1 ;;; window.el --- GNU Emacs window commands aside from those written in C.
3 ;; Copyright (C) 1985, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software; you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation; either version 2, or (at your option)
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs; see the file COPYING. If not, write to the
21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
22 ;; Boston, MA 02111-1307, USA.
26 ;;;; Window tree functions.
28 (defun one-window-p (&optional nomini all-frames)
29 "Returns non-nil if the selected window is the only window (in its frame).
30 Optional arg NOMINI non-nil means don't count the minibuffer
33 The optional arg ALL-FRAMES t means count windows on all frames.
34 If it is `visible', count windows on all visible frames.
35 ALL-FRAMES nil or omitted means count only the selected frame,
36 plus the minibuffer it uses (which may be on another frame).
37 If ALL-FRAMES is neither nil nor t, count only the selected frame."
38 (let ((base-window (selected-window)))
39 (if (and nomini (eq base-window (minibuffer-window)))
40 (setq base-window (next-window base-window)))
42 (next-window base-window (if nomini 'arg) all-frames))))
44 (defun walk-windows (proc &optional minibuf all-frames)
45 "Cycle through all visible windows, calling PROC for each one.
46 PROC is called with a window as argument.
48 Optional second arg MINIBUF t means count the minibuffer window even
49 if not active. MINIBUF nil or omitted means count the minibuffer iff
50 it is active. MINIBUF neither t nor nil means not to count the
51 minibuffer even if it is active.
53 Several frames may share a single minibuffer; if the minibuffer
54 counts, all windows on all frames that share that minibuffer count
55 too. Therefore, if you are using a separate minibuffer frame
56 and the minibuffer is active and MINIBUF says it counts,
57 `walk-windows' includes the windows in the frame from which you
58 entered the minibuffer, as well as the minibuffer window.
60 ALL-FRAMES is the optional third argument.
61 ALL-FRAMES nil or omitted means cycle within the frames as specified above.
62 ALL-FRAMES = `visible' means include windows on all visible frames.
63 ALL-FRAMES = 0 means include windows on all visible and iconified frames.
64 ALL-FRAMES = t means include windows on all frames including invisible frames.
65 Anything else means restrict to the selected frame."
66 ;; If we start from the minibuffer window, don't fail to come back to it.
67 (if (window-minibuffer-p (selected-window))
69 (let* ((walk-windows-start (selected-window))
70 (walk-windows-current walk-windows-start))
72 (setq walk-windows-current
73 (next-window walk-windows-current minibuf all-frames))
74 (funcall proc walk-windows-current)
75 (not (eq walk-windows-current walk-windows-start))))))
77 (defun minibuffer-window-active-p (window)
78 "Return t if WINDOW (a minibuffer window) is now active."
79 (eq window (active-minibuffer-window)))
81 (defmacro save-selected-window (&rest body)
82 "Execute BODY, then select the window that was selected before BODY."
84 '((save-selected-window-window (selected-window)))
87 (list 'select-window 'save-selected-window-window))))
89 (defun count-windows (&optional minibuf)
90 "Returns the number of visible windows.
91 Optional arg MINIBUF non-nil means count the minibuffer
92 even if it is inactive."
94 (walk-windows (function (lambda (w)
95 (setq count (+ count 1))))
99 (defun balance-windows ()
100 "Makes all visible windows the same height (approximately)."
102 (let ((count -1) levels newsizes size
103 ;; Don't count the lines that are above the uppermost windows.
104 ;; (These are the menu bar lines, if any.)
105 (mbl (nth 1 (window-edges (frame-first-window (selected-frame))))))
106 ;; Find all the different vpos's at which windows start,
107 ;; then count them. But ignore levels that differ by only 1.
108 (save-window-excursion
109 (let (tops (prev-top -2))
110 (walk-windows (function (lambda (w)
111 (setq tops (cons (nth 1 (window-edges w))
114 (setq tops (sort tops '<))
116 (if (> (car tops) (1+ prev-top))
117 (setq prev-top (car tops)
119 (setq levels (cons (cons (car tops) count) levels))
120 (setq tops (cdr tops)))
121 (setq count (1+ count))))
122 ;; Subdivide the frame into that many vertical levels.
123 (setq size (/ (- (frame-height) mbl) count))
124 (walk-windows (function
127 (let ((newtop (cdr (assq (nth 1 (window-edges))
129 (newbot (or (cdr (assq (+ (window-height)
130 (nth 1 (window-edges)))
134 (cons (cons w (* size (- newbot newtop)))
137 (walk-windows (function (lambda (w)
139 (let ((newsize (cdr (assq w newsizes))))
140 (enlarge-window (- newsize
144 ;;; I think this should be the default; I think people will prefer it--rms.
145 (defcustom split-window-keep-point t
146 "*If non-nil, split windows keeps the original point in both children.
147 This is often more convenient for editing.
148 If nil, adjust point in each of the two windows to minimize redisplay.
149 This is convenient on slow terminals, but point can move strangely."
153 (defun split-window-vertically (&optional arg)
154 "Split current window into two windows, one above the other.
155 The uppermost window gets ARG lines and the other gets the rest.
156 Negative arg means select the size of the lowermost window instead.
157 With no argument, split equally or close to it.
158 Both windows display the same buffer now current.
160 If the variable split-window-keep-point is non-nil, both new windows
161 will get the same value of point as the current window. This is often
162 more convenient for editing.
