[elpa] master 89be8c1 01/22: initial commit

[Stefan Monnier]

branch: master
commit 89be8c172bec0107e91373abd14ae6371560150b
Author: Mitchel Humpherys <address@hidden>
Commit: Mitchel Humpherys <address@hidden>

    initial commit
---
 README.md   |   26 +++++++++
 diffview.el |  188 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 214 insertions(+)

diff --git a/README.md b/README.md
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--- /dev/null
+++ b/README.md
@@ -0,0 +1,26 @@
+Commentary
+==========
+
+View a diff in a side-by-side format. This comes in handy for ready
+patches from mailing lists (or from whencever you might acquire
+them).
+
+Installation
+============
+
+Put this file on your load-path and do:
+
+    (require 'diffview)
+
+Use
+===
+
+The following functions are provided:
+
+* `diffview-current` : Opens the current buffer with `diffview`
+* `diffview-region` : Opens the current region with `diffview`
+
+<div style="padding-top:15px;color: #d0d0d0;">
+Markdown README file generated by
+<a 
href="https://github.com/mgalgs/make-readme-markdown";>make-readme-markdown.el</a>
+</div>
diff --git a/diffview.el b/diffview.el
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+;;; diffview.el --- View diffs in side-by-side format
+
+;; Copyright (C) 2013, Mitchel Humpherys
+
+;; Author: Mitchel Humpherys <address@hidden>
+;; Keywords: convenience
+;; Version: 0.1
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;; View a diff in a side-by-side format. This comes in handy for ready
+;; patches from mailing lists (or from whencever you might acquire
+;; them).
+;;
+;;; Installation:
+;;
+;; Put this file on your load-path and do:
+;;
+;;`   (require 'diffview)
+;;
+;;; Use:
+;;
+;; The following functions are provided:
+;;
+;; o `diffview-current` : Opens the current buffer with `diffview`
+;; o `diffview-region` : Opens the current region with `diffview`
+;;
+;;; Code
+
+
+(defun diffview/print-all-lines-to-buffer (lines buffer-name)
+  "Prints each line in `LINES' to a buffer named `BUFFER-NAME'
+  with an intervening \n between each line"
+  (let ((old-temp-buffer (get-buffer buffer-name)))
+    ;; (with-output-to-temp-buffer buffer-name
+    (when old-temp-buffer
+      (kill-buffer old-temp-buffer))
+    (with-current-buffer (get-buffer-create buffer-name)
+      (erase-buffer)
+      (dolist (line lines)
+       (insert line "\n")))))
+
+(defvar diffview/minus-bufname "*side-by-side-1*")
+(defvar diffview/plus-bufname "*side-by-side-2*")
+(defvar diffview/saved-wincfg nil)
+(defvar diffview/regexp-is-plus-line "^\\+\\([^+]\\{1\\}\\|$\\)"
+  "a + followed by one non + or the end of the line")
+(defvar diffview/regexp-is-minus-line "^-\\([^-]\\{1\\}\\|$\\)"
+  "a - followed by one non - or the end of the line")
+
+(defun diffview/view-string (input-string)
+  "Parses `INPUT-STRING' as a diff and opens the result in a
+side-by-side view"
+  (setq diffview/saved-wincfg (current-window-configuration))
+  (delete-other-windows)
+  (let (plus-lines
+       minus-lines
+       tmp-line
+       (current-state 'in-common)
+       (last-state 'in-common)
+       (current-lines-in-plus 0)
+       (current-lines-in-minus 0)
+       (total-lines 0)
+       (all-lines (split-string input-string "\n")))
+    (dolist (line all-lines)
+      (cond
+       ((string-match diffview/regexp-is-plus-line line)
+       (push line plus-lines)
+       (setq current-state 'in-plus)
+       (setq current-lines-in-plus (1+ current-lines-in-plus)))
+       ((string-match diffview/regexp-is-minus-line line)
