Fix EOLs broken with last commit.

1 files changed, 1674 insertions, 1674 deletions

diff --git a/lisp/window.el b/lisp/window.el
index 081fb12aab2..295f528ecc2 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -1,1674 +1,1674 @@
-;;; window.el --- GNU Emacs window commands aside from those written in C

-

-;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001, 2002,

-;;   2003, 2004, 2005, 2006, 2007, 2008 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.

-

-;;; Commentary:

-

-;; Window tree functions.

-

-;;; Code:

-

-(eval-when-compile (require 'cl))

-

-(defvar window-size-fixed nil

- "*Non-nil in a buffer means windows displaying the buffer are fixed-size.

-If the value is `height', then only the window's height is fixed.

-If the value is `width', then only the window's width is fixed.

-Any other non-nil value fixes both the width and the height.

-Emacs won't change the size of any window displaying that buffer,

-unless you explicitly change the size, or Emacs has no other choice.")

-(make-variable-buffer-local 'window-size-fixed)

-

-(defmacro save-selected-window (&rest body)

-  "Execute BODY, then select the previously selected window.

-The value returned is the value of the last form in BODY.

-

-This macro saves and restores the selected window, as well as the

-selected window in each frame.  If the previously selected window

-is no longer live, then whatever window is selected at the end of

-BODY remains selected.  If the previously selected window of some

-frame is no longer live at the end of BODY, that frame's selected

-window is left alone.

-

-This macro saves and restores the current buffer, since otherwise

-its normal operation could make a different buffer current.  The

-order of recently selected windows and the buffer list ordering

-are not altered by this macro (unless they are altered in BODY)."

-  `(let ((save-selected-window-window (selected-window))

-         ;; It is necessary to save all of these, because calling

-         ;; select-window changes frame-selected-window for whatever

-         ;; frame that window is in.

-         (save-selected-window-alist

-          (mapcar (lambda (frame) (cons frame (frame-selected-window frame)))

-                  (frame-list))))

-     (save-current-buffer

-       (unwind-protect

-           (progn ,@body)

-         (dolist (elt save-selected-window-alist)

-           (and (frame-live-p (car elt))

-                (window-live-p (cdr elt))

-                (set-frame-selected-window (car elt) (cdr elt) 'norecord)))

-         (when (window-live-p save-selected-window-window)

-           (select-window save-selected-window-window 'norecord))))))

-

-(defun window-body-height (&optional window)

-  "Return number of lines in WINDOW available for actual buffer text.

-WINDOW defaults to the selected window.

-

-The return value does not include the mode line or the header

-line, if any.  If a line at the bottom of the window is only

-partially visible, that line is included in the return value.  If

-you do not want to include a partially visible bottom line in the

-return value, use `window-text-height' instead."

-  (or window (setq window (selected-window)))

-  (if (window-minibuffer-p window)

-      (window-height window)

-    (with-current-buffer (window-buffer window)

-      (max 1 (- (window-height window)

-                (if mode-line-format 1 0)

-                (if header-line-format 1 0))))))

-

-(defun one-window-p (&optional nomini all-frames)

-  "Return non-nil if the selected window is the only window.

-Optional arg NOMINI non-nil means don't count the minibuffer

-even if it is active.  Otherwise, the minibuffer is counted

-when 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).

-ALL-FRAMES 0 means count all windows in all visible or iconified frames.

-If ALL-FRAMES is anything else, 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 window-current-scroll-bars (&optional window)

-  "Return the current scroll bar settings for WINDOW.

-WINDOW defaults to the selected window.

-

-The return value is a cons cell (VERTICAL . HORIZONTAL) where

-VERTICAL specifies the current location of the vertical scroll

-bars (`left', `right', or nil), and HORIZONTAL specifies the

-current location of the horizontal scroll bars (`top', `bottom',

-or nil).

-

-Unlike `window-scroll-bars', this function reports the scroll bar

-type actually used, once frame defaults and `scroll-bar-mode' are

-taken into account."

