;;; 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-mode
- "Toggle Highlight Changes mode.
+ "Toggle highlighting changes in this buffer (Highlight Changes mode).
+With a prefix argument ARG, enable Highlight Changes mode if ARG
+is positive, and disable it otherwise. If called from Lisp,
+enable the mode if ARG is omitted or nil.
-With ARG, turn Highlight Changes mode on if and only if arg is positive.
-
-In Highlight Changes mode changes are recorded with a text property.
-Normally they are displayed in a distinctive face, but command
-\\[highlight-changes-visible-mode] can be used to toggles this
-on and off.
+When Highlight Changes is enabled, changes are marked with a text
+property. Normally they are displayed in a distinctive face, but
+command \\[highlight-changes-visible-mode] can be used to toggles
+this on and off.
Other functions for buffers in this mode include:
\\[highlight-changes-next-change] - move point to beginning of next change
;;;###autoload
(define-minor-mode highlight-changes-visible-mode
- "Toggle visiblility of changes when buffer is in 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.
-This mode only has an effect when Highlight Changes mode is on.
-It allows toggling between whether or not the changed text is displayed
+Highlight Changes Visible mode only has an effect when Highlight
+Changes mode is on. When enabled, the changed text is displayed
in a distinctive face.
The default value can be customized with variable
-`highlight-changes-visibility-initial-state'
+`highlight-changes-visibility-initial-state'.
This command does not itself set highlight-changes mode."
(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."
;; (defun hilit-chg-debug-show (&optional beg end)
;; (interactive)
;; (message "--- hilit-chg-debug-show ---")
-;; (hilit-chg-map-changes '(lambda (prop start end)
-;; (message "%d-%d: %s" start end prop)
-;; )
+;; (hilit-chg-map-changes (lambda (prop start end)
+;; (message "%d-%d: %s" start end prop))
;; beg end
;; ))
;;
HCoop / bpt / emacs.git / blobdiff