-;;; windows.el --- GNU Emacs window commands aside from those written in C.
+;;; window.el --- GNU Emacs window commands aside from those written in C
-;; Copyright (C) 1985, 1989 Free Software Foundation, Inc.
+;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001
+;; Free Software Foundation, Inc.
+
+;; Maintainer: FSF
+;; Keywords: internal
;; 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,
;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.
+;; 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:
+
+;; Window tree functions.
+
+;;; Code:
+
+(defun one-window-p (&optional nomini all-frames)
+ "Return 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, if you are using a separate minibuffer frame
+and the minibuffer is active and MINIBUF says it counts,
+`walk-windows' includes the windows in the frame from which you
+entered the minibuffer, as well as the minibuffer window.
+
+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.
+If ALL-FRAMES is a frame, it means include windows on that frame.
+Anything else means restrict to the selected 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))
+ (save-selected-window
+ (if (framep all-frames)
+ (select-window (frame-first-window all-frames)))
+ (let* (walk-windows-already-seen
+ (walk-windows-current (selected-window)))
+ (while (progn
+ (setq walk-windows-current
+ (next-window walk-windows-current minibuf all-frames))
+ (not (memq walk-windows-current walk-windows-already-seen)))
+ (setq walk-windows-already-seen
+ (cons walk-windows-current walk-windows-already-seen))
+ (funcall proc walk-windows-current)))))
+
+(defun get-window-with-predicate (predicate &optional minibuf
+ all-frames default)
+ "Return a window satisfying PREDICATE.
+
+This function cycles through all visible windows using `walk-windows',
+calling PREDICATE on each one. PREDICATE is called with a window as
+argument. The first window for which PREDICATE returns a non-nil
+value is returned. If no window satisfies PREDICATE, DEFAULT is
+returned.
+
+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, if you are using a separate minibuffer frame
+and the minibuffer is active and MINIBUF says it counts,
+`walk-windows' includes the windows in the frame from which you
+entered the minibuffer, as well as the minibuffer window.
+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.
+If ALL-FRAMES is a frame, it means include windows on that frame.
+Anything else means restrict to the selected frame."
+ (catch 'found
+ (walk-windows #'(lambda (window)
+ (when (funcall predicate window)
+ (throw 'found window)))
+ minibuf all-frames)
+ default))
+
+(defalias 'some-window 'get-window-with-predicate)
+
+(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."
+ `(let ((save-selected-window-window (selected-window)))
+ (unwind-protect
+ (progn ,@body)
+ (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."
+ "Return the number of visible windows.
+This counts the windows in the selected frame and (if the minibuffer is
+to be counted) its minibuffer frame (if that's not the same frame).
+The optional arg MINIBUF non-nil means count the minibuffer
+even if it is inactive."
(let ((count 0))
- (walk-windows (function (lambda ()
+ (walk-windows (function (lambda (w)
(setq count (+ count 1))))
minibuf)
count))
+(defun window-safely-shrinkable-p (&optional window)
+ "Non-nil if the WINDOW can be shrunk without shrinking other windows.
+If WINDOW is nil or omitted, it defaults to the currently selected window."
+ (save-selected-window
+ (when window (select-window window))
+ (or (and (not (eq window (frame-first-window)))
+ (= (car (window-edges))
+ (car (window-edges (previous-window)))))
+ (= (car (window-edges))
+ (car (window-edges (next-window)))))))
+
(defun balance-windows ()
- "Makes all visible windows the same size (approximately)."
+ "Make 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
+ ;; Don't count the lines that are above the uppermost windows.
+ ;; (These are the menu bar lines, if any.)
+ (mbl (nth 1 (window-edges (frame-first-window (selected-frame))))))
+ ;; 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) mbl) 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 so that both windows keep the original
-value of point. This is often more convenient for editing.
-If nil, split windows to minimize redisplay. This is convenient on
-slow terminals, but point may be moved strangely to accommodate the
-redisplay.")
+(defcustom 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."
+ :type 'boolean
+ :group 'windows)
(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.
-If the variable split-window-keep-point is non-nil, both new windows
+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.
(interactive "P")
(let ((old-w (selected-window))
(old-point (point))
- new-w bottom switch)
- (setq new-w (split-window nil (and arg (prefix-numeric-value arg))))
+ (size (and arg (prefix-numeric-value arg)))
+ (window-full-p nil)
+ new-w bottom switch moved)
+ (and size (< size 0) (setq size (+ (window-height) size)))
+ (setq new-w (split-window nil size))
(or split-window-keep-point
(progn
(save-excursion
(set-buffer (window-buffer))
(goto-char (window-start))
- (vertical-motion (window-height))
+ (setq moved (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)))))))
+ (and (= moved (window-height))
+ (progn
+ (setq window-full-p t)
+ (vertical-motion -1)))
+ (setq bottom (point)))
+ (and window-full-p
+ (<= bottom (point))
+ (set-window-point old-w (1- bottom)))
+ (and window-full-p
+ (<= (window-start new-w) old-point)
+ (progn
+ (set-window-point new-w old-point)
+ (select-window new-w)))))
+ (split-window-save-restore-data new-w old-w)))
+
+;; This is to avoid compiler warnings.