164 Otherwise, we chose window starts so as to minimize the amount of
165 redisplay; this is convenient on slow terminals. The new selected
166 window is the one that the current value of point appears in. The
167 value of point can change if the text around point is hidden by the
170 (let ((old-w (selected-window))
172 (size (and arg (prefix-numeric-value arg)))
174 new-w bottom switch moved)
175 (and size (< size 0) (setq size (+ (window-height) size)))
176 (setq new-w (split-window nil size))
177 (or split-window-keep-point
180 (set-buffer (window-buffer))
181 (goto-char (window-start))
182 (setq moved (vertical-motion (window-height)))
183 (set-window-start new-w (point))
184 (if (> (point) (window-point new-w))
185 (set-window-point new-w (point)))
186 (and (= moved (window-height))
188 (setq window-full-p t)
189 (vertical-motion -1)))
190 (setq bottom (point)))
193 (set-window-point old-w (1- bottom)))
195 (<= (window-start new-w) old-point)
197 (set-window-point new-w old-point)
198 (select-window new-w)))))
199 (split-window-save-restore-data new-w old-w)))
201 ;; This is to avoid compiler warnings.
202 (defvar view-return-to-alist)
204 (defun split-window-save-restore-data (new-w old-w)
206 (set-buffer (window-buffer))
208 (let ((old-info (assq old-w view-return-to-alist)))
209 (setq view-return-to-alist
210 (cons (cons new-w (cons (and old-info (car (cdr old-info))) t))
211 view-return-to-alist))))
214 (defun split-window-horizontally (&optional arg)
215 "Split current window into two windows side by side.
216 This window becomes the leftmost of the two, and gets ARG columns.
217 Negative arg means select the size of the rightmost window instead.
218 No arg means split equally."
220 (let ((old-w (selected-window))
221 (size (and arg (prefix-numeric-value arg))))
223 (setq size (+ (window-width) size)))
224 (split-window-save-restore-data (split-window nil size t) old-w)))
226 (defun enlarge-window-horizontally (arg)
227 "Make current window ARG columns wider."
229 (enlarge-window arg t))
231 (defun shrink-window-horizontally (arg)
232 "Make current window ARG columns narrower."
234 (shrink-window arg t))
236 (defun shrink-window-if-larger-than-buffer (&optional window)
237 "Shrink the WINDOW to be as small as possible to display its contents.
238 Do not shrink to less than `window-min-height' lines.
239 Do nothing if the buffer contains more lines than the present window height,
240 or if some of the window's contents are scrolled out of view,
241 or if the window is not the full width of the frame,
242 or if the window is the only window of its frame."
244 (or window (setq window (selected-window)))
245 (let* ((ignore-final-newline
246 ;; If buffer ends with a newline, ignore it when counting height
247 ;; unless point is after it.
249 (eq ?\n (char-after (1- (point-max))))))
250 (params (frame-parameters (window-frame window)))
251 (mini (cdr (assq 'minibuffer params)))
252 (edges (window-edges (selected-window)))
254 (if (and (< 1 (save-selected-window
255 (select-window window)
257 (= (window-width window) (frame-width (window-frame window)))
258 (pos-visible-in-window-p (point-min) window)
259 (not (eq mini 'only))
262 (nth 1 (window-edges mini)))
264 (cdr (assq 'menu-bar-lines params)))))
265 (save-selected-window
266 (select-window window)
269 (set-buffer (window-buffer window))
270 (goto-char (point-min))
272 (compute-motion (point-min) '(0 . 0)
274 (if ignore-final-newline 1 0))
275 (cons 0 (window-height))
278 ;; Get number of screen lines that the text needs.
279 (setq text-height (+ 1 (nth 2 result)))
280 ;; Shrink down to that, or as far as we can go.
281 (if (> (window-height) (1+ text-height))
282 (shrink-window (- (window-height)
283 (max (1+ text-height) window-min-height))))))))))
285 (defun kill-buffer-and-window ()
286 "Kill the current buffer and delete the selected window."
288 (if (yes-or-no-p (format "Kill buffer `%s'? " (buffer-name)))
289 (let ((buffer (current-buffer)))
290 (delete-window (selected-window))
291 (kill-buffer buffer))
294 (defun quit-window (&optional kill window)
295 "Quit the current buffer. Bury it, and maybe delete the selected frame.
296 \(The frame is deleted if it is contains a dedicated window for the buffer.)
297 With a prefix argument, kill the buffer instead.
299 Noninteractively, if KILL is non-nil, then kill the current buffer,
302 If WINDOW is non-nil, it specifies a window; we delete that window,
303 and the buffer that is killed or buried is the one in that window."
305 (let ((buffer (window-buffer window))
306 (frame (if window (window-frame window) (selected-window)))
308 (save-selected-window
310 (select-window window))
314 (save-selected-window
316 (select-window window))
317 (switch-to-buffer (other-buffer)))
319 ;; Get rid of the frame, if it has just one dedicated window
320 ;; and other visible frames exist.
321 (and (window-dedicated-p window)
322 (delq frame (visible-frame-list))
324 (if (and (eq default-minibuffer-frame frame)
325 (= 1 (length (minibuffer-frame-list))))
328 (setq window-handled t)))
330 ;; Deal with the buffer.
333 (bury-buffer buffer))
335 ;; Maybe get rid of the window.
336 (and window (not window-handled) (not window-solitary)
337 (delete-window window))))
339 (define-key ctl-x-map "2" 'split-window-vertically)
340 (define-key ctl-x-map "3" 'split-window-horizontally)
341 (define-key ctl-x-map "}" 'enlarge-window-horizontally)
342 (define-key ctl-x-map "{" 'shrink-window-horizontally)
343 (define-key ctl-x-map "-" 'shrink-window-if-larger-than-buffer)
344 (define-key ctl-x-map "+" 'balance-windows)
345 (define-key ctl-x-4-map "0" 'kill-buffer-and-window)
347 ;;; windows.el ends here