-;;; scroll-bar.el -- window system-independent scroll bar support.
+;;; scroll-bar.el --- window system-independent scroll bar support
-;;; Copyright (C) 1993 Free Software Foundation, Inc.
+;; Copyright (C) 1993, 1994, 1995, 1999, 2000, 2001
+;; Free Software Foundation, Inc.
;; Maintainer: FSF
;; Keywords: hardware
-;;; This file is part of GNU Emacs.
+;; This file is part of GNU Emacs.
-;;; 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.
+;; 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.
-;;; GNU Emacs is distributed in the hope that it will be useful,
-;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-;;; GNU General Public License for more details.
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; 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.
+
+;;; Commentary:
+
+;; Window-system-independent bindings of mouse clicks on the scroll bar.
+;; Presently emulates the scroll-bar behavior of xterm.
+
+;;; Code:
(require 'mouse)
\f
;;;; Utilities.
+(defun scroll-bar-event-ratio (event)
+ "Given a scroll bar event EVENT, return the scroll bar position as a ratio.
+The value is a cons cell (PORTION . WHOLE) containing two integers
+whose ratio gives the event's vertical position in the scroll bar, with 0
+referring to the top and 1 to the bottom."
+ (nth 2 event))
+
(defun scroll-bar-scale (num-denom whole)
"Given a pair (NUM . DENOM) and WHOLE, return (/ (* NUM WHOLE) DENOM).
This is handy for scaling a position on a scroll bar into real units,
\f
;;;; Helpful functions for enabling and disabling scroll bars.
-(defvar scroll-bar-mode nil)
+
+(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)
+
+ (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.
+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)")
+ (const left)
+ (const right))
+ :group 'frames
+ :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)
- "Toggle display of vertical scroll bars on each frame.
+ "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."
(interactive "P")
- (setq scroll-bar-mode (if (null flag) (not scroll-bar-mode)
- (or (not (numberp flag)) (>= flag 0))))
- (mapcar
- (function
- (lambda (param-name)
- (let ((parameter (assq param-name default-frame-alist)))
- (if (consp parameter)
- (setcdr parameter scroll-bar-mode)
- (setq default-frame-alist
- (cons (cons param-name scroll-bar-mode)
- default-frame-alist))))))
- '(vertical-scroll-bars horizontal-scroll-bars))
- (let ((frames (frame-list)))
- (while frames
- (modify-frame-parameters
- (car frames)
- (list (cons 'vertical-scroll-bars scroll-bar-mode)
- (cons 'horizontal-scroll-bars scroll-bar-mode)))
- (setq frames (cdr frames)))))
+ (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)))))
+
+(defun toggle-scroll-bar (arg)
+ "Toggle whether or not the selected frame has vertical scroll bars.
+With arg, turn vertical scroll bars on if and only if arg is positive.
+The variable `scroll-bar-mode' controls which side the scroll bars are on
+when they are turned on; if it is nil, they go on the left."
+ (interactive "P")
+ (if (null arg)
+ (setq arg
+ (if (cdr (assq 'vertical-scroll-bars
+ (frame-parameters (selected-frame))))
+ -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
+ (if (eq system-type 'windows-nt) 'right 'left)))))))
+
+(defun toggle-horizontal-scroll-bar (arg)
+ "Toggle whether or not the selected frame has horizontal scroll bars.
+With arg, turn horizontal scroll bars on if and only if arg is positive.
+Horizontal scroll bars aren't implemented yet."
+ (interactive "P")
+ (error "Horizontal scroll bars aren't implemented yet"))
\f
;;;; Buffer navigation using the scroll bar.
+;;; 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."
(save-excursion
(set-buffer (window-buffer window))
(save-excursion
- (goto-char (scroll-bar-scale portion-whole (buffer-size)))
+ (goto-char (+ (point-min)
+ (scroll-bar-scale portion-whole
+ (- (point-max) (point-min)))))
(beginning-of-line)
(set-window-start window (point))))))
+(defun scroll-bar-drag-position (portion-whole)
+ "Calculate new window start for drag event."
+ (save-excursion
+ (goto-char (+ (point-min)
+ (scroll-bar-scale portion-whole
+ (- (point-max) (point-min)))))
+ (beginning-of-line)
+ (point)))
+
+(defun scroll-bar-maybe-set-window-start (event)
+ "Set the window start according to where the scroll bar is dragged.
+Only change window start if the new start is substantially different.
+EVENT should be a scroll bar click or drag event."
+ (interactive "e")
+ (let* ((end-position (event-end event))
+ (window (nth 0 end-position))
+ (portion-whole (nth 2 end-position))
+ (next-portion-whole (cons (1+ (car portion-whole))
+ (cdr portion-whole)))
+ portion-start
+ next-portion-start
+ (current-start (window-start window)))
+ (save-excursion
+ (set-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)
+ (1+ 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.
+ (set-window-start window current-start)))))
+
+;; Scroll the window to the proper position for EVENT.
+(defun scroll-bar-drag-1 (event)
+ (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)))))
+
+(defun scroll-bar-drag (event)
+ "Scroll the window by dragging the scroll bar slider.
+If you click outside the slider, the window scrolls to bring the slider there."
+ (interactive "e")
+ (let* (done
+ (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)))
+ (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))))))
- (select-window old-selected-window))))
+ (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)))
+ (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))))))
- (select-window old-selected-window))))
+ (scroll-bar-scale portion-whole (1- (window-height)))))
+ (sit-for 0))
+ (with-current-buffer (window-buffer window)
+ (setq point-before-scroll before-scroll)))))
+
+\f
+;;; Tookit scroll bars.
+
+(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))))))
+
\f
;;;; Bindings.
;;; 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)
-
-(global-set-key [vertical-scroll-bar mouse-2] 'scroll-bar-set-window-start)
-(global-set-key [vertical-scroll-bar drag-mouse-2] 'scroll-bar-set-window-start)
-
-(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)
+(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)
HCoop / bpt / emacs.git / blobdiff