+(defvar view-return-to-alist)
+
+(defun split-window-save-restore-data (new-w old-w)
+ (save-excursion
+ (set-buffer (window-buffer))
+ (if view-mode
+ (let ((old-info (assq old-w view-return-to-alist)))
+ (setq view-return-to-alist
+ (cons (cons new-w (cons (and old-info (car (cdr old-info))) t))
+ view-return-to-alist))))
+ 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.
+The argument includes the width of the window's scroll bar; if there
+are no scroll bars, it includes the width of the divider column
+to the window's right, if any. No arg means split equally."
(interactive "P")
- (split-window nil (and arg (prefix-numeric-value arg)) t))
+ (let ((old-w (selected-window))
+ (size (and arg (prefix-numeric-value arg))))
+ (and size (< size 0)
+ (setq size (+ (window-width) size)))
+ (split-window-save-restore-data (split-window nil size t) old-w)))
+
+\f
+(defun set-window-text-height (window height)
+ "Sets the height in lines of the text display area of WINDOW to HEIGHT.
+This doesn't include the mode-line (or header-line if any) or any
+partial-height lines in the text display area.
+
+If WINDOW is nil, the selected window is used.
+Note that the current implementation of this function cannot always set
+the height exactly, but attempts to be conservative, by allocating more
+lines than are actually needed in the case where some error may be present."
+ (let ((delta (- height (window-text-height window))))
+ (unless (zerop delta)
+ (let ((window-min-height 1))
+ (if (and window (not (eq window (selected-window))))
+ (save-selected-window
+ (select-window window)
+ (enlarge-window delta))
+ (enlarge-window delta))))))
+
+\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 window-buffer-height (window)
+ "Return the height (in screen lines) of the buffer that WINDOW is displaying."
+ (save-excursion
+ (set-buffer (window-buffer window))
+ (goto-char (point-min))
+ (let ((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)))))))
+ (+ 1 (nth 2 (compute-motion (point-min)
+ '(0 . 0)
+ (- (point-max) (if ignore-final-newline 1 0))
+ (cons 0 100000000)
+ (window-width window)
+ nil
+ window))))))
+
+(defun count-screen-lines (&optional beg end count-final-newline window)
+ "Return the number of screen lines in the region.
+The number of screen lines may be different from the number of actual lines,
+due to line breaking, display table, etc.
+
+Optional arguments BEG and END default to `point-min' and `point-max'
+respectively.
+
+If region ends with a newline, ignore it unless optional third argument
+COUNT-FINAL-NEWLINE is non-nil.
+
+The optional fourth argument WINDOW specifies the window used for obtaining
+parameters such as width, horizontal scrolling, and so on. The default is
+to use the selected window's parameters.
+
+Like `vertical-motion', `count-screen-lines' always uses the current buffer,
+regardless of which buffer is displayed in WINDOW. This makes possible to use
+`count-screen-lines' in any buffer, whether or not it is currently displayed
+in some window."
+ (unless beg
+ (setq beg (point-min)))
+ (unless end
+ (setq end (point-max)))
+ (if (= beg end)
+ 0
+ (save-excursion
+ (save-restriction
+ (widen)
+ (narrow-to-region (min beg end)
+ (if (and (not count-final-newline)
+ (= ?\n (char-before (max beg end))))
+ (1- (max beg end))
+ (max beg end)))
+ (goto-char (point-min))
+ (1+ (vertical-motion (buffer-size) window))))))
+
+(defun fit-window-to-buffer (&optional window max-height min-height)
+ "Make WINDOW the right size to display its contents exactly.
+If WINDOW is omitted or nil, it defaults to the selected window.
+If the optional argument MAX-HEIGHT is supplied, it is the maximum height
+ the window is allowed to be, defaulting to the frame height.
+If the optional argument MIN-HEIGHT is supplied, it is the minimum
+ height the window is allowed to be, defaulting to `window-min-height'.
+
+The heights in MAX-HEIGHT and MIN-HEIGHT include the mode-line and/or
+header-line."
+ (interactive)
+
+ (when (null window)
+ (setq window (selected-window)))
+ (when (null max-height)
+ (setq max-height (frame-height (window-frame window))))
+
+ (let* ((buf
+ ;; Buffer that is displayed in WINDOW
+ (window-buffer window))
+ (window-height
+ ;; The current height of WINDOW
+ (window-height window))
+ (desired-height
+ ;; The height necessary to show the buffer displayed by WINDOW
+ ;; (`count-screen-lines' always works on the current buffer).
+ (with-current-buffer buf
+ (+ (count-screen-lines)
+ ;; If the buffer is empty, (count-screen-lines) is
+ ;; zero. But, even in that case, we need one text line
+ ;; for cursor.
+ (if (= (point-min) (point-max))
+ 1 0)
+ ;; For non-minibuffers, count the mode-line, if any
+ (if (and (not (window-minibuffer-p window))
+ mode-line-format)
+ 1 0)
+ ;; Count the header-line, if any
+ (if header-line-format 1 0))))
+ (delta
+ ;; Calculate how much the window height has to change to show
+ ;; desired-height lines, constrained by MIN-HEIGHT and MAX-HEIGHT.
