-;;; 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
+;; Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: hardware
\f
;;;; Helpful functions for enabling and disabling scroll bars.
-(defun set-scroll-bar-mode (ignore value)
+(defvar scroll-bar-mode)
+
+(defvar scroll-bar-mode-explicit nil
+ "Non-nil means `set-scroll-bar-mode' should really do something.
+This is nil while loading `scroll-bar.el', and t afterward.")
+
+(defun set-scroll-bar-mode-1 (ignore value)
+ (set-scroll-bar-mode value))
+
+(defun set-scroll-bar-mode (value)
"Set `scroll-bar-mode' to VALUE and put the new value into effect."
(setq scroll-bar-mode value)
- ;; 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 'left
+ (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))
"*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).
-When you set the variable in a Lisp program, it takes effect for new frames,
-and for existing frames when `toggle-scroll-bar' is used.
-When you set this with the customization buffer,
-it takes effect immediately for all frames."
+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)")
(const left)
(const right))
:group 'frames
- :set 'set-scroll-bar-mode)
+ ;; 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)
-(defun scroll-bar-mode (flag)
+;; 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 (&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.
(if flag (setq flag (prefix-numeric-value flag)))
;; Tweedle the variable according to the argument.
- (set-scroll-bar-mode nil
- (if (null flag) (not scroll-bar-mode)
+ (set-scroll-bar-mode (if (null flag) (not scroll-bar-mode)
(and (or (not (numberp flag)) (>= flag 0))
- 'left))))
+ (cond ((eq system-type 'windows-nt) 'right)
+ ((featurep 'mac-carbon) 'right)
+ (t 'left))))))
(defun toggle-scroll-bar (arg)
"Toggle whether or not the selected frame has vertical scroll bars.
(setq arg
(if (cdr (assq 'vertical-scroll-bars
(frame-parameters (selected-frame))))
- -1 1)))
- (modify-frame-parameters (selected-frame)
- (list (cons 'vertical-scroll-bars
- (if (> arg 0)
- (or scroll-bar-mode 'left))))))
+ -1 1))
+ (setq arg (prefix-numeric-value arg)))
+ (modify-frame-parameters
+ (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))))))))
(defun toggle-horizontal-scroll-bar (arg)
"Toggle whether or not the selected frame has horizontal scroll bars.
(setq next-portion-start (max
(scroll-bar-drag-position next-portion-whole)
(1+ portion-start)))
- (if (or (> current-start next-portion-start)
+ (if (or (>= current-start next-portion-start)
(< current-start portion-start))
(set-window-start window portion-start)
;; Always set window start, to ensure scroll bar position is updated.
If you click outside the slider, the window scrolls to bring the slider there."
(interactive "e")
(let* (done
- (echo-keystrokes 0))
- (or point-before-scroll
- (setq point-before-scroll (point)))
- ;; Our scrolling can move point; don't let that clear point-before-scroll.
- (let (point-before-scroll)
- (scroll-bar-drag-1 event)
- (track-mouse
- (while (not done)
- (setq event (read-event))
- (if (eq (car-safe event) 'mouse-movement)
- (setq event (read-event)))
- (cond ((eq (car-safe event) 'scroll-bar-movement)
- (scroll-bar-drag-1 event))
- (t
- ;; Exit when we get the drag event; ignore that event.
- (setq done t)))))
- (sit-for 0))))
+ (echo-keystrokes 0)
+ (end-position (event-end event))
+ (window (nth 0 end-position))
+ (before-scroll))
+ (with-current-buffer (window-buffer window)
+ (setq before-scroll point-before-scroll))
+ (save-selected-window
+ (select-window window)
+ (setq before-scroll
+ (or before-scroll (point))))
+ (scroll-bar-drag-1 event)
+ (track-mouse
+ (while (not done)
+ (setq event (read-event))
+ (if (eq (car-safe event) 'mouse-movement)
+ (setq event (read-event)))
+ (cond ((eq (car-safe event) 'scroll-bar-movement)
+ (scroll-bar-drag-1 event))
+ (t
+ ;; Exit when we get the drag event; ignore that event.
+ (setq done t)))))
+ (sit-for 0)
+ (with-current-buffer (window-buffer window)
+ (setq point-before-scroll before-scroll))))
(defun scroll-bar-scroll-down (event)
"Scroll the window's top line down to the location of the scroll bar click.
