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

   1 ;; Copyright (C) 2015 Free Software Foundation, Inc.
   2
   3 ;; Author:   Jonathan Hayase <PythonNut@gmail.com>
   4 ;; URL:      https://github.com/dgutov/diff-hl
   5
   6 ;; This file is part of GNU Emacs.
   7
   8 ;; GNU Emacs 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 ;; GNU Emacs 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 ;;; Commentary:
  22
  23 ;; This mode enables diffing on-the-fly (i.e. without saving the buffer first)
  24 ;; Toggle in all buffers with M-x diff-hl-flydiff-mode
  25
  26 ;;; Code:
  27
  28 (require 'diff-hl)
  29 (require 'nadvice)
  30
  31 (defvar diff-hl-flydiff-modified-tick 0)
  32 (defvar diff-hl-flydiff-timer)
  33 (make-variable-buffer-local 'diff-hl-flydiff-modified-tick)
  34
  35 ;; Polyfill concrete revisions for vc-git-working-revision in Emacs 24.4, 24.5
  36 (when (version<= emacs-version "25.0")
  37   (with-eval-after-load 'vc-git
  38     (defun vc-git--symbolic-ref (file)
  39       (or
  40         (vc-file-getprop file 'vc-git-symbolic-ref)
  41         (let* (process-file-side-effects
  42                 (str (vc-git--run-command-string nil "symbolic-ref" "HEAD")))
  43           (vc-file-setprop file 'vc-git-symbolic-ref
  44             (if str
  45               (if (string-match "^\\(refs/heads/\\)?\\(.+\\)$" str)
  46                 (match-string 2 str)
  47                 str))))))
  48
  49     (defun diff-hl-flydiff/vc-git-working-revision (_file)
  50       "Git-specific version of `vc-working-revision'."
  51       (let (process-file-side-effects)
  52         (vc-git--rev-parse "HEAD")))
  53
  54     (defun diff-hl-flydiff/vc-git-mode-line-string (file)
  55       "Return a string for `vc-mode-line' to put in the mode line for FILE."
  56       (let* ((rev (vc-working-revision file))
  57               (disp-rev (or (vc-git--symbolic-ref file)
  58                           (substring rev 0 7)))
  59               (def-ml (vc-default-mode-line-string 'Git file))
  60               (help-echo (get-text-property 0 'help-echo def-ml)))
  61         (propertize (replace-regexp-in-string (concat rev "\\'") disp-rev def-ml t t)
  62           'help-echo (concat help-echo "\nCurrent revision: " rev))))
  63
  64     (advice-add 'vc-git-working-revision :override
  65       #'diff-hl-flydiff/vc-git-working-revision)
  66     (advice-add 'vc-git-mode-line-string :override
  67       #'diff-hl-flydiff/vc-git-mode-line-string)))
  68
  69 (defun diff-hl-flydiff/working-revision (file)
  70   "Like vc-working-revision, but always up-to-date"
  71   (vc-file-setprop file 'vc-working-revision
  72     (vc-call-backend (vc-backend file) 'working-revision file)))
  73
  74 (defun diff-hl-flydiff-make-temp-file-name (file rev &optional manual)
  75   "Return a backup file name for REV or the current version of FILE.
  76 If MANUAL is non-nil it means that a name for backups created by
  77 the user should be returned."
  78   (let* ((auto-save-file-name-transforms
  79            `((".*" ,temporary-file-directory t))))
  80     (expand-file-name
  81       (concat (make-auto-save-file-name)
  82         ".~" (subst-char-in-string
  83                ?/ ?_ rev)
  84         (unless manual ".") "~")
  85       temporary-file-directory)))
  86
  87 (defun diff-hl-flydiff-create-revision (file revision)
  88   "Read REVISION of FILE into a buffer and return the buffer."
  89   (let ((automatic-backup (diff-hl-flydiff-make-temp-file-name file revision))
  90          (filebuf (get-file-buffer file))
  91          (filename (diff-hl-flydiff-make-temp-file-name file revision 'manual)))
  92     (unless (file-exists-p filename)
  93       (if (file-exists-p automatic-backup)
  94         (rename-file automatic-backup filename nil)
  95         (with-current-buffer filebuf
  96           (let ((failed t)
  97                  (coding-system-for-read 'no-conversion)
  98                  (coding-system-for-write 'no-conversion))
  99             (unwind-protect
 100               (with-temp-file filename
 101                 (let ((outbuf (current-buffer)))
 102                   ;; Change buffer to get local value of
 103                   ;; vc-checkout-switches.
 104                   (with-current-buffer filebuf
 105                     (vc-call find-revision file revision outbuf))))
 106               (setq failed nil)
 107               (when (and failed (file-exists-p filename))
 108                 (delete-file filename)))))))
 109     filename))
 110
 111 (defun diff-hl-flydiff-buffer-with-head (file &optional backend)
 112   "View the differences between BUFFER and its associated file.
 113 This requires the external program `diff' to be in your `exec-path'."
 114   (interactive)
 115   (vc-ensure-vc-buffer)
 116   (with-current-buffer (get-buffer (current-buffer))
 117     (let* ((temporary-file-directory
 118              (if (file-directory-p "/dev/shm/")
 119                "/dev/shm/"
 120                temporary-file-directory))
 121             (rev (diff-hl-flydiff-create-revision file
 122                    (diff-hl-flydiff/working-revision file))))
 123       (diff-no-select rev (current-buffer) "-U 0" 'noasync
 124         (get-buffer-create " *diff-hl-diff*")))))
 125
 126 (defun diff-hl-flydiff/update (old-fun &optional auto)
 127   (unless (and auto
 128             (or
 129               (= diff-hl-flydiff-modified-tick (buffer-modified-tick))
 130               (file-remote-p default-directory)
 131               (not (buffer-modified-p))))
 132     (funcall old-fun)))
 133
 134 (defun diff-hl-flydiff/modified-p (state)
 135   (buffer-modified-p))
 136
 137 (defun diff-hl-flydiff/update-modified-tick (&rest args)
 138   (setq diff-hl-flydiff-modified-tick (buffer-modified-tick)))
 139
 140 ;;;###autoload
 141 (define-minor-mode diff-hl-flydiff-mode
 142   "Highlight diffs on-the-fly"
 143   :lighter ""
 144   :global t
 145   (if diff-hl-flydiff-mode
 146     (progn
 147       (advice-add 'diff-hl-update :around #'diff-hl-flydiff/update)
 148       (advice-add 'diff-hl-overlay-modified :override #'ignore)
 149
 150       (advice-add 'diff-hl-modified-p :before-until
 151         #'diff-hl-flydiff/modified-p)
 152       (advice-add 'diff-hl-changes-buffer :override
 153         #'diff-hl-flydiff-buffer-with-head)
 154       (advice-add 'diff-hl-change :after
 155         #'diff-hl-flydiff/update-modified-tick)
 156
 157       (setq diff-hl-flydiff-timer
 158         (run-with-idle-timer 0.3 t #'diff-hl-update t)))
 159
 160     (advice-remove 'diff-hl-update #'diff-hl-flydiff/update)
 161     (advice-remove 'diff-hl-overlay-modified #'ignore)
 162
 163     (advice-remove 'diff-hl-modified-p #'diff-hl-flydiff/modified-p)
 164     (advice-remove 'diff-hl-changes-buffer #'diff-hl-flydiff-buffer-with-head)
 165     (advice-remove 'diff-hl-change #'diff-hl-flydiff/update-modified-tick)
 166
 167     (cancel-timer diff-hl-flydiff-timer)))
 168
 169 (provide 'diff-hl-flydiff)