-count-matches "^\\+" beg (point)))
  70                      (deletes (diff-count-matches "^-" beg (point)))
  71                      (type (cond ((zerop deletes) 'insert)
  72                                  ((zerop inserts) 'delete)
  73                                  (t 'change))))
  74                 (push (list line len type) res)))))))
  75     (nreverse res)))
  76
  77 (eval-and-compile
  78   (dolist (type '(insert delete change))
  79     (let* ((type-str (symbol-name type))
  80            (spec-sym (intern (concat "diff-hl-" type-str "-spec")))
  81            (face-sym (intern (concat "diff-hl-" type-str))))
  82       (eval `(defconst ,spec-sym
  83                ,(propertize " " 'display
  84                             `((left-fringe diff-hl-empty ,face-sym))))))))
  85
  86 (defun diff-hl-update ()
  87   (let ((changes (diff-hl-changes))
  88         (current-line 1))
  89     (save-excursion
  90       (goto-char (point-min))
  91       (mapc (lambda (o) (when (overlay-get o 'diff-hl) (delete-overlay o)))
  92             (overlays-in (point-min) (point-max)))
  93       (dolist (c changes)
  94         (destructuring-bind (line len type) c
  95           (when (eq type 'delete)
  96             (setq len 1)
  97             (incf line))
  98           (forward-line (- line current-line))
  99           (setq current-line line)
 100           (while (plusp len)
 101             (let ((o (make-overlay (point) (line-end-position))))
 102               (overlay-put o 'diff-hl t)
 103               (overlay-put o 'before-string
 104                            (case type
 105                              ('insert diff-hl-insert-spec)
 106                              ('delete diff-hl-delete-spec)
 107                              ('change diff-hl-change-spec)))
 108               (overlay-put o 'modification-hooks '(diff-hl-overlay-modified))
 109               (overlay-put o 'insert-in-front-hooks '(diff-hl-overlay-modified)))
 110             (forward-line 1)
 111             (incf current-line)
 112             (decf len)))))))
 113
 114 (defun diff-hl-overlay-modified (ov after-p _beg _end &optional _length)
 115   ;; Do the simplest possible thing, for now.
 116   (when after-p (delete-overlay ov)))
 117
 118 (defvar diff-hl-timer nil)
 119
 120 (defun diff-hl-edit (_beg _end _len)
 121   ;; DTRT when we've `undo'-ed the buffer into unmodified state.
 122   (when undo-in-progress
 123     (when diff-hl-timer
 124       (cancel-timer diff-hl-timer))
 125     (setq diff-hl-timer
 126           (run-with-idle-timer 0.01 nil #'diff-hl-after-undo (current-buffer)))))
 127
 128 (defun diff-hl-after-undo (buffer)
 129   (with-current-buffer buffer
 130     (unless (buffer-modified-p)
 131       (diff-hl-update))))
 132
 133 ;;;###autoload
 134 (define-minor-mode diff-hl-mode
 135   "Toggle display of VC diff indicators in the left fringe."
 136   :after-hook (diff-hl-update)
 137   (if diff-hl-mode
 138       (progn
 139         (add-hook 'after-save-hook 'diff-hl-update nil t)
 140         (add-hook 'after-change-functions 'diff-hl-edit nil t))
 141     (remove-hook 'after-save-hook 'diff-hl-update t)
 142     (remove-hook 'after-change-functions 'diff-hl-edit t)))
 143
 144 (defun turn-on-diff-hl-mode ()
 145   (when (buffer-file-name)
 146     (diff-hl-mode 1)))
 147
 148 ;;;###autoload
 149 (define-globalized-minor-mode global-diff-hl-mode diff-hl-mode
 150   turn-on-diff-hl-mode)
 151
 152 (provide 'diff-hl)