[elpa] master f300548 33/42: Merge pull request #50 from PythonNut/master

[Dmitry Gutov]

branch: master
commit f30054876d5fb5c7c320b60b32f8557ee79c4cde
Merge: 028b2bf 418dbc7
Author: Dmitry Gutov <address@hidden>
Commit: Dmitry Gutov <address@hidden>

    Merge pull request #50 from PythonNut/master
    
    [WIP] Allow diffing on-the-fly
---
 README.md          |    6 +--
 diff-hl-flydiff.el |  169 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 diff-hl.el         |   33 ++++++----
 3 files changed, 189 insertions(+), 19 deletions(-)

diff --git a/README.md b/README.md
index a0d5168..20274bb 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@ The package also contains auxiliary modes:
 * `diff-hl-margin-mode` changes the highlighting function to
   use the margin instead of the fringe.
 * `diff-hl-amend-mode` shifts the reference revision back by one.
+* `diff-hl-flydiff-mode` enables diffing unsaved changes
 
 Check out the Commentary section in each respective file for the usage
 instructions.
@@ -46,11 +47,6 @@ Emacs 24+. On OS X, Emacs 24.3 or higher is recommended.
 Notes
 =====
 
-* Since it uses the corresponding VC diff command, it's only accurate when the
-  buffer is in saved state. Highlighting changes "on the fly" might be better,
-  maybe we can do something similar to `highlight-markup-buffers` with a hidden
-  buffer containing the unmodified copy.
-
 * We conflict with other modes when they put indicators on the fringe,
   such as [Flycheck](https://github.com/flycheck/flycheck). This is
   rarely a significant problem, since if you're using such a mode,
diff --git a/diff-hl-flydiff.el b/diff-hl-flydiff.el
new file mode 100644
index 0000000..b5f6b4c
--- /dev/null
+++ b/diff-hl-flydiff.el
@@ -0,0 +1,169 @@
+;; Copyright (C) 2015 Free Software Foundation, Inc.
+
+;; Author:   Jonathan Hayase <address@hidden>
+;; URL:      https://github.com/dgutov/diff-hl
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This mode enables diffing on-the-fly (i.e. without saving the buffer first)
+;; Toggle in all buffers with M-x diff-hl-flydiff-mode
+
+;;; Code:
+
+(require 'diff-hl)
+(require 'nadvice)
+
+(defvar diff-hl-flydiff-modified-tick 0)
+(defvar diff-hl-flydiff-timer)
+(make-variable-buffer-local 'diff-hl-flydiff-modified-tick)
+
+;; Polyfill concrete revisions for vc-git-working-revision in Emacs 24.4, 24.5
+(when (version<= emacs-version "25.0")
+  (with-eval-after-load 'vc-git
+    (defun vc-git--symbolic-ref (file)
+      (or
+        (vc-file-getprop file 'vc-git-symbolic-ref)
+        (let* (process-file-side-effects
+                (str (vc-git--run-command-string nil "symbolic-ref" "HEAD")))
+          (vc-file-setprop file 'vc-git-symbolic-ref
+            (if str
+              (if (string-match "^\\(refs/heads/\\)?\\(.+\\)$" str)
+                (match-string 2 str)
+                str))))))
+
+    (defun diff-hl-flydiff/vc-git-working-revision (_file)
+      "Git-specific version of `vc-working-revision'."
+      (let (process-file-side-effects)
+        (vc-git--rev-parse "HEAD")))
+
+    (defun diff-hl-flydiff/vc-git-mode-line-string (file)
+      "Return a string for `vc-mode-line' to put in the mode line for FILE."
+      (let* ((rev (vc-working-revision file))
+              (disp-rev (or (vc-git--symbolic-ref file)
+                          (substring rev 0 7)))
+              (def-ml (vc-default-mode-line-string 'Git file))
+              (help-echo (get-text-property 0 'help-echo def-ml)))
+        (propertize (replace-regexp-in-string (concat rev "\\'") disp-rev 
def-ml t t)
+          'help-echo (concat help-echo "\nCurrent revision: " rev))))
+
+    (advice-add 'vc-git-working-revision :override
+      #'diff-hl-flydiff/vc-git-working-revision)
+    (advice-add 'vc-git-mode-line-string :override
+      #'diff-hl-flydiff/vc-git-mode-line-string)))
+
+(defun diff-hl-flydiff/working-revision (file)
+  "Like vc-working-revision, but always up-to-date"
+  (vc-file-setprop file 'vc-working-revision
+    (vc-call-backend (vc-backend file) 'working-revision file)))
+
+(defun diff-hl-flydiff-make-temp-file-name (file rev &optional manual)
+  "Return a backup file name for REV or the current version of FILE.
+If MANUAL is non-nil it means that a name for backups created by
+the user should be returned."
+  (let* ((auto-save-file-name-transforms
+           `((".*" ,temporary-file-directory t))))
+    (expand-file-name
+      (concat (make-auto-save-file-name)
+        ".~" (subst-char-in-string
+               ?/ ?_ rev)
+        (unless manual ".") "~")
+      temporary-file-directory)))
+
+(defun diff-hl-flydiff-create-revision (file revision)
+  "Read REVISION of FILE into a buffer and return the buffer."
+  (let ((automatic-backup (diff-hl-flydiff-make-temp-file-name file revision))
+         (filebuf (get-file-buffer file))
+         (filename (diff-hl-flydiff-make-temp-file-name file revision 
'manual)))
+    (unless (file-exists-p filename)
+      (if (file-exists-p automatic-backup)
+        (rename-file automatic-backup filename nil)
+        (with-current-buffer filebuf
+          (let ((failed t)
+                 (coding-system-for-read 'no-conversion)
+                 (coding-system-for-write 'no-conversion))
+            (unwind-protect
+              (with-temp-file filename
+                (let ((outbuf (current-buffer)))
+                  ;; Change buffer to get local value of
+                  ;; vc-checkout-switches.
+                  (with-current-buffer filebuf
+                    (vc-call find-revision file revision outbuf))))
+              (setq failed nil)
+              (when (and failed (file-exists-p filename))
+                (delete-file filename)))))))
+    filename))
+
+(defun diff-hl-flydiff-buffer-with-head (file &optional backend)
+  "View the differences between BUFFER and its associated file.
+This requires the external program `diff' to be in your `exec-path'."
+  (interactive)
+  (vc-ensure-vc-buffer)
+  (with-current-buffer (get-buffer (current-buffer))
+    (let* ((temporary-file-directory
+             (if (file-directory-p "/dev/shm/")
+               "/dev/shm/"
+               temporary-file-directory))
+            (rev (diff-hl-flydiff-create-revision file
+                   (diff-hl-flydiff/working-revision file))))
+      (diff-no-select rev (current-buffer) "-U 0" 'noasync
+        (get-buffer-create " *diff-hl-diff*")))))
+
+(defun diff-hl-flydiff/update (old-fun &optional auto)
+  (unless (and auto
+            (or
+              (= diff-hl-flydiff-modified-tick (buffer-modified-tick))
+              (file-remote-p default-directory)
+              (not (buffer-modified-p))))
+    (funcall old-fun)))
+
+(defun diff-hl-flydiff/modified-p (state)
+  (buffer-modified-p))
+
+(defun diff-hl-flydiff/update-modified-tick (&rest args)
+  (setq diff-hl-flydiff-modified-tick (buffer-modified-tick)))
+
+;;;###autoload
+(define-minor-mode diff-hl-flydiff-mode
+  "Highlight diffs on-the-fly"
+  :lighter ""
+  :global t
+  (if diff-hl-flydiff-mode
+    (progn
+      (advice-add 'diff-hl-update :around #'diff-hl-flydiff/update)
+      (advice-add 'diff-hl-overlay-modified :override #'ignore)
+
+      (advice-add 'diff-hl-modified-p :before-until
+        #'diff-hl-flydiff/modified-p)
+      (advice-add 'diff-hl-changes-buffer :override
+        #'diff-hl-flydiff-buffer-with-head)
+      (advice-add 'diff-hl-change :after
+        #'diff-hl-flydiff/update-modified-tick)
+
+      (setq diff-hl-flydiff-timer
+        (run-with-idle-timer 0.3 t #'diff-hl-update t)))
+
+    (advice-remove 'diff-hl-update #'diff-hl-flydiff/update)
+    (advice-remove 'diff-hl-overlay-modified #'ignore)
+
+    (advice-remove 'diff-hl-modified-p #'diff-hl-flydiff/modified-p)
+    (advice-remove 'diff-hl-changes-buffer #'diff-hl-flydiff-buffer-with-head)
+    (advice-remove 'diff-hl-change #'diff-hl-flydiff/update-modified-tick)
+
+    (cancel-timer diff-hl-flydiff-timer)))
+
+(provide 'diff-hl-flydiff)
diff --git a/diff-hl.el b/diff-hl.el
index 18b92c7..50714b2 100644
--- a/diff-hl.el
+++ b/diff-hl.el
@@ -217,26 +217,31 @@
              '((vc-disable-async-diff t))))
      ,body))
 
