summaryrefslogtreecommitdiff
path: root/lisp/mldrag.el
blob: 45a10c2e18c469cb4982314636d003b1b300992c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
;;; 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)))))
	(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 (= (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.
		     (cond ((< (- x left -1) window-min-width)
			    (setq x (+ left window-min-width -1))))
		     ;; compute size change needed
		     (setq growth (- 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))
			     (/= left (nth 0 (window-edges))))
			 (set-window-configuration wconfig)))))))
      ;; restore the old selected window
      (select-window old-selected-window))))

;; mldrag.el ends here