-;; LCD Archive Entry:
-;; auto-show|Pete Ware|ware@cis.ohio-state.edu|
-;; Automatically scroll horizontally|
-;; 95-02-24|1.9|~/misc/auto-show.el|
-;;
-;;;
-;;; Author:
-;;;
-;;; Pete Ware ware@cis.ohio-state.edu
-;;; CIS Dept, Ohio State University w/ (614) 292-8501
-;;; 774 Dreese, 2015 Neil Ave. h/ (614) 791-1347
-;;; Columbus, OH 43210 http://www.cis.ohio-state.edu/~ware
-;;;
-;;;
-;;; Modification history:
-;;; 02/24/95 Added auto-show-show-left-margin-threshold so that if
-;;; there is anyway for the left margin to be displayed it is.
-;;; 02/24/95 Only scroll window if it matches current buffer. Added
-;;; function for enabeling scrolling in comint buffers on output.
-;;; 02/13/95 Aded Kevin Broadey <KevinB@bartley.demon.co.uk> fix so that
-;;; it doesn't scroll if we are at window border and at the
-;;; end of the line (i.e. newline character)
-;;; 02/10/95 jeff.dwork@amd.com added auto-show-toggle function.
-;;; 02/08/95 Added auto-show-enable as per
-;;; jeff.dwork@amd.com (Jeff Dwork)'s suggestion. Cleaned up
-;;; documentation.
-;;; 02/07/95 Rewrote for emacs 19: much, much cleaner. Renamed auto-show
-;;; 8/6/90 Make next-line/previous-line do better job following movement.
-;;; 3/21/90 better calculation of w-width in e-make-point-visible
-;;; test for truncated windows
-;;; added substitute-in-keymap
-;;; renamed to auto-horizontal
-;;; added backward-delete-char
-;;; 8/13/88 Created
+;;; This file is in the public domain.
-;;;
-;;; This is a rewrite of auto-horizontal. It is comparable in
-;;; functionality to hscroll.el except it is not a minor mode and does
-;;; not use any timers. This file provides functions that
+;;; Keywords: scroll display minor-mode
+;;; 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. To load it just add:
-;;; (require 'auto-show)
-;;; to your .emacs.
-;;;
-;;; Setting the variable ``truncate-lines'' to non-nil causes long
-;;; lines to disappear off the end of the screen instead of wrapping
-;;; to the beginning of the next line. To make this the default for
-;;; all buffers add the following line to your .emacs (sans ;;;):
+;;; 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)
-;;;
-;;; However, I've found that I only want this when I'm editing C code.
-;;; Accordingly I have something like the following in my .emacs:
+;;; 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 ()
;;; (add-hook 'c-mode-hook 'my-c-mode-hook)
;;;
;;;
-;;; As a finer level of control, one can still have truncated lines but
-;;; without the automatic left and right scrolling by setting the buffer
-;;; local variable ``auto-show-enable'' to nil. The default value is t.
-;;; The command ``auto-show-toggle'' will toggle the value of
-;;; ``auto-show-enable''.
-;;;
-;;;
-;;; I also like the output from my shell's (and other comint.el based commands)
-;;; to scroll on output. One can call:
-;;;
-;;; (auto-show-comint-make-point-visible)
-;;;
-;;; which adds auto-show-make-point-visible to comint-output-filter-functions.
-
-(provide 'auto-show)
-
-;;;************************************************************
-;;;*
-;;;* Define Automatic Horizontal Scrolling Functions
-;;;*
-;;;************************************************************
+;;; 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'.
-(add-hook 'post-command-hook 'auto-show-make-point-visible)
+;;; Code:
-(defvar auto-show-enable t
- "*Allows one to turn off automatic horizontal scrolling on a per buffer
-basis independent of whether truncate-lines is t. The default value is t.
-To change the default:
- (set-default 'auto-show-enable nil)
-Any time auto-show-enable is changed it is only in the current buffer:
- (setq auto-show-enable nil)
-turns it on for this buffer.
-See also command `auto-show-toggle'.")
+(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-enable)
+(make-variable-buffer-local 'auto-show-mode)
(defvar auto-show-shift-amount 8
- "*Extra amount to shift a line when point is not visible.")
+ "*Extra columns to scroll. for automatic horizontal scrolling.")
(defvar auto-show-show-left-margin-threshold 50
- "*Point must be before this column for us to try and make the left margin
+ "*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 truncation is on for current window."
+ "True if line truncation is enabled for the selected window."
(or truncate-lines
(and truncate-partial-width-windows
(< (window-width) (frame-width)))))
-(defun auto-show-toggle ()
- "Toggle value of auto-show-enable."
- (interactive)
- (setq auto-show-enable (not auto-show-enable)))
+;;;###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))))
(defun auto-show-make-point-visible (&optional ignore-arg)
- "Scrolls the screen horizontally to make point visible but only if
-auto-show-enable is non-nil and lines are truncated. See also variable
-`auto-show-enable' and command `auto-show-toggle'."
+ "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-enable (auto-show-truncationp)
+ (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
)
)
-(defun auto-show-comint-make-point-visible ()
- "Add a function to comint-output-filter-functions that auto-scrolls
-left or right on output to the buffer.
+;; Do auto-scrolling after commands.
+(add-hook 'post-command-hook 'auto-show-make-point-visible)
-NOTE: you should load comint mode before this as comint.el uses a
-defvar to initialize comint-output-filter-functions to the default value."
- (interactive)
- (add-hook 'comint-output-filter-functions 'auto-show-make-point-visible t)
- )
+;; Do auto-scrolling in comint buffers after process output also.
+(add-hook 'comint-output-filter-functions 'auto-show-make-point-visible t)
+
+(provide 'auto-show)
-;; end of auto-show.el
+;; auto-show.el ends here
projects / emacs.git / commitdiff