Merge from emacs--devo--0

[gnu-emacs] / lisp / scroll-bar.el

diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el
index 609bea4ab9cb68d76c073e370fd55b528a1cf0b3..0a373058f667d48a2ddba213c06a5e714eb20003 100644 (file)
--- a/lisp/scroll-bar.el
+++ b/lisp/scroll-bar.el
@@ -1,7 +1,7 @@
 ;;; 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, 2006, 2007 Free Software Foundation, Inc.
 
 ;; Maintainer: FSF
 ;; Keywords: hardware
@@ -10,7 +10,7 @@
 
 ;; 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)
+;; the Free Software Foundation; either version 3, or (at your option)
 ;; any later version.
 
 ;; GNU Emacs is distributed in the hope that it will be useful,
@@ -20,8 +20,8 @@
 
 ;; 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:
 
@@ -54,10 +54,28 @@ that scroll bar position."
   ;; 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.
@@ -68,29 +86,16 @@ This is nil while loading `scroll-bar.el', and t afterward.")
 
 (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
-  (cond ((eq system-type 'windows-nt) 'right)
-       ((featurep 'mac-carbon) 'right)
-       (t 'left))
+    (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).
@@ -117,14 +122,14 @@ created in the future.
 With a numeric argument, if the argument is negative,
 turn off scroll bars; otherwise, turn on 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))
-                             (cond ((eq system-type 'windows-nt) 'right)
-                                   ((featurep 'mac-carbon) 'right)
-                                   (t '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.
@@ -142,10 +147,7 @@ when they are turned on; if it is nil, they go on the left."
    (selected-frame)
    (list (cons 'vertical-scroll-bars
               (if (> arg 0)
-                  (or scroll-bar-mode
-                      (cond ((eq system-type 'windows-nt) 'right)
-                            ((featurep 'mac-carbon) 'right)
-                            (t '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.
@@ -358,4 +360,5 @@ EVENT should be a scroll bar click."
 \f
 (provide 'scroll-bar)
 
+;;; arch-tag: 6f1d01d0-0b1e-4bf8-86db-d491e0f399f3
 ;;; scroll-bar.el ends here