-  (let ((vert (nth 2 (window-scroll-bars window)))

-        (hor nil))

-    (when (or (eq vert t) (eq hor t))

-      (let ((fcsb (frame-current-scroll-bars

-                   (window-frame (or window (selected-window))))))

-        (if (eq vert t)

-            (setq vert (car fcsb)))

-        (if (eq hor t)

-            (setq hor (cdr fcsb)))))

-    (cons vert hor)))

-

-(defun walk-windows (proc &optional minibuf all-frames)

-  "Cycle through all windows, calling PROC for each one.

-PROC must specify a function with a window as its sole argument.

-The optional arguments MINIBUF and ALL-FRAMES specify the set of

-windows to include in the walk, see also `next-window'.

-

-MINIBUF t means include the minibuffer window even if the

-minibuffer is not active.  MINIBUF nil or omitted means include

-the minibuffer window only if the minibuffer is active.  Any

-other value means do not include the minibuffer window even if

-the minibuffer is active.

-

-Several frames may share a single minibuffer; if the minibuffer

-is active, all windows on all frames that share that minibuffer

-are included 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 nil or omitted means cycle through all windows on

- WINDOW's frame, plus the minibuffer window if specified by the

- MINIBUF argument, see above.  If the minibuffer counts, cycle

- through all windows on all frames that share that minibuffer

- too.

-ALL-FRAMES t means cycle through all windows on all existing

- frames.

-ALL-FRAMES `visible' means cycle through all windows on all

- visible frames.

-ALL-FRAMES 0 means cycle through all windows on all visible and

- iconified frames.

-ALL-FRAMES a frame means cycle through all windows on that frame

- only.

-Anything else means cycle through all windows on WINDOW's frame

- and no others.

-

-This function changes neither the order of recently selected

-windows nor the buffer list."

-  ;; If we start from the minibuffer window, don't fail to come

-  ;; back to it.

-  (when (window-minibuffer-p (selected-window))

-    (setq minibuf t))

-  ;; Make sure to not mess up the order of recently selected

-  ;; windows.  Use `save-selected-window' and `select-window'

-  ;; with second argument non-nil for this purpose.

-  (save-selected-window

-    (when (framep all-frames)

-      (select-window (frame-first-window all-frames) 'norecord))

-    (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.

-More precisely, cycle through all windows using `walk-windows',

-calling the function PREDICATE on each one of them with the

-window as its sole argument.  Return the first window for which

-PREDICATE returns non-nil.  If no window satisfies PREDICATE,

-return DEFAULT.

-

-The optional arguments MINIBUF and ALL-FRAMES specify the set of

-windows to include.  See `walk-windows' for the meaning of these

-arguments."

-  (catch 'found

-    (walk-windows #'(lambda (window)

-                      (when (funcall predicate window)

-                        (throw 'found window)))

-                  minibuf all-frames)

-    default))

-

-(defalias 'some-window 'get-window-with-predicate)

-

-;; This should probably be written in C (i.e., without using `walk-windows').

-(defun get-buffer-window-list (&optional buffer-or-name minibuf all-frames)

-  "Return list of all windows displaying BUFFER-OR-NAME, or nil if none.

-BUFFER-OR-NAME may be a buffer or the name of an existing buffer

-and defaults to the current buffer.

-

-The optional arguments MINIBUF and ALL-FRAMES specify the set of

-windows to consider.  See `walk-windows' for the precise meaning

-of these arguments."

-  (let ((buffer (cond

-                 ((not buffer-or-name) (current-buffer))

-                 ((bufferp buffer-or-name) buffer-or-name)

-                 (t (get-buffer buffer-or-name))))

-        windows)

-    (walk-windows (function (lambda (window)

-                              (if (eq (window-buffer window) buffer)

-                                  (setq windows (cons window windows)))))

-                  minibuf all-frames)

-    windows))

-

-(defun minibuffer-window-active-p (window)

-  "Return t if WINDOW is the currently active minibuffer window."

