;;; mouse-drag.el --- use mouse-2 to do a new style of scrolling
-;; Copyright (C) 1996, 1997 Free Software Foundation, Inc.
+;; Copyright (C) 1996, 1997, 2001 Free Software Foundation, Inc.
;; Author: John Heidemann <johnh@ISI.EDU>
;; Keywords: mouse
(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."
- (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."
Basically, we check for existing horizontal scrolling."
(or truncate-lines
(> (window-hscroll (selected-window)) 0)
- (< (window-width) (screen-width))
+ (< (window-width) (frame-width))
(and
mouse-drag-electric-col-scrolling
(save-excursion ;; on a long line?
(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
+ have-scrolled
window-last-row
col mouse-col-delta window-last-col
(scroll-col-delta 0)
(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)))
(defun mouse-drag-drag (start-event)
"\"Drag\" the page according to a mouse drag.
(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
+ have-scrolled
window-last-row
col mouse-col-delta window-last-col
(scroll-col-delta 0)
(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)