-;;; scroll-bar.el --- window system-independent scroll bar support.
+;;; scroll-bar.el --- window system-independent scroll bar support
-;; Copyright (C) 1993, 1994, 1995 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994, 1995, 1999, 2000, 2001, 2002, 2003,
+;; 2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: hardware
;; This file is part of GNU Emacs.
-;; GNU Emacs is free software; you can redistribute it and/or modify
+;; GNU Emacs 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.
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs; see the file COPYING. If not, write to the
-;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; with a large scroll bar portion can easily overflow a lisp int.
(truncate (/ (* (float (car num-denom)) whole) (cdr num-denom))))
+(defun scroll-bar-columns (side)
+ "Return the width, measured in columns, of the vertical scrollbar on SIDE.
+SIDE must be the symbol `left' or `right'."
+ (let* ((wsb (window-scroll-bars))
+ (vtype (nth 2 wsb))
+ (cols (nth 1 wsb)))
+ (cond
+ ((not (memq side '(left right)))
+ (error "`left' or `right' expected instead of %S" side))
+ ((and (eq vtype side) cols))
+ ((eq (frame-parameter nil 'vertical-scroll-bars) side)
+ ;; nil means it's a non-toolkit scroll bar, and its width in
+ ;; columns is 14 pixels rounded up.
+ (ceiling (or (frame-parameter nil 'scroll-bar-width) 14)
+ (frame-char-width)))
+ (0))))
+
\f
;;;; Helpful functions for enabling and disabling scroll bars.
(defvar scroll-bar-mode)
+(defvar previous-scroll-bar-mode nil)
(defvar scroll-bar-mode-explicit nil
"Non-nil means `set-scroll-bar-mode' should really do something.
(defun set-scroll-bar-mode (value)
"Set `scroll-bar-mode' to VALUE and put the new value into effect."
+ (if scroll-bar-mode
+ (setq previous-scroll-bar-mode scroll-bar-mode))
+
(setq scroll-bar-mode value)
(when scroll-bar-mode-explicit
- ;; Apply it to default-frame-alist.
- (let ((parameter (assq 'vertical-scroll-bars default-frame-alist)))
- (if (consp parameter)
- (setcdr parameter scroll-bar-mode)
- (setq default-frame-alist
- (cons (cons 'vertical-scroll-bars scroll-bar-mode)
- default-frame-alist))))
-
- ;; Apply it to existing frames.
- (let ((frames (frame-list)))
- (while frames
- (modify-frame-parameters
- (car frames)
- (list (cons 'vertical-scroll-bars scroll-bar-mode)))
- (setq frames (cdr frames))))))
-
-(defcustom scroll-bar-mode
- (if (eq system-type 'windows-nt) 'right 'left)
- "*Specify whether to have vertical scroll bars, and on which side.
+ (modify-all-frames-parameters (list (cons 'vertical-scroll-bars
+ scroll-bar-mode)))))
+
+(defcustom scroll-bar-mode default-frame-scroll-bars
+ "Specify whether to have vertical scroll bars, and on which side.
Possible values are nil (no scroll bars), `left' (scroll bars on left)
and `right' (scroll bars on right).
To set this variable in a Lisp program, use `set-scroll-bar-mode'
to make it take real effect.
Setting the variable with a customization buffer also takes effect."
- :type '(choice (const :tag "none (nil)")
+ :type '(choice (const :tag "none (nil)" nil)
(const left)
(const right))
:group 'frames
+ ;; The default value for :initialize would try to use :set
+ ;; when processing the file in cus-dep.el.
+ :initialize 'custom-initialize-default
:set 'set-scroll-bar-mode-1)
;; We just set scroll-bar-mode, but that was the default.
;; If it is set again, that is for real.
(setq scroll-bar-mode-explicit t)
-(defun scroll-bar-mode (flag)
+(defun scroll-bar-mode (&optional flag)
"Toggle display of vertical scroll bars on all frames.
This command applies to all frames that exist and frames to be
created in the future.
-With a numeric argument, if the argument is negative,
-turn off scroll bars; otherwise, turn on scroll bars."
+With a numeric argument, if the argument is positive
+turn on scroll bars; otherwise turn off scroll bars."
(interactive "P")
- (if flag (setq flag (prefix-numeric-value flag)))
;; Tweedle the variable according to the argument.
- (set-scroll-bar-mode (if (null flag) (not scroll-bar-mode)
- (and (or (not (numberp flag)) (>= flag 0))
- (if (eq system-type 'windows-nt) 'right 'left)))))
+ (set-scroll-bar-mode (if (if (null flag)
+ (not scroll-bar-mode)
+ (setq flag (prefix-numeric-value flag))
+ (or (not (numberp flag)) (> flag 0)))
+ (or previous-scroll-bar-mode
+ default-frame-scroll-bars))))
(defun toggle-scroll-bar (arg)
"Toggle whether or not the selected frame has vertical scroll bars.
