;;; scroll-bar.el --- window system-independent scroll bar support
-;; Copyright (C) 1993, 1994, 1995, 1999, 2000, 2001, 2003
-;; Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994, 1995, 1999, 2000, 2001, 2002, 2003,
+;; 2004, 2005 Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: hardware
;; 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.
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
;;; 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.