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     (diff-hl-remove-overlays)
  90     (save-excursion
  91       (goto-char (point-min))
  92       (dolist (c changes)
  93         (destructuring-bind (line len type) c
  94           (when (eq type 'delete)
  95             (setq len 1)
  96             (incf line))
  97           (forward-line (- line current-line))
  98           (setq current-line line)
  99           (while (plusp len)
 100             (let ((o (make-overlay (point) (line-end-position))))
 101               (overlay-put o 'diff-hl t)
 102               (overlay-put o 'before-string
 103                            (case type
 104                              ('insert diff-hl-insert-spec)
 105                              ('delete diff-hl-delete-spec)
 106                              ('change diff-hl-change-spec)))
 107               (overlay-put o 'modification-hooks '(diff-hl-overlay-modified))
 108               (overlay-put o 'insert-in-front-hooks '(diff-hl-overlay-modified)))
 109             (forward-line 1)
 110             (incf current-line)
 111             (decf len)))))))
 112
 113 (defun diff-hl-remove-overlays ()
 114   (dolist (o (overlays-in (point-min) (point-max)))
 115     (when (overlay-get o 'diff-hl) (delete-overlay o))))
 116
 117 (defun diff-hl-overlay-modified (ov after-p _beg _end &optional _length)
 118   ;; Do the simplest possible thing, for now.
 119   (when after-p (delete-overlay ov)))
 120
 121 (defvar diff-hl-timer nil)
 122
 123 (defun diff-hl-edit (_beg _end _len)
 124   ;; DTRT when we've `undo'-ed the buffer into unmodified state.
 125   (when undo-in-progress
 126     (when diff-hl-timer
 127       (cancel-timer diff-hl-timer))
 128     (setq diff-hl-timer
 129           (run-with-idle-timer 0.01 nil #'diff-hl-after-undo (current-buffer)))))
 130
 131 (defun diff-hl-after-undo (buffer)
 132   (with-current-buffer buffer
 133     (unless (buffer-modified-p)
 134       (diff-hl-update))))
 135
 136 ;;;###autoload
 137 (define-minor-mode diff-hl-mode
 138   "Toggle display of VC diff indicators in the left fringe."
 139   :lighter ""
 140   (if diff-hl-mode
 141       (progn
 142         (add-hook 'after-save-hook 'diff-hl-update nil t)
 143         (add-hook 'after-change-functions 'diff-hl-edit nil t)
 144         (if vc-mode
 145             (diff-hl-update)
 146           (add-hook 'find-file-hook 'diff-hl-update t t)))
 147     (remove-hook 'after-save-hook 'diff-hl-update t)
 148     (remove-hook 'after-change-functions 'diff-hl-edit t)
 149     (remove-hook 'find-file-hook 'diff-hl-update t)
 150     (diff-hl-remove-overlays)))
 151
 152 (defun turn-on-diff-hl-mode ()
 153   ;; FIXME: Why is this called twice for each buffer?
 154   ;; Isn't fundamental-mode supposed to not run any hooks?
 155   (when (and buffer-file-name (not (eq major-mode (default-value 'major-mode))))
 156     (diff-hl-mode 1)))
 157
 158 ;;;###autoload
 159 (define-globalized-minor-mode global-diff-hl-mode diff-hl-mode
 160   turn-on-diff-hl-mode)
 161
 162 (provide 'diff-hl)