X-Git-Url: https://code.delx.au/gnu-emacs/blobdiff_plain/dc14eed224c67066438020372003b156afd211ae..b336bfcdf39f1e4d35bff4a7bd01d3b4bca8f516:/lisp/scroll-bar.el diff --git a/lisp/scroll-bar.el b/lisp/scroll-bar.el index 7417218320..3f763fc59d 100644 --- a/lisp/scroll-bar.el +++ b/lisp/scroll-bar.el @@ -1,134 +1,360 @@ -;;; scrollbar.el -- window system-independent scrollbar 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, 2002, 2003, +;; 2004, 2005, 2006, 2007, 2008, 2009, 2010 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 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 -;;; 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. If not, see . + +;;; Commentary: + +;; Window-system-independent bindings of mouse clicks on the scroll bar. +;; Presently emulates the scroll-bar behavior of xterm. + +;;; Code: (require 'mouse) ;;;; Utilities. -(defun scrollbar-scale (num-denom whole) +(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 scrollbar into real units, -like buffer positions. If SCROLLBAR-POS is the (PORTION . WHOLE) pair -from a scrollbar event, then (scrollbar-scale SCROLLBAR-POS +This is handy for scaling a position on a scroll bar into real units, +like buffer positions. If SCROLL-BAR-POS is the (PORTION . WHOLE) pair +from a scroll bar event, then (scroll-bar-scale SCROLL-BAR-POS \(buffer-size)) is the position in the current buffer corresponding to -that scrollbar position." +that scroll bar position." ;; We multiply before we divide to maintain precision. ;; We use floating point because the product of a large buffer size - ;; with a large scrollbar portion can easily overflow a lisp int. + ;; 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)))) + ;;;; Helpful functions for enabling and disabling scroll bars. -(defvar scroll-bar-mode nil) -(defun scroll-bar-mode (flag) - "Toggle display of vertical scroll bars on each frame. +(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. +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." + (if scroll-bar-mode + (setq previous-scroll-bar-mode scroll-bar-mode)) + + (setq scroll-bar-mode value) + + (when scroll-bar-mode-explicit + (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)" 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 (&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") + + ;; Tweedle the variable according to the argument. + (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. +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 default-frame-scroll-bars)))))) + +(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") - (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-scrollbars horizontal-scrollbars)) - (let ((frames (frame-list))) - (while frames - (modify-frame-parameters - (car frames) - (list (cons 'vertical-scrollbars scroll-bar-mode) - (cons 'horizontal-scrollbars scroll-bar-mode))) - (setq frames (cdr frames))))) + (error "Horizontal scroll bars aren't implemented yet")) -;;;; Buffer navigation using the scrollbar. +;;;; Buffer navigation using the scroll bar. -(defun scrollbar-set-window-start (event) - "Set the window start according to where the scrollbar is dragged. -EVENT should be a scrollbar click or drag event." +;; 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." (interactive "e") (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 (scrollbar-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 scrollbar-scroll-down (event) - "Scroll the window's top line down to the location of the scrollbar click. -EVENT should be a scrollbar click." +(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))) + (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) + (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 + (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. +If you click outside the slider, the window scrolls to bring the slider there." (interactive "e") - (let ((old-selected-window (selected-window))) + (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* ((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 - (scrollbar-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 scrollbar-scroll-up (event) - "Scroll the line next to the scrollbar click to the top of the window. -EVENT should be a scrollbar click." +(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 - (scrollbar-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))))) -;;;; Bindings. +;;; 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)))))) + -;;; For now, we'll set things up to work like xterm. -(global-set-key [vertical-scrollbar mouse-1] 'scrollbar-scroll-up) -(global-set-key [vertical-scrollbar drag-mouse-1] 'scrollbar-scroll-up) + +;;;; Bindings. -(global-set-key [vertical-scrollbar mouse-2] 'scrollbar-set-window-start) -(global-set-key [vertical-scrollbar drag-mouse-2] 'scrollbar-set-window-start) - -(global-set-key [vertical-scrollbar mouse-3] 'scrollbar-scroll-down) -(global-set-key [vertical-scrollbar drag-mouse-3] 'scrollbar-scroll-down) +;; 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))) (provide 'scroll-bar) -;;; scrollbar.el ends here +;; arch-tag: 6f1d01d0-0b1e-4bf8-86db-d491e0f399f3 +;;; scroll-bar.el ends here