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mirror of https://git.savannah.gnu.org/git/emacs.git synced 2024-11-23 07:19:15 +00:00
emacs/lisp/mldrag.el
Richard M. Stallman 9e5d67df40 (mldrag-drag-vertical-line): Fix criterion
for the error for trying to move a scroll bar at the frame edge.
1998-02-02 05:42:02 +00:00

241 lines
8.8 KiB
EmacsLisp

;;; mldrag.el --- mode line and vertical line dragging to resize windows
;; Copyright (C) 1994 Free Software Foundation, Inc.
;; Author: Kyle E. Jones <kyle@wonderworks.com>
;; 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 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.
;; 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:
;; This package lets you drag the modeline, vertical bar and
;; scrollbar to resize windows. Suggested bindings are:
;;
;; (global-set-key [mode-line down-mouse-1] 'mldrag-drag-mode-line)
;; (global-set-key [vertical-line down-mouse-1] 'mldrag-drag-vertical-line)
;; (global-set-key [vertical-scroll-bar S-down-mouse-1]
;; 'mldrag-drag-vertical-line)
;;
;; Put the bindings and (require 'mldrag) in your .emacs file.
;;; Code:
(provide 'mldrag)
(defun mldrag-drag-mode-line (start-event)
"Change the height of the current window with the mouse.
This command should be bound to a down-mouse- event, and is most
usefully bound with the `mode-line' prefix. Holding down a mouse
button and moving the mouse up and down will make the clicked-on
window taller or shorter."
(interactive "e")
(let ((done nil)
(echo-keystrokes 0)
(start-event-frame (window-frame (car (car (cdr start-event)))))
(start-event-window (car (car (cdr start-event))))
(start-nwindows (count-windows t))
(old-selected-window (selected-window))
should-enlarge-minibuffer
event mouse minibuffer y top bot edges wconfig params growth)
(setq params (frame-parameters))
(if (and (not (setq minibuffer (cdr (assq 'minibuffer params))))
(one-window-p t))
(error "Attempt to resize sole window"))
(unwind-protect
(track-mouse
(progn
;; enlarge-window only works on the selected window, so
;; we must select the window where the start event originated.
;; unwind-protect will restore the old selected window later.
(select-window start-event-window)
;; if this is the bottommost ordinary window, then to
;; move its modeline the minibuffer must be enlarged.
(setq should-enlarge-minibuffer
(and minibuffer
(not (one-window-p t))
(= (nth 1 (window-edges minibuffer))
(nth 3 (window-edges)))))
;; loop reading events and sampling the position of
;; the mouse.
(while (not done)
(setq event (read-event)
mouse (mouse-position))
;; do nothing if
;; - there is a switch-frame event.
;; - the mouse isn't in the frame that we started in
;; - the mouse isn't in any Emacs frame
;; drag if
;; - there is a mouse-movement event
;; - there is a scroll-bar-movement event
;; (same as mouse movement for our purposes)
;; quit if
;; - there is a keyboard event or some other unknown event
;; unknown event.
(cond ((integerp event)
(setq done t))
((eq (car event) 'switch-frame)
nil)
((not (memq (car event)
'(mouse-movement scroll-bar-movement)))
(setq done t))
((not (eq (car mouse) start-event-frame))
nil)
((null (car (cdr mouse)))
nil)
(t
(setq y (cdr (cdr mouse))
edges (window-edges)
top (nth 1 edges)
bot (nth 3 edges))
;; scale back a move that would make the
;; window too short.
(cond ((< (- y top -1) window-min-height)
(setq y (+ top window-min-height -1))))
;; compute size change needed
(setq growth (- y bot -1)
wconfig (current-window-configuration))
;; grow/shrink minibuffer?
(if should-enlarge-minibuffer
(progn
;; yes. briefly select minibuffer so
;; enlarge-window will affect the
;; correct window.
(select-window minibuffer)
;; scale back shrinkage if it would
;; make the minibuffer less than 1
;; line tall.
