+;;; auto-show.el --- perform automatic horizontal scrolling as point moves
;;; This file is in the public domain.
-;;; Keywords: scroll display minor-mode
+;;; Keywords: scroll display convenience
;;; Author: Pete Ware <ware@cis.ohio-state.edu>
;;; Maintainer: FSF
;;; Commentary:
-;;; This file provides functions that
-;;; automatically scroll the window horizontally when the point moves
-;;; off the left or right side of the window.
-
-;;; Once this library is loaded, automatic horizontal scrolling
-;;; occurs whenever long lines are being truncated.
-;;; To request truncation of long lines, set the variable
-;;; Setting the variable `truncate-lines' to non-nil.
-;;; You can do this for all buffers as follows:
-;;;
-;;; (set-default 'truncate-lines t)
-
-;;; Here is how to do it for C mode only:
-;;;
-;;; (set-default 'truncate-lines nil) ; this is the original value
-;;; (defun my-c-mode-hook ()
-;;; "Run when C-mode starts up. Changes ..."
-;;; ... set various personal preferences ...
-;;; (setq truncate-lines t))
-;;; (add-hook 'c-mode-hook 'my-c-mode-hook)
-;;;
-;;;
-;;; As a finer level of control, you can still have truncated lines but
-;;; without the automatic horizontal scrolling by setting the buffer
-;;; local variable `auto-show-mode' to nil. The default value is t.
-;;; The command `auto-show-mode' toggles the value of the variable
-;;; `auto-show-mode'.
+;; This file contains dummy variables and functions only because Emacs
+;; does hscrolling automatically, now.
;;; Code:
-(defvar auto-show-mode t
- "*Non-nil enables automatic horizontal scrolling, when lines are truncated.
-The default value is t. To change the default, do this:
- (set-default 'auto-show-mode nil)
-See also command `auto-show-mode'.
-This variable has no effect when lines are not being truncated.")
-
-(make-variable-buffer-local 'auto-show-mode)
-
-(defvar auto-show-shift-amount 8
- "*Extra columns to scroll. for automatic horizontal scrolling.")
+(defgroup auto-show nil
+ "This customization group is kept for compatibilry only.
+Emacs now does hscrolling automatically. Please remove references
+to hscroll from your init file and code."
+ :group 'editing)
-(defvar auto-show-show-left-margin-threshold 50
- "*Threshold column for automatic horizontal scrolling to the right.
-If point is before this column, we try to scroll to make the left margin
-visible. Setting this to 0 disables this feature.")
-
-(defun auto-show-truncationp ()
- "True if line truncation is enabled for the selected window."
- (or truncate-lines
- (and truncate-partial-width-windows
- (< (window-width) (frame-width)))))
+;;;###autoload
+(defcustom auto-show-mode nil
+ "Obsolete."
+ :version "20.4"
+ :type 'boolean
+ :group 'auto-show)
+
+(defcustom auto-show-shift-amount 8
+ "*Obsolete."
+ :type 'integer
+ :group 'auto-show)
+
+(defcustom auto-show-show-left-margin-threshold 50
+ "*Obsolete."
+ :type 'integer
+ :group 'auto-show)
;;;###autoload
(defun auto-show-mode (arg)
- "Turn automatic horizontal scroll mode on or off.
-With arg, turn auto scrolling on if arg is positive, off otherwise."
- (interactive "P")
- (setq auto-show-mode
- (if (null arg)
- (not auto-show-mode)
- (> (prefix-numeric-value arg) 0))))
+ "This command is obsolete."
+ (interactive "P"))
(defun auto-show-make-point-visible (&optional ignore-arg)
- "Scroll horizontally to make point visible, if that is enabled.
-This function only does something if `auto-show-mode' is non-nil
-and longlines are being truncated in the selected window.
-See also the command `auto-show-toggle'."
- (interactive)
- (if (and auto-show-mode (auto-show-truncationp)
- (equal (window-buffer) (current-buffer)))
- (let* ((col (current-column)) ;column on line point is at
- (scroll (window-hscroll)) ;how far window is scrolled
- (w-width (- (window-width)
- (if (> scroll 0)
- 2 1))) ;how wide window is on the screen
- (right-col (+ scroll w-width)))
- (if (and (< col auto-show-show-left-margin-threshold)
- (< col (window-width))
- (> scroll 0))
- (scroll-right scroll)
- (if (< col scroll) ;to the left of the screen
- (scroll-right (+ (- scroll col) auto-show-shift-amount))
- (if (or (> col right-col) ;to the right of the screen
- (and (= col right-col)
- (not (eolp))))
- (scroll-left (+ auto-show-shift-amount
- (- col (+ scroll w-width))))
- )
- )
- )
- )
- )
- )
-
-;; Do auto-scrolling after commands.
-(add-hook 'post-command-hook 'auto-show-make-point-visible)
-
-;; Do auto-scrolling in comint buffers after process output also.
-(add-hook 'comint-output-filter-functions 'auto-show-make-point-visible t)
+ "This command is obsolete."
+ (interactive))
(provide 'auto-show)