-  (eq window (active-minibuffer-window)))

-

-(defun count-windows (&optional minibuf)

-   "Return the number of visible windows.

-The optional argument MINIBUF specifies whether the minibuffer

-window shall be counted.  See `walk-windows' for the precise

-meaning of this argument."

-   (let ((count 0))

-     (walk-windows (lambda (w) (setq count (+ count 1)))

-                   minibuf)

-     count))

-

-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

-;;; `balance-windows' subroutines using `window-tree'

-

-;;; Translate from internal window tree format

-

-(defun bw-get-tree (&optional window-or-frame)

-  "Get a window split tree in our format.

-

-WINDOW-OR-FRAME must be nil, a frame, or a window.  If it is nil,

-then the whole window split tree for `selected-frame' is returned.

-If it is a frame, then this is used instead.  If it is a window,

-then the smallest tree containing that window is returned."

-  (when window-or-frame

-    (unless (or (framep window-or-frame)

-                (windowp window-or-frame))

-      (error "Not a frame or window: %s" window-or-frame)))

-  (let ((subtree (bw-find-tree-sub window-or-frame)))

-    (when subtree

-      (if (integerp subtree)

-          nil

-        (bw-get-tree-1 subtree)))))

-

-(defun bw-get-tree-1 (split)

-  (if (windowp split)

-      split

-    (let ((dir (car split))

-          (edges (car (cdr split)))

-          (childs (cdr (cdr split))))

-      (list

-       (cons 'dir (if dir 'ver 'hor))

-       (cons 'b (nth 3 edges))

-       (cons 'r (nth 2 edges))

-       (cons 't (nth 1 edges))

-       (cons 'l (nth 0 edges))

-       (cons 'childs (mapcar #'bw-get-tree-1 childs))))))

-

-(defun bw-find-tree-sub (window-or-frame &optional get-parent)

-  (let* ((window (when (windowp window-or-frame) window-or-frame))

-         (frame (when (windowp window) (window-frame window)))

-         (wt (car (window-tree frame))))

-    (when (< 1 (length (window-list frame 0)))

-      (if window

-          (bw-find-tree-sub-1 wt window get-parent)

-        wt))))

-

-(defun bw-find-tree-sub-1 (tree win &optional get-parent)

-  (unless (windowp win) (error "Not a window: %s" win))

-  (if (memq win tree)

-      (if get-parent

-          get-parent

-        tree)

-    (let ((childs (cdr (cdr tree)))

-          child

-          subtree)

-      (while (and childs (not subtree))

-        (setq child (car childs))

-        (setq childs (cdr childs))

-        (when (and child (listp child))

-          (setq subtree (bw-find-tree-sub-1 child win get-parent))))

-      (if (integerp subtree)

-          (progn

-            (if (= 1 subtree)

-                tree

-              (1- subtree)))

-        subtree

-        ))))

-

-;;; Window or object edges

-

-(defun bw-l (obj)

-  "Left edge of OBJ."

-  (if (windowp obj) (nth 0 (window-edges obj)) (cdr (assq 'l obj))))

-(defun bw-t (obj)

-  "Top edge of OBJ."

-  (if (windowp obj) (nth 1 (window-edges obj)) (cdr (assq 't obj))))

-(defun bw-r (obj)

-  "Right edge of OBJ."

-  (if (windowp obj) (nth 2 (window-edges obj)) (cdr (assq 'r obj))))

-(defun bw-b (obj)

-  "Bottom edge of OBJ."

-  (if (windowp obj) (nth 3 (window-edges obj)) (cdr (assq 'b obj))))

-

-;;; Split directions

-

-(defun bw-dir (obj)

-  "Return window split tree direction if OBJ.

-If OBJ is a window return 'both.  If it is a window split tree

-then return its direction."

