-;; GNU Emacs window commands aside from those written in C.
-;; Copyright (C) 1985, 1989 Free Software Foundation, Inc.
+;;; window.el --- GNU Emacs window commands aside from those written in C.
+
+;;; Copyright (C) 1985, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
+
+;; Maintainer: FSF
;; 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 1, or (at your option)
+;; 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,
;; along with GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+;;; Code:
+
+;;;; Window tree functions.
+
+(defun one-window-p (&optional nomini all-frames)
+ "Returns non-nil if the selected window is the only window (in its frame).
+Optional arg NOMINI non-nil means don't count the minibuffer
+even if it is active.
+
+The optional arg ALL-FRAMES t means count windows on all frames.
+If it is `visible', count windows on all visible frames.
+ALL-FRAMES nil or omitted means count only the selected frame,
+plus the minibuffer it uses (which may be on another frame).
+If ALL-FRAMES is neither nil nor t, count only the selected frame."
+ (let ((base-window (selected-window)))
+ (if (and nomini (eq base-window (minibuffer-window)))
+ (setq base-window (next-window base-window)))
+ (eq base-window
+ (next-window base-window (if nomini 'arg) all-frames))))
+
+(defun walk-windows (proc &optional minibuf all-frames)
+ "Cycle through all visible windows, calling PROC for each one.
+PROC is called with a window as argument.
+
+Optional second arg MINIBUF t means count the minibuffer window even
+if not active. MINIBUF nil or omitted means count the minibuffer iff
+it is active. MINIBUF neither t nor nil means not to count the
+minibuffer even if it is active.
+
+Several frames may share a single minibuffer; if the minibuffer
+counts, all windows on all frames that share that minibuffer count
+too. Therefore, when a separate minibuffer frame is active,
+`walk-windows' includes the windows in the frame from which you
+entered the minibuffer, as well as the minibuffer window. But if the
+minibuffer does not count, only windows from WINDOW's frame count.
+
+ALL-FRAMES is the optional third argument.
+ALL-FRAMES nil or omitted means cycle within the frames as specified above.
+ALL-FRAMES = `visible' means include windows on all visible frames.
+ALL-FRAMES = 0 means include windows on all visible and iconified frames.
+ALL-FRAMES = t means include windows on all frames including invisible frames.
+Anything else means restrict to WINDOW's frame."
+ ;; If we start from the minibuffer window, don't fail to come back to it.
+ (if (window-minibuffer-p (selected-window))
+ (setq minibuf t))
+ (let* ((walk-windows-start (selected-window))
+ (walk-windows-current walk-windows-start))
+ (while (progn
+ (setq walk-windows-current
+ (next-window walk-windows-current minibuf all-frames))
+ (funcall proc walk-windows-current)
+ (not (eq walk-windows-current walk-windows-start))))))
+(defun minibuffer-window-active-p (window)
+ "Return t if WINDOW (a minibuffer window) is now active."
+ (eq window (active-minibuffer-window)))
+
+(defmacro save-selected-window (&rest body)
+ "Execute BODY, then select the window that was selected before BODY."
+ (list 'let
+ '((save-selected-window-window (selected-window)))
+ (list 'unwind-protect
+ (cons 'progn body)
+ (list 'select-window 'save-selected-window-window))))
+\f
(defun count-windows (&optional minibuf)
"Returns the number of visible windows.
Optional arg NO-MINI non-nil means don't count the minibuffer
even if it is active."
(let ((count 0))
- (walk-windows (function (lambda ()
+ (walk-windows (function (lambda (w)
(setq count (+ count 1))))
minibuf)
count))
(defun balance-windows ()
- "Makes all visible windows the same size (approximately)."
+ "Makes all visible windows the same height (approximately)."
(interactive)
- (let ((count 0))
- (walk-windows (function (lambda (w)
- (setq count (+ count 1))))
+ (let ((count -1) levels newsizes size)
+ ;; Find all the different vpos's at which windows start,
+ ;; then count them. But ignore levels that differ by only 1.
