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 'diff)
  30 (unless (require 'nadvice nil t)
  31   (error "`diff-hl-flydiff-mode' requires Emacs 24.4 or newer"))
  32
  33 (defvar diff-hl-flydiff-modified-tick 0)
  34 (defvar diff-hl-flydiff-timer)
  35 (make-variable-buffer-local 'diff-hl-flydiff-modified-tick)
  36
  37 (defun diff-hl-flydiff/vc-git--symbolic-ref (file)
  38   (or
  39    (vc-file-getprop file 'vc-git-symbolic-ref)
  40    (let* (process-file-side-effects
  41           (str (vc-git--run-command-string nil "symbolic-ref" "HEAD")))
  42      (vc-file-setprop file 'vc-git-symbolic-ref
  43                       (if str
  44                           (if (string-match "^\\(refs/heads/\\)?\\(.+\\)$" str)
  45                               (match-string 2 str)
  46                             str))))))
  47
  48 (defun diff-hl-flydiff/vc-git-working-revision (_file)
  49   "Git-specific version of `vc-working-revision'."
  50   (let (process-file-side-effects)
  51     (vc-git--rev-parse "HEAD")))
  52
  53 (defun diff-hl-flydiff/vc-git-mode-line-string (file)
  54   "Return a string for `vc-mode-line' to put in the mode line for FILE."
  55   (let* ((rev (vc-working-revision file))
  56          (disp-rev (or (diff-hl-flydiff/vc-git--symbolic-ref file)
  57                        (substring rev 0 7)))
  58          (def-ml (vc-default-mode-line-string 'Git file))
  59          (help-echo (get-text-property 0 'help-echo def-ml))
  60          (face   (get-text-property 0 'face def-ml)))
  61     (propertize (replace-regexp-in-string (concat rev "\\'") disp-rev def-ml t t)
  62                 'face face
  63                 'help-echo (concat help-echo "\nCurrent revision: " rev))))
  64
  65 ;; Polyfill concrete revisions for vc-git-working-revision in Emacs 24.4, 24.5
  66 (when (version<= emacs-version "25.0")
  67   (with-eval-after-load 'vc-git
  68     (advice-add 'vc-git-working-revision :override
  69                 #'diff-hl-flydiff/vc-git-working-revision)
  70     (advice-add 'vc-git-mode-line-string :override
  71                 #'diff-hl-flydiff/vc-git-mode-line-string)))
  72
  73 (defun diff-hl-flydiff/working-revision (file)
  74   "Like vc-working-revision, but always up-to-date"
  75   (vc-file-setprop file 'vc-working-revision
  76                    (vc-call-backend (vc-backend file) 'working-revision file)))
  77
  78 (defun diff-hl-flydiff-make-temp-file-name (file rev &optional manual)
  79   "Return a backup file name for REV or the current version of FILE.
  80 If MANUAL is non-nil it means that a name for backups created by
  81 the user should be returned."
  82   (let* ((auto-save-file-name-transforms
  83           `((".*" ,temporary-file-directory t))))
  84     (expand-file-name
  85      (concat (make-auto-save-file-name)
  86              ".~" (subst-char-in-string
  87                    ?/ ?_ rev)
  88              (unless manual ".") "~")
  89      temporary-file-directory)))
  90
  91 (defun diff-hl-flydiff-create-revision (file revision)
  92   "Read REVISION of FILE into a buffer and return the buffer."
  93   (let ((automatic-backup (diff-hl-flydiff-make-temp-file-name file revision))
  94         (filebuf (get-file-buffer file))
  95         (filename (diff-hl-flydiff-make-temp-file-name file revision 'manual)))
  96     (unless (file-exists-p filename)
  97       (if (file-exists-p automatic-backup)
  98           (rename-file automatic-backup filename nil)
  99         (with-current-buffer filebuf
 100           (let ((failed t)
 101                 (coding-system-for-read 'no-conversion)
 102                 (coding-system-for-write 'no-conversion))
 103             (unwind-protect
 104                 (with-temp-file filename
 105                   (let ((outbuf (current-buffer)))
 106                     ;; Change buffer to get local value of
 107                     ;; vc-checkout-switches.
 108                     (with-current-buffer filebuf
 109                       (vc-call find-revision file revision outbuf))))
 110               (setq failed nil)
 111               (when (and failed (file-exists-p filename))
 112                 (delete-file filename)))))))
 113     filename))
 114
 115 (defun diff-hl-flydiff-buffer-with-head (file &optional backend)
 116   "View the differences between BUFFER and its associated file.
 117 This requires the external program `diff' to be in your `exec-path'."
 118   (interactive)
 119   (vc-ensure-vc-buffer)
 120   (with-current-buffer (get-buffer (current-buffer))
 121     (let* ((temporary-file-directory
 122             (if (file-directory-p "/dev/shm/")
 123                 "/dev/shm/"
 124               temporary-file-directory))
 125            (rev (diff-hl-flydiff-create-revision
 126                  file
 127                  (diff-hl-flydiff/working-revision file))))
 128       (diff-no-select rev (current-buffer) "-U 0 --strip-trailing-cr" 'noasync
 129                       (get-buffer-create " *diff-hl-diff*")))))
 130
 131 (defun diff-hl-flydiff/update (old-fun &optional auto)
 132   (unless (and auto
 133                (or
 134                 (= diff-hl-flydiff-modified-tick (buffer-modified-tick))
 135                 (file-remote-p default-directory)
 136                 (not (buffer-modified-p))))
 137     (funcall old-fun)))
 138
 139 (defun diff-hl-flydiff/modified-p (state)
 140   (buffer-modified-p))
 141
 142 (defun diff-hl-flydiff/update-modified-tick (&rest args)
 143   (setq diff-hl-flydiff-modified-tick (buffer-modified-tick)))
 144
 145 ;;;###autoload
 146 (define-minor-mode diff-hl-flydiff-mode
 147   "Highlight diffs on-the-fly"
 148   :lighter ""
 149   :global t
 150   (if diff-hl-flydiff-mode
 151       (progn
 152         (advice-add 'diff-hl-update :around #'diff-hl-flydiff/update)
 153         (advice-add 'diff-hl-overlay-modified :override #'ignore)
 154
 155         (advice-add 'diff-hl-modified-p :before-until
 156                     #'diff-hl-flydiff/modified-p)
 157         (advice-add 'diff-hl-changes-buffer :override
 158                     #'diff-hl-flydiff-buffer-with-head)
 159         (advice-add 'diff-hl-change :after
 160                     #'diff-hl-flydiff/update-modified-tick)
 161
 162         (setq diff-hl-flydiff-timer
 163               (run-with-idle-timer 0.3 t #'diff-hl-update t)))
 164
 165     (advice-remove 'diff-hl-update #'diff-hl-flydiff/update)
 166     (advice-remove 'diff-hl-overlay-modified #'ignore)
 167
 168     (advice-remove 'diff-hl-modified-p #'diff-hl-flydiff/modified-p)
 169     (advice-remove 'diff-hl-changes-buffer #'diff-hl-flydiff-buffer-with-head)
 170     (advice-remove 'diff-hl-change #'diff-hl-flydiff/update-modified-tick)
 171
 172     (cancel-timer diff-hl-flydiff-timer)))
 173
 174 (provide 'diff-hl-flydiff)