-  (if (symbolp obj)

-      obj

-    (if (windowp obj)

-        'both

-      (let ((dir (cdr (assq 'dir obj))))

-        (unless (memq dir '(hor ver both))

-          (error "Can't find dir in %s" obj))

-        dir))))

-

-(defun bw-eqdir (obj1 obj2)

-  "Return t if window split tree directions are equal.

-OBJ1 and OBJ2 should be either windows or window split trees in

-our format.  The directions returned by `bw-dir' are compared and

-t is returned if they are `eq' or one of them is 'both."

-  (let ((dir1 (bw-dir obj1))

-        (dir2 (bw-dir obj2)))

-    (or (eq dir1 dir2)

-        (eq dir1 'both)

-        (eq dir2 'both))))

-

-;;; Building split tree

-

-(defun bw-refresh-edges (obj)

-  "Refresh the edge information of OBJ and return OBJ."

-  (unless (windowp obj)

-    (let ((childs (cdr (assq 'childs obj)))

-          (ol 1000)

-          (ot 1000)

-          (or -1)

-          (ob -1))

-      (dolist (o childs)

-        (when (> ol (bw-l o)) (setq ol (bw-l o)))

-        (when (> ot (bw-t o)) (setq ot (bw-t o)))

-        (when (< or (bw-r o)) (setq or (bw-r o)))

-        (when (< ob (bw-b o)) (setq ob (bw-b o))))

-      (setq obj (delq 'l obj))

-      (setq obj (delq 't obj))

-      (setq obj (delq 'r obj))

-      (setq obj (delq 'b obj))

-      (add-to-list 'obj (cons 'l ol))

-      (add-to-list 'obj (cons 't ot))

-      (add-to-list 'obj (cons 'r or))

-      (add-to-list 'obj (cons 'b ob))

-      ))

-  obj)

-

-;;; Balance windows

-

-(defun balance-windows (&optional window-or-frame)

-  "Make windows the same heights or widths in window split subtrees.

-

-When called non-interactively WINDOW-OR-FRAME may be either a

-window or a frame.  It then balances the windows on the implied

-frame.  If the parameter is a window only the corresponding window

-subtree is balanced."

-  (interactive)

-  (let (

-        (wt (bw-get-tree window-or-frame))

-        (w)

-        (h)

-        (tried-sizes)

-        (last-sizes)

-        (windows (window-list nil 0)))

-    (when wt

-      (while (not (member last-sizes tried-sizes))

-        (when last-sizes (setq tried-sizes (cons last-sizes tried-sizes)))

-        (setq last-sizes (mapcar (lambda (w)

-                                   (window-edges w))

-                                 windows))

-        (when (eq 'hor (bw-dir wt))

-          (setq w (- (bw-r wt) (bw-l wt))))

-        (when (eq 'ver (bw-dir wt))

-          (setq h (- (bw-b wt) (bw-t wt))))

-        (bw-balance-sub wt w h)))))

-

-(defun bw-adjust-window (window delta horizontal)

-  "Wrapper around `adjust-window-trailing-edge' with error checking.

-Arguments WINDOW, DELTA and HORIZONTAL are passed on to that function."

-  ;; `adjust-window-trailing-edge' may fail if delta is too large.

-  (while (>= (abs delta) 1)

-    (condition-case err

-        (progn

-          (adjust-window-trailing-edge window delta horizontal)

-          (setq delta 0))

-      (error

-       ;;(message "adjust: %s" (error-message-string err))

-       (setq delta (/ delta 2))))))

-

-(defun bw-balance-sub (wt w h)

-  (setq wt (bw-refresh-edges wt))

-  (unless w (setq w (- (bw-r wt) (bw-l wt))))

-  (unless h (setq h (- (bw-b wt) (bw-t wt))))

-  (if (windowp wt)

-      (progn

-        (when w

-          (let ((dw (- w (- (bw-r wt) (bw-l wt)))))

-            (when (/= 0 dw)

-              (bw-adjust-window wt dw t))))

-        (when h

-          (let ((dh (- h (- (bw-b wt) (bw-t wt)))))

-            (when (/= 0 dh)

-              (bw-adjust-window wt dh nil)))))

-    (let* ((childs (cdr (assq 'childs wt)))

-           (cw (when w (/ w (if (bw-eqdir 'hor wt) (length childs) 1))))

-           (ch (when h (/ h (if (bw-eqdir 'ver wt) (length childs) 1)))))

-      (dolist (c childs)

-        (bw-balance-sub c cw ch)))))

-

-(defun window-fixed-size-p (&optional window direction)

-  "Return t if WINDOW cannot be resized in DIRECTION.