+ (- (max (min desired-height max-height)
+ (or min-height window-min-height))
+ window-height))
+ ;; We do our own height checking, so avoid any restrictions due to
+ ;; window-min-height.
+ (window-min-height 1))
+
+ ;; Don't try to redisplay with the cursor at the end
+ ;; on its own line--that would force a scroll and spoil things.
+ (when (with-current-buffer buf
+ (and (eobp) (bolp) (not (bobp))))
+ (set-window-point window (1- (window-point window))))
+
+ (save-selected-window
+ (select-window window)
+
+ ;; Adjust WINDOW to the nominally correct size (which may actually
+ ;; be slightly off because of variable height text, etc).
+ (unless (zerop delta)
+ (enlarge-window delta))
+
+ ;; Check if the last line is surely fully visible. If not,
+ ;; enlarge the window.
+ (let ((end (with-current-buffer buf
+ (save-excursion
+ (goto-char (point-max))
+ (when (and (bolp) (not (bobp)))
+ ;; Don't include final newline
+ (backward-char 1))
+ (when truncate-lines
+ ;; If line-wrapping is turned off, test the
+ ;; beginning of the last line for visibility
+ ;; instead of the end, as the end of the line
+ ;; could be invisible by virtue of extending past
+ ;; the edge of the window.
+ (forward-line 0))
+ (point)))))
+ (set-window-vscroll window 0)
+ (while (and (< desired-height max-height)
+ (= desired-height (window-height window))
+ (not (pos-visible-in-window-p end window)))
+ (enlarge-window 1)
+ (setq desired-height (1+ desired-height)))))))
+
+(defun shrink-window-if-larger-than-buffer (&optional window)
+ "Shrink the WINDOW to be as small as possible to display its contents.
+If WINDOW is omitted or nil, it defaults to the selected window.
+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 shrinking this window would also shrink another window.
+or if the window is the only window of its frame.
+Return non-nil if the window was shrunk."
+ (interactive)
+ (when (null window)
+ (setq window (selected-window)))
+ (let* ((frame (window-frame window))
+ (mini (frame-parameter frame 'minibuffer))
+ (edges (window-edges window)))
+ (if (and (not (eq window (frame-root-window frame)))
+ (window-safely-shrinkable-p)
+ (pos-visible-in-window-p (point-min) window)
+ (not (eq mini 'only))
+ (or (not mini)
+ (let ((mini-window (minibuffer-window frame)))
+ (or (null mini-window)
+ (not (eq frame (window-frame mini-window)))
+ (< (nth 3 edges)
+ (nth 1 (window-edges mini-window)))
+ (> (nth 1 edges)
+ (frame-parameter frame 'menu-bar-lines))))))
+ (fit-window-to-buffer window (window-height window)))))
+
+(defun kill-buffer-and-window ()
+ "Kill the current buffer and delete the selected window."
+ (interactive)
+ (if (yes-or-no-p (format "Kill buffer `%s'? " (buffer-name)))
+ (let ((buffer (current-buffer)))
+ (delete-window (selected-window))
+ (kill-buffer buffer))
+ (error "Aborted")))
+
+(defun quit-window (&optional kill window)
+ "Quit the current buffer. Bury it, and maybe delete the selected frame.
+\(The frame is deleted if it is contains a dedicated window for the buffer.)
+With a prefix argument, kill the buffer instead.
+
+Noninteractively, if KILL is non-nil, then kill the current buffer,
+otherwise bury it.
+
+If WINDOW is non-nil, it specifies a window; we delete that window,
+and the buffer that is killed or buried is the one in that window."
+ (interactive "P")
+ (let ((buffer (window-buffer window))
+ (frame (window-frame (or window (selected-window))))
+ (window-solitary
+ (save-selected-window
+ (if window
+ (select-window window))
+ (one-window-p t)))
+ window-handled)
+
+ (save-selected-window
+ (if window
+ (select-window window))
+ (or (window-minibuffer-p)
+ (window-dedicated-p (selected-window))
+ (switch-to-buffer (other-buffer))))
+
+ ;; Get rid of the frame, if it has just one dedicated window
+ ;; and other visible frames exist.
+ (and (or (window-minibuffer-p) (window-dedicated-p window))
+ (delq frame (visible-frame-list))
+ window-solitary
+ (if (and (eq default-minibuffer-frame frame)
+ (= 1 (length (minibuffer-frame-list))))
+ (setq window nil)
+ (delete-frame frame)
+ (setq window-handled t)))
+
+ ;; Deal with the buffer.
+ (if kill
+ (kill-buffer buffer)
+ (bury-buffer buffer))
-(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)))
+ ;; Maybe get rid of the window.
+ (and window (not window-handled) (not window-solitary)
+ (delete-window window))))
(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)
+(define-key ctl-x-4-map "0" 'kill-buffer-and-window)
-;;; windows.el ends here
+;;; window.el ends here