(selected-frame)
(list (cons 'vertical-scroll-bars
(if (> arg 0)
- (or scroll-bar-mode
- (if (eq system-type 'windows-nt) 'right 'left)))))))
+ (or scroll-bar-mode default-frame-scroll-bars))))))
(defun toggle-horizontal-scroll-bar (arg)
"Toggle whether or not the selected frame has horizontal scroll bars.
\f
;;;; Buffer navigation using the scroll bar.
-;;; This was used for up-events on button 2, but no longer.
+;; This was used for up-events on button 2, but no longer.
(defun scroll-bar-set-window-start (event)
"Set the window start according to where the scroll bar is dragged.
EVENT should be a scroll bar click or drag event."
(let* ((end-position (event-end event))
(window (nth 0 end-position))
(portion-whole (nth 2 end-position)))
- (save-excursion
- (set-buffer (window-buffer window))
+ (with-current-buffer (window-buffer window)
(save-excursion
(goto-char (+ (point-min)
(scroll-bar-scale portion-whole
portion-start
next-portion-start
(current-start (window-start window)))
- (save-excursion
- (set-buffer (window-buffer window))
+ (with-current-buffer (window-buffer window)
(setq portion-start (scroll-bar-drag-position portion-whole))
(setq next-portion-start (max
(scroll-bar-drag-position next-portion-whole)
(let* ((start-position (event-start event))
(window (nth 0 start-position))
(portion-whole (nth 2 start-position)))
- (save-excursion
- (set-buffer (window-buffer window))
- ;; Calculate position relative to the accessible part of the buffer.
- (goto-char (+ (point-min)
- (scroll-bar-scale portion-whole
- (- (point-max) (point-min)))))
- (beginning-of-line)
- (set-window-start window (point)))))
+ (save-excursion
+ (with-current-buffer (window-buffer window)
+ ;; Calculate position relative to the accessible part of the buffer.
+ (goto-char (+ (point-min)
+ (scroll-bar-scale portion-whole
+ (- (point-max) (point-min)))))
+ (vertical-motion 0 window)
+ (set-window-start window (point))))))
(defun scroll-bar-drag (event)
"Scroll the window by dragging the scroll bar slider.
\f
;;; Tookit scroll bars.
-;; Due to its event handling, Emacs is currently not able to handle Xt
-;; timeouts which toolkit scroll bars use to implement auto-repeat.
-;; As a workaround, we start a timer whenever a scroll bar action
-;; occurs, and remove it again when are notified that the user no
-;; longer interacts with the scroll bar. The timer function gives Xt
-;; the chance to call Xt timeout functions.
-
-(defvar scroll-bar-timer nil
- "Timer running while scroll bar is active.")
-
(defun scroll-bar-toolkit-scroll (event)
(interactive "e")
(let* ((end-position (event-end event))
(window (nth 0 end-position))
(part (nth 4 end-position))
before-scroll)
- (cond ((eq part 'end-scroll)
- (when scroll-bar-timer
- (cancel-timer scroll-bar-timer)
- (setq scroll-bar-timer nil)))
+ (cond ((eq part 'end-scroll))
(t
(with-current-buffer (window-buffer window)
(setq before-scroll point-before-scroll))
(scroll-up '-))
((eq part 'below-handle)
(scroll-up nil))
+ ((eq part 'ratio)
+ (let* ((portion-whole (nth 2 end-position))
+ (lines (scroll-bar-scale portion-whole
+ (1- (window-height)))))
+ (scroll-up (cond ((not (zerop lines)) lines)
+ ((< (car portion-whole) 0) -1)
+ (t 1)))))
((eq part 'up)
(scroll-up -1))
((eq part 'down)
((eq part 'handle)
(scroll-bar-drag-1 event))))
(sit-for 0)
- (unless scroll-bar-timer
- (setq scroll-bar-timer
- (run-with-timer 0.1 0.1 'xt-process-timeouts)))
(with-current-buffer (window-buffer window)
(setq point-before-scroll before-scroll))))))
\f
;;;; Bindings.
-;;; For now, we'll set things up to work like xterm.
-(cond (x-toolkit-scroll-bars-p
+;; For now, we'll set things up to work like xterm.
+(cond ((and (boundp 'x-toolkit-scroll-bars) x-toolkit-scroll-bars)
(global-set-key [vertical-scroll-bar mouse-1]
'scroll-bar-toolkit-scroll))
(t
\f
(provide 'scroll-bar)
+;; arch-tag: 6f1d01d0-0b1e-4bf8-86db-d491e0f399f3
;;; scroll-bar.el ends here