-WINDOW defaults to the selected window.  DIRECTION can be

-nil (i.e. any), `height' or `width'."

-  (with-current-buffer (window-buffer window)

-    (when (and (boundp 'window-size-fixed) window-size-fixed)

-      (not (and direction

-                (member (cons direction window-size-fixed)

-                        '((height . width) (width . height))))))))

-

-;;; A different solution to balance-windows.

-

-(defvar window-area-factor 1

-  "Factor by which the window area should be over-estimated.

-This is used by `balance-windows-area'.

-Changing this globally has no effect.")

-(make-variable-buffer-local 'window-area-factor)

-

-(defun balance-windows-area ()

-  "Make all visible windows the same area (approximately).

-See also `window-area-factor' to change the relative size of

-specific buffers."

-  (interactive)

-  (let* ((unchanged 0) (carry 0) (round 0)

-         ;; Remove fixed-size windows.

-         (wins (delq nil (mapcar (lambda (win)

-                                   (if (not (window-fixed-size-p win)) win))

-                                 (window-list nil 'nomini))))

-         (changelog nil)

-         next)

-    ;; Resizing a window changes the size of surrounding windows in complex

-    ;; ways, so it's difficult to balance them all.  The introduction of

-    ;; `adjust-window-trailing-edge' made it a bit easier, but it is still

-    ;; very difficult to do.  `balance-window' above takes an off-line

-    ;; approach: get the whole window tree, then balance it, then try to

-    ;; adjust the windows so they fit the result.

-    ;; Here, instead, we take a "local optimization" approach, where we just

-    ;; go through all the windows several times until nothing needs to be

-    ;; changed.  The main problem with this approach is that it's difficult

-    ;; to make sure it terminates, so we use some heuristic to try and break

-    ;; off infinite loops.

-    ;; After a round without any change, we allow a second, to give a chance

-    ;; to the carry to propagate a minor imbalance from the end back to

-    ;; the beginning.

-    (while (< unchanged 2)

-      ;; (message "New round")

-      (setq unchanged (1+ unchanged) round (1+ round))

-      (dolist (win wins)

-        (setq next win)

-        (while (progn (setq next (next-window next))

-                      (window-fixed-size-p next)))

-        ;; (assert (eq next (or (cadr (member win wins)) (car wins))))

-        (let* ((horiz

-                (< (car (window-edges win)) (car (window-edges next))))

-               (areadiff (/ (- (* (window-height next) (window-width next)

-                                  (buffer-local-value 'window-area-factor

-                                                      (window-buffer next)))

-                               (* (window-height win) (window-width win)

-                                  (buffer-local-value 'window-area-factor

-                                                      (window-buffer win))))

-                            (max (buffer-local-value 'window-area-factor

-                                                     (window-buffer win))

-                                 (buffer-local-value 'window-area-factor

-                                                     (window-buffer next)))))

-               (edgesize (if horiz

-                             (+ (window-height win) (window-height next))

-                           (+ (window-width win) (window-width next))))

-               (diff (/ areadiff edgesize)))

-          (when (zerop diff)

-            ;; Maybe diff is actually closer to 1 than to 0.

-            (setq diff (/ (* 3 areadiff) (* 2 edgesize))))

-          (when (and (zerop diff) (not (zerop areadiff)))

-            (setq diff (/ (+ areadiff carry) edgesize))

-            ;; Change things smoothly.

