mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-04 08:47:11 +00:00
331 lines
12 KiB
EmacsLisp
331 lines
12 KiB
EmacsLisp
;;; mouse-drag.el --- use mouse-2 to do a new style of scrolling
|
|
|
|
;; Copyright (C) 1996, 1997, 2001, 2002, 2003, 2004,
|
|
;; 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
|
|
|
|
;; Author: John Heidemann <johnh@ISI.EDU>
|
|
;; Keywords: mouse
|
|
|
|
;; 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 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.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
;;; Commentary:
|
|
|
|
;; What is ``mouse-drag.el''?
|
|
;;
|
|
;; Doesn't that scroll bar seem far away when you want to scroll?
|
|
;; This module overloads mouse-2 to do ``throw'' scrolling. You
|
|
;; click and drag. The distance you move from your original click
|
|
;; turns into a scroll amount. The scroll amount is scaled
|
|
;; exponentially to make both large moves and short adjustments easy.
|
|
;; What this boils down to is that you can easily scroll around the
|
|
;; buffer without much mouse movement. Finally, clicks which aren't
|
|
;; drags are passed off to the old mouse-2 binding, so old mouse-2
|
|
;; operations (find-file in dired-mode, yanking in most other modes)
|
|
;; still work.
|
|
;;
|
|
;; There is an alternative way to scroll, ``drag'' scrolling. You
|
|
;; can click on a character and then drag it around, scrolling the
|
|
;; buffer with you. The character always stays under the mouse.
|
|
;; Compared to throw-scrolling, this approach provides direct
|
|
;; manipulation (nice) but requires more mouse movement
|
|
;; (unfortunate). It is offered as an alternative for those who
|
|
;; prefer it.
|
|
;;
|
|
;; If you like mouse-drag, you should also check out mouse-copy
|
|
;; for ``one-click text copy and move''.
|
|
;;
|
|
;; To use mouse-drag, place the following in your .emacs file:
|
|
;; -either-
|
|
;; (global-set-key [down-mouse-2] 'mouse-drag-throw)
|
|
;; -or-
|
|
;; (global-set-key [down-mouse-2] 'mouse-drag-drag)
|
|
;;
|
|
;;
|
|
;;
|
|
;; Options:
|
|
;;
|
|
;; - reverse the throw-scroll direction with \\[mouse-throw-with-scroll-bar]
|
|
;; - work around a bug with \\[mouse-extras-work-around-drag-bug]
|
|
;; - auto-enable horizontal scrolling with
|
|
;; \\[mouse-drag-electric-col-scrolling]
|
|
;;
|
|
;;
|
|
;; History and related work:
|
|
;;
|
|
;; One-click copying and moving was inspired by lemacs-19.8.
|
|
;; Throw-scrolling was inspired by MacPaint's ``hand'' and by Tk's
|
|
;; mouse-2 scrolling. The package mouse-scroll.el by Tom Wurgler
|
|
;; <twurgler@goodyear.com> is similar to mouse-drag-throw, but
|
|
;; doesn't pass clicks through.
|
|
;;
|
|
;; These functions have been tested in emacs version 19.30,
|
|
;; and this package has run in the past on 19.25-19.29.
|
|
;;
|
|
;; Originally mouse-drag was part of a larger package.
|
|
;; As of 11 July 96 the scrolling functions were split out
|
|
;; in preparation for incorporation into (the future) emacs-19.32.
|
|
;;
|
|
;; Thanks:
|
|
;;
|
|
;; Thanks to Kai Grossjohann
|
|
;; <grossjoh@dusty.informatik.uni-dortmund.de> for reporting bugs, to
|
|
;; Tom Wurgler <twurgler@goodyear.com> for reporting bugs and
|
|
;; suggesting fixes, and to Joel Graber <jgraber@ti.com> for
|
|
;; prompting me to do drag-scrolling and for an initial
|
|
;; implementation of horizontal drag-scrolling.