EVENT should be a scroll bar click."
(interactive "e")
- (let ((old-selected-window (selected-window)))
+ (let* ((end-position (event-end event))
+ (window (nth 0 end-position))
+ (before-scroll))
+ (with-current-buffer (window-buffer window)
+ (setq before-scroll point-before-scroll))
(unwind-protect
- (progn
- (let* ((end-position (event-end event))
- (window (nth 0 end-position))
- (portion-whole (nth 2 end-position)))
- (let (point-before-scroll)
- (select-window window))
- (or point-before-scroll
- (setq point-before-scroll (point)))
- (let (point-before-scroll)
- (scroll-down
- (scroll-bar-scale portion-whole (1- (window-height)))))))
- (select-window old-selected-window))))
+ (save-selected-window
+ (let ((portion-whole (nth 2 end-position)))
+ (select-window window)
+ (setq before-scroll
+ (or before-scroll (point)))
+ (scroll-down
+ (scroll-bar-scale portion-whole (1- (window-height)))))
+ (sit-for 0))
+ (with-current-buffer (window-buffer window)
+ (setq point-before-scroll before-scroll)))))
(defun scroll-bar-scroll-up (event)
"Scroll the line next to the scroll bar click to the top of the window.
EVENT should be a scroll bar click."
(interactive "e")
- (let ((old-selected-window (selected-window)))
+ (let* ((end-position (event-end event))
+ (window (nth 0 end-position))
+ (before-scroll))
+ (with-current-buffer (window-buffer window)
+ (setq before-scroll point-before-scroll))
(unwind-protect
- (progn
- (let* ((end-position (event-end event))
- (window (nth 0 end-position))
- (portion-whole (nth 2 end-position)))
- (let (point-before-scroll)
- (select-window window))
- (or point-before-scroll
- (setq point-before-scroll (point)))
- (let (point-before-scroll)
- (scroll-up
- (scroll-bar-scale portion-whole (1- (window-height)))))))
- (select-window old-selected-window))))
+ (save-selected-window
+ (let ((portion-whole (nth 2 end-position)))
+ (select-window window)
+ (setq before-scroll
+ (or before-scroll (point)))
+ (scroll-up
+ (scroll-bar-scale portion-whole (1- (window-height)))))
+ (sit-for 0))
+ (with-current-buffer (window-buffer window)
+ (setq point-before-scroll before-scroll)))))
\f
-;;;; Bindings.
+;;; Tookit scroll bars.
-;;; For now, we'll set things up to work like xterm.
-(global-set-key [vertical-scroll-bar mouse-1] 'scroll-bar-scroll-up)
-(global-set-key [vertical-scroll-bar drag-mouse-1] 'scroll-bar-scroll-up)
+(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))
+ (t
+ (with-current-buffer (window-buffer window)
+ (setq before-scroll point-before-scroll))
+ (save-selected-window
+ (select-window window)
+ (setq before-scroll (or before-scroll (point)))
+ (cond ((eq part 'above-handle)
+ (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)
+ (scroll-up 1))
+ ((eq part 'top)
+ (set-window-start window (point-min)))
+ ((eq part 'bottom)
+ (goto-char (point-max))
+ (recenter))
+ ((eq part 'handle)
+ (scroll-bar-drag-1 event))))
+ (sit-for 0)
+ (with-current-buffer (window-buffer window)
+ (setq point-before-scroll before-scroll))))))
-(global-set-key [vertical-scroll-bar down-mouse-2] 'scroll-bar-drag)
-(global-set-key [vertical-scroll-bar mouse-3] 'scroll-bar-scroll-down)
-(global-set-key [vertical-scroll-bar drag-mouse-3] 'scroll-bar-scroll-down)
+\f
+;;;; Bindings.
+
+;;; 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
+ (global-set-key [vertical-scroll-bar mouse-1]
+ 'scroll-bar-scroll-up)
+ (global-set-key [vertical-scroll-bar drag-mouse-1]
+ 'scroll-bar-scroll-up)
+ (global-set-key [vertical-scroll-bar down-mouse-2]
+ 'scroll-bar-drag)
+ (global-set-key [vertical-scroll-bar mouse-3]
+ 'scroll-bar-scroll-down)
+ (global-set-key [vertical-scroll-bar drag-mouse-3]
+ 'scroll-bar-scroll-down)))
\f
(provide 'scroll-bar)