-            (if (or (> diff 1) (< diff -1)) (setq diff (/ diff 2))))

-          (if (zerop diff)

-              ;; Make sure negligible differences don't accumulate to

-              ;; become significant.

-              (setq carry (+ carry areadiff))

-            (bw-adjust-window win diff horiz)

-            ;; (sit-for 0.5)

-            (let ((change (cons win (window-edges win))))

-              ;; If the same change has been seen already for this window,

-              ;; we're most likely in an endless loop, so don't count it as

-              ;; a change.

-              (unless (member change changelog)

-                (push change changelog)

-                (setq unchanged 0 carry 0)))))))

-    ;; We've now basically balanced all the windows.

-    ;; But there may be some minor off-by-one imbalance left over,

-    ;; so let's do some fine tuning.

-    ;; (bw-finetune wins)

-    ;; (message "Done in %d rounds" round)

-    ))

-

-

-(defcustom display-buffer-function nil

-  "If non-nil, function to call to handle `display-buffer'.

-It will receive two args, the buffer and a flag which if non-nil

-means that the currently selected window is not acceptable.  It

-should choose or create a window, display the specified buffer in

-it, and return the window.

-

-Commands such as `switch-to-buffer-other-window' and

-`find-file-other-window' work using this function."

-  :type '(choice

-          (const nil)

-          (function :tag "function"))

-  :group 'windows)

-

-(defun special-display-p (buffer-name)

-  "Return non-nil if a buffer named BUFFER-NAME gets a special frame.

-If the value is t, `display-buffer' or `pop-to-buffer' would

-create a special frame for that buffer using the default frame

-parameters.

-

-If the value is a list, it is a list of frame parameters that

-would be used to make a frame for that buffer.  The variables

-`special-display-buffer-names' and `special-display-regexps'

-control this."

-  (let (tmp)

-  (cond

-   ((not (stringp buffer-name)))

-   ;; Make sure to return t in the following two cases.

-   ((member buffer-name special-display-buffer-names) t)

-     ((setq tmp (assoc buffer-name special-display-buffer-names)) (cdr tmp))

-   ((catch 'found

-      (dolist (regexp special-display-regexps)

-        (cond

-         ((stringp regexp)

-          (when (string-match-p regexp buffer-name)

-            (throw 'found t)))

-         ((and (consp regexp) (stringp (car regexp))

-               (string-match-p (car regexp) buffer-name))

-            (throw 'found (cdr regexp))))))))))

-

-(defcustom special-display-buffer-names nil

-  "List of buffer names that should have their own special frames.

-Displaying a buffer with `display-buffer' or `pop-to-buffer', if

-its name is in this list, makes a special frame for it using

-`special-display-function'.  See also `special-display-regexps'.

-

-An element of the list can be a list instead of just a string.

-There are two ways to use a list as an element:

-  (BUFFER FRAME-PARAMETERS...)  (BUFFER FUNCTION OTHER-ARGS...)

-In the first case, the FRAME-PARAMETERS are pairs of the form

-\(PARAMETER . VALUE); these parameter values are used to create

-the frame.  In the second case, FUNCTION is called with BUFFER as

-the first argument, followed by the OTHER-ARGS--it can display

-BUFFER in any way it likes.  All this is done by the function

-found in `special-display-function'.

-

-If the specified frame parameters include (same-buffer . t), the

-buffer is displayed in the currently selected window.  Otherwise, if

-they include (same-frame . t), the buffer is displayed in a new window

-in the currently selected frame.

-

-If this variable appears \"not to work\", because you add a name to it

-but that buffer still appears in the selected window, look at the

-values of `same-window-buffer-names' and `same-window-regexps'.

-Those variables take precedence over this one."

-  :type '(repeat (choice :tag "Buffer"

-                         :value ""

-                         (string :format "%v")

-                         (cons :tag "With attributes"

-                               :format "%v"

-                               :value ("" . nil)

-                               (string :format "%v")

-                               (repeat :tag "Attributes"

-                                       (cons :format "%v"

-                                             (symbol :tag "Parameter")

-                                             (sexp :tag "Value"))))))

-  :group 'frames)

-

-(defcustom special-display-regexps nil

-  "List of regexps saying which buffers should have their own special frames.

