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

   1 ;; Copyright (C) 2015, 2016 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 (defgroup diff-hl-flydiff nil
  34   "Highlight changes on the fly"
  35   :group 'diff-hl)
  36
  37 (defcustom diff-hl-flydiff-delay 0.3
  38   "The idle delay in seconds before highlighting is updated."
  39   :type 'number)
  40
  41 (defvar diff-hl-flydiff-modified-tick 0)
  42 (defvar diff-hl-flydiff-timer nil)
  43 (make-variable-buffer-local 'diff-hl-flydiff-modified-tick)
  44
  45 (defun diff-hl-flydiff/vc-git--symbolic-ref (file)
  46   (or
  47    (vc-file-getprop file 'vc-git-symbolic-ref)
  48    (let* (process-file-side-effects
  49           (str (vc-git--run-command-string nil "symbolic-ref" "HEAD")))
  50      (vc-file-setprop file 'vc-git-symbolic-ref
  51                       (if str
  52                           (if (string-match "^\\(refs/heads/\\)?\\(.+\\)$" str)
  53                               (match-string 2 str)
  54                             str))))))
  55
  56 (defun diff-hl-flydiff/vc-git-working-revision (_file)
  57   "Git-specific version of `vc-working-revision'."
  58   (let (process-file-side-effects)
  59     (vc-git--rev-parse "HEAD")))
  60
  61 (defun diff-hl-flydiff/vc-git-mode-line-string (file)
  62   "Return a string for `vc-mode-line' to put in the mode line for FILE."
  63   (let* ((rev (vc-working-revision file))
  64          (disp-rev (or (diff-hl-flydiff/vc-git--symbolic-ref file)
  65                        (substring rev 0 7)))
  66          (def-ml (vc-default-mode-line-string 'Git file))
  67          (help-echo (get-text-property 0 'help-echo def-ml))
  68          (face   (get-text-property 0 'face def-ml)))
  69     (propertize (replace-regexp-in-string (concat rev "\\'") disp-rev def-ml t t)
  70                 'face face
  71                 'help-echo (concat help-echo "\nCurrent revision: " rev))))
  72
  73 ;; Polyfill concrete revisions for vc-git-working-revision in Emacs 24.4, 24.5
  74 (when (version<= emacs-version "25.0")
  75   (with-eval-after-load 'vc-git
  76     (advice-add 'vc-git-working-revision :override
  77                 #'diff-hl-flydiff/vc-git-working-revision)
  78     (advice-add 'vc-git-mode-line-string :override
  79                 #'diff-hl-flydiff/vc-git-mode-line-string)))
  80
  81 (defun diff-hl-flydiff/working-revision (file)
  82   "Like vc-working-revision, but always up-to-date"
  83   (vc-file-setprop file 'vc-working-revision
  84                    (vc-call-backend (vc-backend file) 'working-revision file)))
  85
  86 (defun diff-hl-flydiff-make-temp-file-name (file rev &optional manual)
  87   "Return a backup file name for REV or the current version of FILE.
  88 If MANUAL is non-nil it means that a name for backups created by
  89 the user should be returned."
  90   (let* ((auto-save-file-name-transforms
  91           `((".*" ,temporary-file-directory t))))
  92     (expand-file-name
  93      (concat (make-auto-save-file-name)
  94              ".~" (subst-char-in-string
  95                    ?/ ?_ rev)
  96              (unless manual ".") "~")
  97      temporary-file-directory)))
  98
  99 (defun diff-hl-flydiff-create-revision (file revision)
 100   "Read REVISION of FILE into a buffer and return the buffer."
 101   (let ((automatic-backup (diff-hl-flydiff-make-temp-file-name file revision))
 102         (filebuf (get-file-buffer file))
 103         (filename (diff-hl-flydiff-make-temp-file-name file revision 'manual)))
 104     (unless (file-exists-p filename)
 105       (if (file-exists-p automatic-backup)
 106           (rename-file automatic-backup filename nil)
 107         (with-current-buffer filebuf
 108           (let ((coding-system-for-read 'no-conversion)
 109                 (coding-system-for-write 'no-conversion))
 110             (condition-case nil
 111                 (with-temp-file filename
 112                   (let ((outbuf (current-buffer)))
 113                     ;; Change buffer to get local value of
 114                     ;; vc-checkout-switches.
 115                     (with-current-buffer filebuf
 116                       (vc-call find-revision file revision outbuf))))
 117               (error
 118                (when (file-exists-p filename)
 119                  (delete-file filename))))))))
 120     filename))
 121
 122 (defun diff-hl-flydiff-buffer-with-head (file &optional backend)
 123   "View the differences between BUFFER and its associated file.
 124 This requires the external program `diff' to be in your `exec-path'."
 125   (interactive)
 126   (vc-ensure-vc-buffer)
 127   (setq diff-hl-flydiff-modified-tick (buffer-modified-tick))
 128   (save-current-buffer
 129     (let* ((temporary-file-directory
 130             (if (file-directory-p "/dev/shm/")
 131                 "/dev/shm/"
 132               temporary-file-directory))
 133            (rev (diff-hl-flydiff-create-revision
 134                  file
 135                  (diff-hl-flydiff/working-revision file))))
 136       (diff-no-select rev (current-buffer) "-U 0 --strip-trailing-cr" 'noasync
 137                       (get-buffer-create " *diff-hl-diff*")))))
 138
 139 (defun diff-hl-flydiff-update ()
 140   (unless (or
 141            (not diff-hl-mode)
 142            (= diff-hl-flydiff-modified-tick (buffer-modified-tick))
 143            (file-remote-p default-directory))
 144     (diff-hl-update)))
 145
 146 (defun diff-hl-flydiff/modified-p (state)
 147   (buffer-modified-p))
 148
 149 ;;;###autoload
 150 (define-minor-mode diff-hl-flydiff-mode
 151   "Highlight diffs on-the-fly"
 152   :lighter ""
 153   :global t
 154   (if diff-hl-flydiff-mode
 155       (progn
 156         (advice-add 'diff-hl-overlay-modified :override #'ignore)
 157
 158         (advice-add 'diff-hl-modified-p :before-until
 159                     #'diff-hl-flydiff/modified-p)
 160         (advice-add 'diff-hl-changes-buffer :override
 161                     #'diff-hl-flydiff-buffer-with-head)
 162         (setq diff-hl-flydiff-timer
 163               (run-with-idle-timer diff-hl-flydiff-delay t #'diff-hl-flydiff-update)))
 164
 165     (advice-remove 'diff-hl-overlay-modified #'ignore)
 166
 167     (advice-remove 'diff-hl-modified-p #'diff-hl-flydiff/modified-p)
 168     (advice-remove 'diff-hl-changes-buffer #'diff-hl-flydiff-buffer-with-head)
 169
 170     (and diff-hl-flydiff-timer
 171          (cancel-timer diff-hl-flydiff-timer))))
 172
 173 (provide 'diff-hl-flydiff)