+(defun diff-hl-modified-p (state)
+  (or (eq state 'edited)
+    (and (eq state 'up-to-date)
+      ;; VC state is stale in after-revert-hook.
+      (or revert-buffer-in-progress-p
+        ;; Diffing against an older revision.
+        diff-hl-reference-revision))))
+
+(defun diff-hl-changes-buffer (file backend)
+  (let ((buf-name " *diff-hl* "))
+    (diff-hl-with-diff-switches
+      (vc-call-backend backend 'diff (list file)
+        diff-hl-reference-revision nil
+        buf-name))
+    buf-name))
+
 (defun diff-hl-changes ()
   (let* ((file buffer-file-name)
          (backend (vc-backend file)))
     (when backend
       (let ((state (vc-state file backend)))
         (cond
-         ((or (eq state 'edited)
-              (and (eq state 'up-to-date)
-                   ;; VC state is stale in after-revert-hook.
-                   (or revert-buffer-in-progress-p
-                       ;; Diffing against an older revision.
-                       diff-hl-reference-revision)))
-          (let* ((buf-name " *diff-hl* ")
-                 diff-auto-refine-mode
-                 res)
-            (diff-hl-with-diff-switches
-             (vc-call-backend backend 'diff (list file)
-                              diff-hl-reference-revision nil
-                              buf-name))
-            (with-current-buffer buf-name
+         ((diff-hl-modified-p state)
+          (let* (diff-auto-refine-mode res)
+            (with-current-buffer (diff-hl-changes-buffer file backend)
               (goto-char (point-min))
               (unless (eobp)
                 (ignore-errors