+ (save-window-excursion
+ (let (tops (prev-top -2))
+ (walk-windows (function (lambda (w)
+ (setq tops (cons (nth 1 (window-edges w))
+ tops))))
+ 'nomini)
+ (setq tops (sort tops '<))
+ (while tops
+ (if (> (car tops) (1+ prev-top))
+ (setq prev-top (car tops)
+ count (1+ count)))
+ (setq levels (cons (cons (car tops) count) levels))
+ (setq tops (cdr tops)))
+ (setq count (1+ count))))
+ ;; Subdivide the frame into that many vertical levels.
+ (setq size (/ (frame-height) count))
+ (walk-windows (function
+ (lambda (w)
+ (select-window w)
+ (let ((newtop (cdr (assq (nth 1 (window-edges))
+ levels)))
+ (newbot (or (cdr (assq (+ (window-height)
+ (nth 1 (window-edges)))
+ levels))
+ count)))
+ (setq newsizes
+ (cons (cons w (* size (- newbot newtop)))
+ newsizes)))))
'nomini)
- (let ((size (/ (screen-height) count)))
- (walk-windows (function (lambda (w)
- (select-window w)
- (enlarge-window (- size (window-height)))))
- 'nomini))))
+ (walk-windows (function (lambda (w)
+ (select-window w)
+ (let ((newsize (cdr (assq w newsizes))))
+ (enlarge-window (- newsize
+ (window-height))))))
+ 'nomini)))
+\f
+;;; I think this should be the default; I think people will prefer it--rms.
+(defvar split-window-keep-point t
+ "*If non-nil, split windows keeps the original point in both children.
+This is often more convenient for editing.
+If nil, adjust point in each of the two windows to minimize redisplay.
+This is convenient on slow terminals, but point can move strangely.")
(defun split-window-vertically (&optional arg)
"Split current window into two windows, one above the other.
The uppermost window gets ARG lines and the other gets the rest.
+Negative arg means select the size of the lowermost window instead.
With no argument, split equally or close to it.
Both windows display the same buffer now current.
-The new selected window is the one that the current value of point
-appears in.
-The value of point can change if the text around point
-is hidden by the new mode line."
+If the variable split-window-keep-point is non-nil, both new windows
+will get the same value of point as the current window. This is often
+more convenient for editing.
+
+Otherwise, we chose window starts so as to minimize the amount of
+redisplay; this is convenient on slow terminals. The new selected
+window is the one that the current value of point appears in. The
+value of point can change if the text around point is hidden by the
+new mode line."
(interactive "P")
(let ((old-w (selected-window))
(old-point (point))
+ (size (and arg (prefix-numeric-value arg)))
new-w bottom switch)
- (setq new-w (split-window nil (and arg (prefix-numeric-value arg))))
- (save-excursion
- (set-buffer (window-buffer))
- (goto-char (window-start))
- (vertical-motion (window-height))
- (set-window-start new-w (point))
- (if (> (point) (window-point new-w))
- (set-window-point new-w (point)))
- (vertical-motion -1)
- (setq bottom (point)))
- (if (<= bottom (point))
- (set-window-point old-w (1- bottom)))
- (if (< (window-start new-w) old-point)
+ (and size (< size 0) (setq size (+ (window-height) size)))
+ (setq new-w (split-window nil size))
+ (or split-window-keep-point
(progn
- (set-window-point new-w old-point)
- (select-window new-w)))))
+ (save-excursion
+ (set-buffer (window-buffer))
+ (goto-char (window-start))
+ (vertical-motion (window-height))
+ (set-window-start new-w (point))
+ (if (> (point) (window-point new-w))
+ (set-window-point new-w (point)))
+ (vertical-motion -1)
+ (setq bottom (point)))
+ (if (<= bottom (point))
+ (set-window-point old-w (1- bottom)))
+ (if (< (window-start new-w) old-point)
+ (progn
+ (set-window-point new-w old-point)
+ (select-window new-w)))))
+ new-w))
(defun split-window-horizontally (&optional arg)
"Split current window into two windows side by side.
-This window becomes the leftmost of the two, and gets
-ARG columns. No arg means split equally."
+This window becomes the leftmost of the two, and gets ARG columns.