|
|
;;
|
|
;; -johnh@isi.edu, 11-Jul-96
|
|
;;
|
|
;;
|
|
;; What's new with mouse-drag 2.24?
|
|
;;
|
|
;; - mouse-drag-electric-col-scrolling (default: on)
|
|
;; auto-enables horizontal scrolling when clicks on wrapped
|
|
;; lines occur
|
|
|
|
;; TODO:
|
|
;; - For mouse-drag-throw, we should try and place some visual indicator
|
|
;; of the original mouse position (like Firefox does).
|
|
|
|
;;; Code:
|
|
|
|
;;
|
|
;; scrolling code
|
|
;;
|
|
|
|
(defun mouse-drag-safe-scroll (row-delta &optional col-delta)
|
|
"Scroll down ROW-DELTA lines and right COL-DELTA, ignoring buffer edge errors.
|
|
Keep the cursor on the screen as needed."
|
|
(let ((scroll-preserve-screen-position nil))
|
|
(if (and row-delta
|
|
(/= 0 row-delta))
|
|
(condition-case nil ;; catch and ignore movement errors
|
|
(scroll-down row-delta)
|
|
(beginning-of-buffer (message "Beginning of buffer"))
|
|
(end-of-buffer (message "End of buffer"))))
|
|
(if (and col-delta
|
|
(/= 0 col-delta))
|
|
(progn
|
|
(scroll-right col-delta)
|
|
;; Make sure that the point stays on the visible screen
|
|
;; (if truncation-lines in set).
|
|
;; This code mimics the behavior we automatically get
|
|
;; when doing vertical scrolling.
|
|
;; Problem identified and a fix suggested by Tom Wurgler.
|
|
(cond
|
|
((< (current-column) (window-hscroll))
|
|
(move-to-column (window-hscroll))) ; make on left column
|
|
((> (- (current-column) (window-hscroll) (window-width) -2) 0)
|
|
(move-to-column (+ (window-width) (window-hscroll) -3))))))))
|
|
|
|
(defun mouse-drag-repeatedly-safe-scroll (row-delta &optional col-delta)
|
|
"Scroll ROW-DELTA rows and COL-DELTA cols until an event happens."
|
|
(while (sit-for mouse-scroll-delay)
|
|
(mouse-drag-safe-scroll row-delta col-delta)))
|
|
|
|
(defun mouse-drag-events-are-point-events-p (start-posn end-posn)
|
|
"Determine if START-POSN and END-POSN are \"close\"."
|
|
(let*
|
|
((start-col-row (posn-col-row start-posn))
|
|
(end-col-row (posn-col-row end-posn)))
|
|
(and
|
|
;; ;; We no longer exclude things by time.
|
|
;; (< (- (posn-timestamp end-posn) (posn-timestamp start-posn))
|
|
;; (if (numberp double-click-time)
|
|
;; (* 2 double-click-time) ;; stretch it a little
|
|
;; 999999)) ;; non-numeric => check by position alone
|
|
(= (car start-col-row) (car end-col-row))
|
|
(= (cdr start-col-row) (cdr end-col-row)))))
|
|
|
|
(defvar mouse-drag-electric-col-scrolling t
|
|
"If non-nil, mouse-drag on a long line enables truncate-lines.")
|
|
|
|
(defun mouse-drag-should-do-col-scrolling ()
|
|
"Determine if it's wise to enable col-scrolling for the current window.
|
|
Basically, we check for existing horizontal scrolling."
|
|
(or truncate-lines
|
|
(> (window-hscroll (selected-window)) 0)
|
|
(not (window-full-width-p))
|
|
(and
|
|
mouse-drag-electric-col-scrolling
|
|
(save-excursion ;; on a long line?
|
|
(let
|
|
((beg (progn (beginning-of-line) (point)))
|
|
(end (progn (end-of-line) (point))))
|
|
(if (> (- end beg) (window-width))
|
|
(setq truncate-lines t)
|
|
nil))))))
|
|
|
|
(defvar mouse-throw-with-scroll-bar nil
|
|
"*Set direction of mouse-throwing.
