-;;; mouse-drag.el
-;;; Copyright (C) 1996 Free Software Foundation, Inc.
+;;; mouse-drag.el --- use mouse-2 to do a new style of scrolling
-;;; Author: John Heidemann <johnh@ISI.EDU>
-;;; Keywords: mouse
+;; Copyright (C) 1996-1997, 2001-2013 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
+;; 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.
+;; 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
;; 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, Inc., 59 Temple Place - Suite 330,
-;; Boston, MA 02111-1307, USA.
+;; 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:
-;;; (require 'mouse-drag)
-;;; -and 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]
-;;;
-;;;
-;;; 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
-;;;
-;;;
-;;; Old changes, for reference:
-;;;
-;;; What's new with mouse-extras 2.21?
-;;;
-;;; - support for emacs-19.{29,30}
-;;; - point now stays on the visible screen during horizontal scrolling
-;;; (bug identified and fix suggested by Tom Wurgler <twurgler@goodyear.com>)
-;;; - better work-around for lost-mouse-events bug (supports double/triple
-;;; clicks), see \\[mouse-extras-work-around-drag-bug] for details.
-;;; - work-around for lost-mouse-events bug now is OFF by default;
-;;; enable it if you have problems
-;;;
-
-
-\f
+;; 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 init 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:
;;
;;
(defun mouse-drag-safe-scroll (row-delta &optional col-delta)
- "* Scroll down ROW-DELTA lines and right COL-DELTA, ignoring buffer edge errors.
+ "Scroll down ROW-DELTA lines and right COL-DELTA, ignoring buffer edge errors.
Keep the cursor on the screen as needed."
- (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)))))))
+ (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."
+ "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\"."
+ "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
+ ;; ;; 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."
+ "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)
- (< (window-width) (screen-width))))
+ (not (window-full-width-p))
+ (and
+ mouse-drag-electric-col-scrolling
+ (save-excursion ;; on a long line?
+ (let
+ ((beg (line-beginning-position))
+ (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.
+ "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-with-scroll-bar
- [-16 -8 -4 -2 -1 0 0 0 1 2 4 8 16])
-(defconst mouse-throw-magnifier-with-mouse-movement
- [ 16 8 4 2 1 0 0 0 -1 -2 -4 -8 -16])
(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.
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
+assume that the user didn't want to scroll 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\"
(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 point-event-p old-binding
- window-last-row
- col mouse-col-delta window-last-col
+ event end row scroll-delta
+ have-scrolled
+ col
(scroll-col-delta 0)
- adjusted-mouse-col-delta
;; be conservative about allowing horizontal scrolling
(col-scrolling-p (mouse-drag-should-do-col-scrolling)))
(select-window start-window)
col (car (posn-col-row end)))
(or (mouse-movement-p event)
(eq (car-safe event) 'switch-frame)))
- (if (eq start-window (posn-window end))
- (progn
- (setq mouse-delta (- start-row row)
- adjusted-mouse-delta
- (- (cond
- ((<= mouse-delta mouse-throw-magnifier-min)
- mouse-throw-magnifier-min)
- ((>= mouse-delta mouse-throw-magnifier-max)
- mouse-throw-magnifier-max)
- (t mouse-delta))
- mouse-throw-magnifier-min)
- scroll-delta (aref (if mouse-throw-with-scroll-bar
- mouse-throw-magnifier-with-scroll-bar
- mouse-throw-magnifier-with-mouse-movement)
- adjusted-mouse-delta))
- (if col-scrolling-p
- (setq mouse-col-delta (- start-col col)
- adjusted-mouse-col-delta
- (- (cond
- ((<= mouse-col-delta mouse-throw-magnifier-min)
- mouse-throw-magnifier-min)
- ((>= mouse-col-delta mouse-throw-magnifier-max)
- mouse-throw-magnifier-max)
- (t mouse-col-delta))
- mouse-throw-magnifier-min)
- scroll-col-delta (aref (if mouse-throw-with-scroll-bar
- mouse-throw-magnifier-with-scroll-bar
- mouse-throw-magnifier-with-mouse-movement)
- adjusted-mouse-col-delta)))))
+ (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
(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.
- ;; Note: We must determine the pass-through event before restoring
- ;; the window, but invoke it after. Sigh.
+ ;; 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))
- (setq point-event-p t
- old-binding (key-binding
- (vector (event-basic-type start-event)))))
+ (push (cons (event-basic-type start-event) (cdr start-event))
+ unread-command-events))
;; Now restore the old window.
- (select-window old-selected-window)
- ;; For clicks, call the old function.
- (if point-event-p
- (call-interactively old-binding))))
+ (select-window old-selected-window)))
+;;;###autoload
(defun mouse-drag-drag (start-event)
"\"Drag\" the page according to a mouse drag.
(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 point-event-p old-binding
+ event end row scroll-delta
+ have-scrolled
window-last-row
- col mouse-col-delta window-last-col
+ col window-last-col
(scroll-col-delta 0)
;; be conservative about allowing horizontal scrolling
(col-scrolling-p (mouse-drag-should-do-col-scrolling)))
(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.
- ;; Note: We must determine the pass-through event before restoring
- ;; the window, but invoke it after. Sigh.
+ ;; 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))
- (setq point-event-p t
- old-binding (key-binding
- (vector (event-basic-type start-event)))))
+ (push (cons (event-basic-type start-event) (cdr start-event))
+ unread-command-events))
;; Now restore the old window.
- (select-window old-selected-window)
- ;; For clicks, call the old function.
- (if point-event-p
- (call-interactively old-binding))))
+ (select-window old-selected-window)))
+
(provide 'mouse-drag)