+Negative arg means select the size of the rightmost window instead.
+No arg means split equally."
(interactive "P")
- (split-window nil (and arg (prefix-numeric-value arg)) t))
-
+ (let ((size (and arg (prefix-numeric-value arg))))
+ (and size (< size 0)
+ (setq size (+ (window-width) size)))
+ (split-window nil size t)))
+\f
(defun enlarge-window-horizontally (arg)
"Make current window ARG columns wider."
(interactive "p")
(interactive "p")
(shrink-window arg t))
-(defun window-config-to-register (name)
- "Save the current window configuration in register REG (a letter).
-It can be later retrieved using \\[M-x register-to-window-config]."
- (interactive "cSave window configuration in register: ")
- (set-register name (current-window-configuration)))
-
-(defun register-to-window-config (name)
- "Restore (make current) the window configuration in register REG (a letter).
-Use with a register previously set with \\[window-config-to-register]."
- (interactive "cRestore window configuration from register: ")
- (set-window-configuration (get-register name)))
-
+(defun shrink-window-if-larger-than-buffer (&optional window)
+ "Shrink the WINDOW to be as small as possible to display its contents.
+Do not shrink to less than `window-min-height' lines.
+Do nothing if the buffer contains more lines than the present window height,
+or if some of the window's contents are scrolled out of view,
+or if the window is not the full width of the frame,
+or if the window is the only window of its frame."
+ (interactive)
+ (or window (setq window (selected-window)))
+ (save-excursion
+ (set-buffer (window-buffer window))
+ (let* ((w (selected-window)) ;save-window-excursion can't win
+ (buffer-file-name buffer-file-name)
+ (p (point))
+ (n 0)
+ (ignore-final-newline
+ ;; If buffer ends with a newline, ignore it when counting height
+ ;; unless point is after it.
+ (and (not (eobp))
+ (eq ?\n (char-after (1- (point-max))))))
+ (buffer-read-only nil)
+ (modified (buffer-modified-p))
+ (buffer (current-buffer))
+ (params (frame-parameters (window-frame window)))
+ (mini (cdr (assq 'minibuffer params)))
+ (edges (window-edges (selected-window))))
+ (if (and (< 1 (let ((frame (selected-frame)))
+ (select-frame (window-frame window))
+ (unwind-protect
+ (count-windows)
+ (select-frame frame))))
+ (= (window-width window) (frame-width (window-frame window)))
+ (pos-visible-in-window-p (point-min) window)
+ (not (eq mini 'only))
+ (or (not mini)
+ (< (nth 3 edges)
+ (nth 1 (window-edges mini)))
+ (> (nth 1 edges)
+ (cdr (assq 'menu-bar-lines params)))))
+ (unwind-protect
+ (progn
+ (select-window (or window w))
+ (goto-char (point-min))
+ (while (pos-visible-in-window-p
+ (- (point-max)
+ (if ignore-final-newline 1 0)))
+ ;; defeat file locking... don't try this at home, kids!
+ (setq buffer-file-name nil)
+ (insert ?\n) (setq n (1+ n)))
+ (if (> n 0)
+ (shrink-window (min (1- n)
+ (- (window-height)
+ window-min-height)))))
+ (delete-region (point-min) (point))
+ (set-buffer-modified-p modified)
+ (goto-char p)
+ (select-window w)
+ ;; Make sure we unbind buffer-read-only
+ ;; with the proper current buffer.
+ (set-buffer buffer))))))
+
(define-key ctl-x-map "2" 'split-window-vertically)
-(define-key ctl-x-map "5" 'split-window-horizontally)
-(define-key ctl-x-map "6" 'window-config-to-register)
-(define-key ctl-x-map "7" 'register-to-window-config)
+(define-key ctl-x-map "3" 'split-window-horizontally)
(define-key ctl-x-map "}" 'enlarge-window-horizontally)
(define-key ctl-x-map "{" 'shrink-window-horizontally)
+(define-key ctl-x-map "-" 'shrink-window-if-larger-than-buffer)
+(define-key ctl-x-map "+" 'balance-windows)
+
+;;; windows.el ends here