;;; hilit-chg.el --- minor mode displaying buffer changes with special face
-;; Copyright (C) 1998, 2000-2011 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 2000-2013 Free Software Foundation, Inc.
;; Author: Richard Sharman <rsharman@pobox.com>
;; Keywords: faces
;;;###autoload
(define-minor-mode highlight-changes-visible-mode
- "Toggle visiblility of highlighting due to Highlight Changes mode.
+ "Toggle visibility of highlighting due to Highlight Changes mode.
With a prefix argument ARG, enable Highlight Changes Visible mode
if ARG is positive, and disable it otherwise. If called from
Lisp, enable the mode if ARG is omitted or nil.
(defun hilit-chg-make-ov (prop start end)
(or prop
(error "hilit-chg-make-ov: prop is nil"))
- ;; For the region create overlays with a distincive face
+ ;; For the region create overlays with a distinctive face
;; and the text property 'hilit-chg.
(let ((ov (make-overlay start end))
(face (if (eq prop 'hilit-chg-delete)
highlight-changes-visible-mode)
(hilit-chg-fixup beg end))
(highlight-save-buffer-state
- (if (and (= beg end) (> leng-before 0))
- ;; deletion
- (progn
- ;; The eolp and bolp tests are a kludge! But they prevent
- ;; rather nasty looking displays when deleting text at the end
- ;; of line, such as normal corrections as one is typing and
- ;; immediately makes a correction, and when deleting first
- ;; character of a line.
- ;; (if (= leng-before 1)
- ;; (if (eolp)
- ;; (setq beg-decr 0 end-incr 0)
- ;; (if (bolp)
- ;; (setq beg-decr 0))))
- ;; (setq beg (max (- beg beg-decr) (point-min)))
- (setq end (min (+ end end-incr) (point-max)))
- (setq type 'hilit-chg-delete))
- ;; Not a deletion.
- ;; Most of the time the following is not necessary, but
- ;; if the current text was marked as a deletion then
- ;; the old overlay is still in effect, so if we add some
- ;; text then remove the deletion marking, but set it to
- ;; changed otherwise its highlighting disappears.
- (if (eq (get-text-property end 'hilit-chg) 'hilit-chg-delete)
- (progn
- (put-text-property end (+ end 1) 'hilit-chg 'hilit-chg)
- (if highlight-changes-visible-mode
- (hilit-chg-fixup beg (+ end 1))))))
- (unless no-property-change
- (put-text-property beg end 'hilit-chg type))
- (if (or highlight-changes-visible-mode no-property-change)
- (hilit-chg-make-ov type beg end)))))))
+ (if (and (= beg end) (> leng-before 0))
+ ;; deletion
+ (progn
+ ;; The eolp and bolp tests are a kludge! But they prevent
+ ;; rather nasty looking displays when deleting text at the end
+ ;; of line, such as normal corrections as one is typing and
+ ;; immediately makes a correction, and when deleting first
+ ;; character of a line.
+ ;; (if (= leng-before 1)
+ ;; (if (eolp)
+ ;; (setq beg-decr 0 end-incr 0)
+ ;; (if (bolp)
+ ;; (setq beg-decr 0))))
+ ;; (setq beg (max (- beg beg-decr) (point-min)))
+ (setq end (min (+ end end-incr) (point-max)))
+ (setq type 'hilit-chg-delete))
+ ;; Not a deletion.
+ ;; Most of the time the following is not necessary, but
+ ;; if the current text was marked as a deletion then
+ ;; the old overlay is still in effect. So if the user adds some
+ ;; text where she earlier deleted text, we have to remove the
+ ;; deletion marking, and replace it explicitly with a `changed'
+ ;; marking, otherwise its highlighting would disappear.
+ (if (eq (get-text-property end 'hilit-chg) 'hilit-chg-delete)
+ (save-restriction
+ (widen)
+ (put-text-property end (+ end 1) 'hilit-chg 'hilit-chg)
+ (if highlight-changes-visible-mode
+ (hilit-chg-fixup beg (+ end 1))))))
+ (unless no-property-change
+ (put-text-property beg end 'hilit-chg type))
+ (if (or highlight-changes-visible-mode no-property-change)
+ (hilit-chg-make-ov type beg end)))))))
(defun hilit-chg-update ()
"Update a buffer's highlight changes when visibility changed."