-When displaying a buffer with `display-buffer' or

-`pop-to-buffer', if any regexp in this list matches the buffer

-name, it makes a special frame for the buffer by calling

-`special-display-function'.

-

-An element of the list can be a list instead of just a string.

-There are two ways to use a list as an element:

-  (REGEXP FRAME-PARAMETERS...)  (REGEXP FUNCTION OTHER-ARGS...)

-In the first case, the FRAME-PARAMETERS are pairs of the form

-\(PARAMETER . VALUE); these parameter values are used to create

-the frame.  In the second case, FUNCTION is called with BUFFER as

-the first argument, followed by the OTHER-ARGS--it can display

-the buffer in any way it likes.  All this is done by the function

-found in `special-display-function'.

-

-If the specified frame parameters include (same-buffer . t), the

-buffer is displayed in the currently selected window.  Otherwise,

-if they include (same-frame . t), the buffer is displayed in a

-new window in the currently selected frame.

-

-If this variable appears \"not to work\", because you add a

-regexp to it but the matching buffers still appear in the

-selected window, look at the values of `same-window-buffer-names'

-and `same-window-regexps'.  Those variables take precedence over

-this one."

-  :type '(repeat (choice :tag "Buffer"

-                         :value ""

-                         (regexp :format "%v")

-                         (cons :tag "With attributes"

-                               :format "%v"

-                               :value ("" . nil)

-                               (regexp :format "%v")

-                               (repeat :tag "Attributes"

-                                       (cons :format "%v"

-                                             (symbol :tag "Parameter")

-                                             (sexp :tag "Value"))))))

-  :group 'frames)

-

-(defcustom special-display-function 'special-display-popup-frame

-  "Function to call to make a new frame for a special buffer.

-It is called with two arguments, the buffer and optional buffer

-specific data, and should return a window displaying that buffer.

-The default value normally makes a separate frame for the buffer,

-using `special-display-frame-alist' to specify the frame

-parameters.

-

-But if the buffer specific data includes (same-buffer . t) then

-the buffer is displayed in the current selected window.

-Otherwise if it includes (same-frame . t) then the buffer is

-displayed in a new window in the currently selected frame.

-

-A buffer is special if it is listed in

-`special-display-buffer-names' or matches a regexp in

-`special-display-regexps'."

-  :type 'function

-  :group 'frames)

-

-(defun same-window-p (buffer-name)

-  "Return non-nil if a buffer named BUFFER-NAME would be shown in the \"same\" window.

-This function returns non-nil if `display-buffer' or

-`pop-to-buffer' would show a buffer named BUFFER-NAME in the

-selected rather than \(as usual\) some other window.  See

-`same-window-buffer-names' and `same-window-regexps'."

-  (cond

-   ((not (stringp buffer-name)))

-   ;; The elements of `same-window-buffer-names' can be buffer

-   ;; names or cons cells whose cars are buffer names.

-   ((member buffer-name same-window-buffer-names))

-   ((assoc buffer-name same-window-buffer-names))

-   ((catch 'found

-      (dolist (regexp same-window-regexps)

-        ;; The elements of `same-window-regexps' can be regexps

-        ;; or cons cells whose cars are regexps.

-        (when (or (and (stringp regexp)

-                       (string-match regexp buffer-name))

-                  (and (consp regexp) (stringp (car regexp))

-                       (string-match-p (car regexp) buffer-name)))

-          (throw 'found t)))))))

-

-(defcustom same-window-buffer-names nil

-  "List of names of buffers that should appear in the \"same\" window.

-`display-buffer' and `pop-to-buffer' show a buffer whose name is

-on this list in the selected rather than some other window.