|
|
If nil, the text moves in the direction the mouse moves.
|
|
If t, the scroll bar moves in the direction the mouse moves.")
|
|
(defconst mouse-throw-magnifier-min -6)
|
|
(defconst mouse-throw-magnifier-max 6)
|
|
(defconst mouse-throw-magnifier-base 1.5)
|
|
|
|
(defun mouse-drag-scroll-delta (mouse-delta)
|
|
;; Limit the exponential explosion.
|
|
(setq mouse-delta
|
|
(max mouse-throw-magnifier-min
|
|
(min mouse-throw-magnifier-max mouse-delta)))
|
|
(* (round (exp (* (log mouse-throw-magnifier-base) (abs mouse-delta))))
|
|
(if (< mouse-delta 0) -1 1)
|
|
(if mouse-throw-with-scroll-bar 1 -1)))
|
|
|
|
;;;###autoload
|
|
(defun mouse-drag-throw (start-event)
|
|
"\"Throw\" the page according to a mouse drag.
|
|
|
|
A \"throw\" is scrolling the page at a speed relative to the distance
|
|
from the original mouse click to the current mouse location. Try it;
|
|
you'll like it. It's easier to observe than to explain.
|
|
|
|
If the mouse is clicked and released in the same place of time we
|
|
assume that the user didn't want to scdebugroll but wanted to whatever
|
|
mouse-2 used to do, so we pass it through.
|
|
|
|
Throw scrolling was inspired (but is not identical to) the \"hand\"
|
|
option in MacPaint, or the middle button in Tk text widgets.
|
|
|
|
If `mouse-throw-with-scroll-bar' is non-nil, then this command scrolls
|
|
in the opposite direction. (Different people have different ideas
|
|
about which direction is natural. Perhaps it has to do with which
|
|
hemisphere you're in.)
|
|
|
|
To test this function, evaluate:
|
|
(global-set-key [down-mouse-2] 'mouse-drag-throw)"
|
|
(interactive "e")
|
|
;; we want to do save-selected-window, but that requires 19.29
|
|
(let* ((start-posn (event-start start-event))
|
|
(start-window (posn-window start-posn))
|
|
(start-row (cdr (posn-col-row start-posn)))
|
|
(start-col (car (posn-col-row start-posn)))
|
|
(old-selected-window (selected-window))
|
|
event end row mouse-delta scroll-delta
|
|
have-scrolled
|
|
window-last-row
|
|
col mouse-col-delta window-last-col
|
|
(scroll-col-delta 0)
|
|
adjusted-mouse-col-delta
|
|
adjusted-mouse-delta
|
|
;; be conservative about allowing horizontal scrolling
|
|
(col-scrolling-p (mouse-drag-should-do-col-scrolling)))
|
|
(select-window start-window)
|
|
(track-mouse
|
|
(while (progn
|
|
(setq event (read-event)
|
|
end (event-end event)
|
|
row (cdr (posn-col-row end))
|
|
col (car (posn-col-row end)))
|
|
(or (mouse-movement-p event)
|
|
(eq (car-safe event) 'switch-frame)))
|
|
(when (eq start-window (posn-window end))
|
|
(when col-scrolling-p
|
|
(setq scroll-col-delta (mouse-drag-scroll-delta (- start-col col))))
|
|
(setq scroll-delta (mouse-drag-scroll-delta (- start-row row))))
|
|
|
|
(if (or (/= 0 scroll-delta)
|
|
(/= 0 scroll-col-delta))
|
|
(progn
|
|
(setq have-scrolled t)
|
|
(mouse-drag-safe-scroll scroll-delta scroll-col-delta)
|
|
(mouse-drag-repeatedly-safe-scroll scroll-delta scroll-col-delta))))) ;xxx
|
|
;; If it was a click and not a drag, prepare to pass the event on.
|
|
;; Is there a more correct way to reconstruct the event?