(if (and (> growth 0)
(< (- (window-height minibuffer)
growth)
1))
(setq growth (1- (window-height minibuffer))))
(enlarge-window (- growth))
(select-window start-event-window))
;; no. grow/shrink the selected window
(enlarge-window growth))
;; if this window's growth caused another
;; window to be deleted because it was too
;; short, rescind the change.
;;
;; if size change caused space to be stolen
;; from a window above this one, rescind the
;; change, but only if we didn't grow/srhink
;; the minibuffer. minibuffer size changes
;; can cause all windows to shrink... no way
;; around it.
(if (or (/= start-nwindows (count-windows t))
(and (not should-enlarge-minibuffer)
(/= top (nth 1 (window-edges)))))
(set-window-configuration wconfig)))))))
;; restore the old selected window
(select-window old-selected-window))))
(defun mldrag-drag-vertical-line (start-event)
"Change the width of the current window with the mouse.
This command should be bound to a down-mouse- event, and is most
usefully bound with the `vertical-line' or the `vertical-scroll-bar'
prefix. Holding down a mouse button and moving the mouse left and
right will make the clicked-on window thinner or wider."
(interactive "e")
(let* ((done nil)
(echo-keystrokes 0)
(start-event-frame (window-frame (car (car (cdr start-event)))))
(scroll-bar-left
(eq (cdr (assq 'vertical-scroll-bars (frame-parameters))) 'left))
(start-event-window (car (car (cdr start-event))))
(start-nwindows (count-windows t))
(old-selected-window (selected-window))
event mouse x left right edges wconfig growth)
(if (one-window-p t)
(error "Attempt to resize sole ordinary window"))
(if scroll-bar-left
(when (= (nth 0 (window-edges start-event-window)) 0)
(error "Attempt to drag leftmost scrollbar"))
(when (>= (nth 2 (window-edges start-event-window))
(frame-width start-event-frame))
(error "Attempt to drag rightmost scrollbar")))
(unwind-protect
(track-mouse
(progn
;; enlarge-window only works on the selected window, so
;; we must select the window where the start event originated.
;; unwind-protect will restore the old selected window later.
(select-window start-event-window)
;; loop reading events and sampling the position of
;; the mouse.
(while (not done)
(setq event (read-event)
mouse (mouse-position))
;; do nothing if
;; - there is a switch-frame event.
;; - the mouse isn't in the frame that we started in
;; - the mouse isn't in any Emacs frame
;; drag if
;; - there is a mouse-movement event
;; - there is a scroll-bar-movement event
;; (same as mouse movement for our purposes)
;; quit if
;; - there is a keyboard event or some other unknown event
;; unknown event.
(cond ((integerp event)
(setq done t))
((eq (car event) 'switch-frame)
nil)
((not (memq (car event)
'(mouse-movement scroll-bar-movement)))
(setq done t))
((not (eq (car mouse) start-event-frame))
nil)
((null (car (cdr mouse)))
nil)
(t
(setq x (car (cdr mouse))
edges (window-edges)
left (nth 0 edges)
right (nth 2 edges))
;; scale back a move that would make the
;; window too thin.
(if scroll-bar-left
(cond ((< (- right x) window-min-width)
(setq x (- right window-min-width))))
(cond ((< (- x left -1) window-min-width)
(setq x (+ left window-min-width -1)))))
;; compute size change needed
(setq growth (if scroll-bar-left
(- left x)
(- x right -1))
wconfig (current-window-configuration))
(enlarge-window growth t)
;; if this window's growth caused another
;; window to be deleted because it was too
;; thin, rescind the change.
;;
;; if size change caused space to be stolen
;; from a window to the left of this one,
;; rescind the change.
(if (or (/= start-nwindows (count-windows t))
(if scroll-bar-left
(/= right (nth 2 (window-edges)))
(/= left (nth 0 (window-edges)))))
(set-window-configuration wconfig)))))))
;; restore the old selected window
(select-window old-selected-window))))
;; mldrag.el ends here