+       (push line minus-lines)
+       (setq current-state 'in-minus)
+       (setq current-lines-in-minus (1+ current-lines-in-minus)))
+       ;; everything else must be common
+       (t
+       (push line plus-lines)
+       (push line minus-lines)
+       (setq current-state 'in-common)))
+
+      (setq total-lines (1+ total-lines))
+
+      ;; Process hunk state transitions
+      (when (not (equal current-state last-state))
+       ;; there's been a state change
+       (when (equal current-state 'in-common)
+         ;; we're transitioning out the +/- part of a hunk. We would
+         ;; like both sides to have the same number lines for this
+         ;; hunk, so we might need to fill one side or the other with
+         ;; empty lines.
+         (cond
+          ((> current-lines-in-plus current-lines-in-minus)
+           ;; need to fill minus
+           (setq tmp-line (pop minus-lines))
+           (dotimes (i (- current-lines-in-plus current-lines-in-minus))
+             (push "" minus-lines))
+           (push tmp-line minus-lines))
+          ((< current-lines-in-plus current-lines-in-minus)
+           ;; need to fill plus
+           (setq tmp-line (pop plus-lines))
+           (dotimes (i (- current-lines-in-minus current-lines-in-plus))
+             (push "" plus-lines))
+           (push tmp-line plus-lines)))
+
+         (setq current-lines-in-plus  0
+               current-lines-in-minus 0)))
+
+      (setq last-state current-state))
+
+    (diffview/print-all-lines-to-buffer (reverse minus-lines) 
diffview/minus-bufname)
+    (diffview/print-all-lines-to-buffer (reverse plus-lines) 
diffview/plus-bufname)
+
+    (switch-to-buffer diffview/minus-bufname nil t)
+    (goto-char (point-min))
+    (diffview-mode)
+
+    (split-window-right)
+    (other-window 1)
+
+    (switch-to-buffer diffview/plus-bufname nil t)
+    (goto-char (point-min))
+    (diffview-mode)
+
+    (scroll-all-mode)))
+
+(defun diffview-current ()
+  "Parses the content of the current buffer as a diff and opens
+  the result in a side-by-side view"
+  (interactive)
+  (diffview/view-string (buffer-string)))
+
+(defun diffview-region ()
+  "Parses the content of the current buffer as a diff and opens
+  the result in a side-by-side view"
+  (interactive)
+  (diffview/view-string (buffer-substring (point) (mark))))
+
+(defun diffview-message ()
+  "Parses the content of the current buffer (assumed to be a
+  message (i.e. in `Article' mode)) as a diff and opens the
+  result in a side-by-side view"
+  (interactive)
+  (let (beg end)
+    (save-excursion
+      (message-goto-body)
+      (search-forward-regexp "^---$")
+      (setq beg (1+ (point)))
+      (search-forward-regexp "^-- $")
+      (setq end (1+ (point)))
+      (diffview/view-string (buffer-substring beg end)))))
+
+
+
+;;; diffview-mode ;;;
+
+(define-derived-mode diffview-mode special-mode "Diffview"
+  "Mode for viewing diffs side-by-side"
+  (setq font-lock-defaults '(diff-font-lock-keywords t nil nil nil 
(font-lock-multiline . nil))))
+
+(defun diffview/quit ()
+  "Quit diffview and clean up diffview buffers"
+  (interactive)
+  (delete-other-windows)
+  (scroll-all-mode 0)
+  (let ((plusbuf (get-buffer diffview/plus-bufname))
+       (minusbuf (get-buffer diffview/minus-bufname)))
+    (if plusbuf (kill-buffer plusbuf))
+    (if minusbuf (kill-buffer minusbuf)))
+  (set-window-configuration diffview/saved-wincfg))
+
+(define-key diffview-mode-map (kbd "q") 'diffview/quit)
+
+(provide 'diffview)
+;;; diffview.el ends here
+;;