|
|
(if (and (not have-scrolled)
|
|
(mouse-drag-events-are-point-events-p start-posn end))
|
|
(push (cons (event-basic-type start-event) (cdr start-event))
|
|
unread-command-events))
|
|
;; Now restore the old window.
|
|
(select-window old-selected-window)))
|
|
|
|
;;;###autoload
|
|
(defun mouse-drag-drag (start-event)
|
|
"\"Drag\" the page according to a mouse drag.
|
|
|
|
Drag scrolling moves the page according to the movement of the mouse.
|
|
You \"grab\" the character under the mouse and move it around.
|
|
|
|
If the mouse is clicked and released in the same place of time we
|
|
assume that the user didn't want to scroll but wanted to whatever
|
|
mouse-2 used to do, so we pass it through.
|
|
|
|
Drag scrolling is identical to the \"hand\" option in MacPaint, or the
|
|
middle button in Tk text widgets.
|
|
|
|
To test this function, evaluate:
|
|
(global-set-key [down-mouse-2] 'mouse-drag-drag)"
|
|
(interactive "e")
|
|
;; we want to do save-selected-window, but that requires 19.29
|
|
(let* ((start-posn (event-start start-event))
|
|
(start-window (posn-window start-posn))
|
|
(start-row (cdr (posn-col-row start-posn)))
|
|
(start-col (car (posn-col-row start-posn)))
|
|
(old-selected-window (selected-window))
|
|
event end row mouse-delta scroll-delta
|
|
have-scrolled
|
|
window-last-row
|
|
col mouse-col-delta window-last-col
|
|
(scroll-col-delta 0)
|
|
;; be conservative about allowing horizontal scrolling
|
|
(col-scrolling-p (mouse-drag-should-do-col-scrolling)))
|
|
(select-window start-window)
|
|
(setq window-last-row (- (window-height) 2)
|
|
window-last-col (- (window-width) 2))
|
|
(track-mouse
|
|
(while (progn
|
|
(setq event (read-event)
|
|
end (event-end event)
|
|
row (cdr (posn-col-row end))
|
|
col (car (posn-col-row end)))
|
|
(or (mouse-movement-p event)
|
|
(eq (car-safe event) 'switch-frame)))
|
|
;; Scroll if see if we're on the edge.
|
|
;; NEEDSWORK: should handle mouse-in-other window.
|
|
(cond
|
|
((not (eq start-window (posn-window end)))
|
|
t) ; wait for return to original window
|
|
((<= row 0) (mouse-drag-repeatedly-safe-scroll -1 0))
|
|
((>= row window-last-row) (mouse-drag-repeatedly-safe-scroll 1 0))
|
|
((and col-scrolling-p (<= col 1)) (mouse-drag-repeatedly-safe-scroll 0 -1))
|
|
((and col-scrolling-p (>= col window-last-col)) (mouse-drag-repeatedly-safe-scroll 0 1))
|
|
(t
|
|
(setq scroll-delta (- row start-row)
|
|
start-row row)
|
|
(if col-scrolling-p
|
|
(setq scroll-col-delta (- col start-col)
|
|
start-col col))
|
|
(if (or (/= 0 scroll-delta)
|
|
(/= 0 scroll-col-delta))
|
|
(progn
|
|
(setq have-scrolled t)
|
|
(mouse-drag-safe-scroll scroll-delta scroll-col-delta)))))))
|
|
;; If it was a click and not a drag, prepare to pass the event on.
|
|
;; Is there a more correct way to reconstruct the event?
|
|
(if (and (not have-scrolled)
|
|
(mouse-drag-events-are-point-events-p start-posn end))
|
|
(push (cons (event-basic-type start-event) (cdr start-event))
|
|
unread-command-events))
|
|
;; Now restore the old window.
|
|
(select-window old-selected-window)))
|
|
|
|
|
|
(provide 'mouse-drag)
|
|
|
|
;; arch-tag: e47354ff-82f5-42c4-b3dc-88dd9c04b770
|
|
;;; mouse-drag.el ends here
|