Added softext.el

diff --git a/text/softtext.el b/text/softtext.el
new file mode 100644 (file)
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--- /dev/null
+++ b/text/softtext.el
@@ -0,0 +1,131 @@
+;;; softtext.el --- Load/Save translator for soft text files
+;;
+;; $Id$
+;;
+;; Copyright (C) 1999 Stefan Bund
+
+;; softtext.el 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 2, or (at your
+;; option) any later version.
+
+;; softtext.el 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.
+
+;;; Commentary:
+
+;; Externally soft newlines are represented as ordinary newlines with
+;; a preceding space. For this to work reliably, spaces before
+;; newlines are removed prior to writing a buffer out to it's external
+;; representation and re-inserted as annotations in the buffer
+;; encoding function.
+
+;;; Change-Log:
+
+;; $Log$
+;;
+
+;;; Variables:
+
+;;; Code:
+
+(defun softtext-convert-external-to-internal (start end)
+  (let ((mod (buffer-modified-p)))
+    (save-excursion
+      (goto-char start)
+      (if (save-excursion (search-forward "\r\n" nil t))
+          ;;; Old version compatibility
+          (while (search-forward "\r\n" end t)
+            (replace-match "\n")
+            (set-hard-newline-properties (1- (point)) (point)))
+        (while (search-forward "\n" end t)
+         (if (and (> (match-beginning 0) start)
+                  (eq (string-to-char (buffer-substring-no-properties (1- (match-beginning 0))
+                                                                          (match-beginning 0)))
+                      ? ))
+             (save-excursion
+               (goto-char (1- (match-beginning 0)))
+               (delete-char 1))
+           (set-hard-newline-properties (match-beginning 0)
+                                        (match-end 0))))))
+    (set-buffer-modified-p mod)))
+
+(defun softtext-convert-internal-to-external (start end &optional buffer)
+  (let ((mod (buffer-modified-p))
+       annotations)
+    (save-excursion
+      (if buffer (set-buffer buffer))
+      (save-excursion
+        (goto-char start)
+        (while (search-forward "\n" end t)
+          (if (not (get-text-property (1- (point)) 'hard))
+             (if buffer
+                 (setq annotations (cons (cons (- (point) start) " ")
+                                         annotations))
+               (forward-char -1)
+               (insert " ")
+               (forward-char 1))))))
+    (if (not buffer) (set-buffer-modified-p mod))
+    (nreverse annotations)))
+
+(defun softtext-cleanup-buffer ()
+  (save-excursion
+    (goto-char (point-min))
+    (while (re-search-forward " *\n" nil t)
+      (let ((blanks (- (match-end 0) (match-beginning 0) 1)))
+       (if (> blanks 0)
+           (progn
+             (goto-char (match-beginning 0))
+             (delete-char blanks)
+             (forward-char 1)))))))
+
+(defun softtext-hard-newlines-region (start end)
+  (interactive "r")
+  (save-excursion
+    (goto-char start)
+    (while (search-forward "\n" end t)
+      (set-hard-newline-properties (1- (point)) (point)))))
+
+(let ((x (assq 'softtext format-alist)))
+  (if x (setq format-alist (delq x format-alist))))
+
+(let ((elt (assq 'softtext format-alist)))
+  (if elt (setq format-alist (delq elt format-alist)))
+  (setq format-alist
+       (cons '(softtext "Text with hard/soft newlines" nil
+                        softtext-convert-external-to-internal
+                        softtext-convert-internal-to-external
+                        nil nil)
+             format-alist)))
+
+(define-minor-mode softwrap-mode
+  "Toggle SoftWrap minor mode.
+With no argument, this command toggles SoftWrap mode. A Non-null
+prefix argument enables the mode, a null prefix argument disables it.
+
+In SoftWrap mode, emacs differentiates between hard and soft
+newlines. On writing out the buffer to its file, soft newlines a
+reconverted to ordinary newlines preceded by a single space. Any other
+whitspace preceding a newline is removed."
+  nil
+  " SoftWrap"
+  nil
+  (if softwrap-mode
+      (when (not (memq 'softtext buffer-file-format))
+       (softtext-convert-external-to-internal (point-min) (point-max))
+       (setq buffer-file-format (append buffer-file-format (list 'softtext)))
+       (setq use-hard-newlines t)
+       (add-hook 'write-contents-hooks 'softtext-cleanup-buffer))
+    (when (memq 'softtext buffer-file-format)
+      (remove-hook 'write-contents-hooks 'softtext-cleanup-buffer)
+      (setq use-hard-newlines nil)
+      (setq buffer-file-format (delq 'softtext buffer-file-format))
+      (softtext-convert-internal-to-external (point-min) (point-max)))))
+
+(define-derived-mode softtext-mode indented-text-mode "Text"
+  "SoftText Mode is indented-text-mode with SoftWrap minor mode enabled"
+  (softwrap-mode 1))
+
+(provide 'softtext)