-

-An element of this list can be a cons cell instead of just a

-string.  In that case the car must be a string specifying the

-buffer name.  This is for compatibility with

-`special-display-buffer-names'; the cdr of the cons cell is

-ignored.

-

-See also `same-window-regexps'."

- :type '(repeat (string :format "%v"))

- :group 'windows)

-

-(defcustom same-window-regexps nil

-  "List of regexps saying which buffers should appear in the \"same\" window.

-`display-buffer' and `pop-to-buffer' show a buffer whose name

-matches a regexp on this list in the selected rather than some

-other window.

-

-An element of this list can be a cons cell instead of just a

-string.  In that case the car must be a string, which specifies

-the buffer name.  This is for compatibility with

-`special-display-buffer-names'; the cdr of the cons cell is

-ignored.

-

-See also `same-window-buffer-names'."

-  :type '(repeat (regexp :format "%v"))

-  :group 'windows)

-

-(defcustom pop-up-frames nil

-  "Whether `display-buffer' should make a separate frame.

-If nil, never make a seperate frame.

-If the value is `graphic-only', make a separate frame

-on graphic displays only.

-Any other non-nil value means always make a separate frame."

-  :type '(choice

-          (const :tag "Never" nil)

-          (const :tag "On graphic displays only" graphic-only)

-          (const :tag "Always" t))

-  :group 'windows)

-

-(defcustom display-buffer-reuse-frames nil

-  "Non-nil means `display-buffer' should reuse frames.

-If the buffer in question is already displayed in a frame, raise

-that frame."

-  :type 'boolean

-  :version "21.1"

-  :group 'windows)

-

-(defcustom pop-up-windows t

-  "Non-nil means `display-buffer' should make a new window."

-  :type 'boolean

-  :group 'windows)

-

-(defcustom split-height-threshold 80

-  "Minimum height of window to be split vertically.

-If the value is a number, `display-buffer' can split a window

-only if it has at least as many lines.  If the value is nil,

-`display-buffer' cannot split a window vertically.

-

-If the window is the only window on its frame, `display-buffer'

-can split it regardless of this value."

-  :type '(choice (const nil) (number :tag "lines"))

-  :version "23.1"

-  :group 'windows)

-

-(defcustom split-width-threshold 160

-  "Minimum width of window to be split horizontally.

-If the value is a number, `display-buffer' can split a window

-only if it has at least as many columns.  If the value is nil,

-`display-buffer' cannot split a window horizontally."

-  :type '(choice (const nil) (number :tag "columns"))

-  :version "23.1"

-  :group 'windows)

-

-(defcustom split-window-preferred-function nil

-  "Function used by `display-buffer' to split windows.

-If non-nil, a function called with a window as single argument

-supposed to split that window and return the new window.  If the

-function returns nil the window is not split.

-

-If nil, `display-buffer' will split the window respecting the

-values of `split-height-threshold' and `split-width-threshold'."

-  :type '(choice (const nil) (function :tag "Function"))

-  :version "23.1"

-  :group 'windows)

-

-(defun window--splittable-p (window &optional horizontal)

-  "Return non-nil if WINDOW can be split evenly.

-Optional argument HORIZONTAL non-nil means check whether WINDOW

-can be split horizontally.

-

-WINDOW can be split vertically when the following conditions

-hold:

-

-- `window-size-fixed' is either nil or equals `width' for the

-  buffer of WINDOW.

-

-- `split-height-threshold' is a number and WINDOW is at least as

-  high as `split-height-threshold'.

-

-- When WINDOW is split evenly, the emanating windows are at least

-  `window-min-height' lines tall and can accommodate at least one

-  line plus - if WINDOW has one - a mode line.

-

-WINDOW can be split horizontally when the following conditions

-hold:

-

-- `window-size-fixed' is either nil or equals `height' for the

-  buffer of WINDOW.

-

-- `split-width-threshold' is a number and WINDOW is at least as

-  wide as `split-width-threshold'.

-

-- When WINDOW is split evenly, the emanating windows are at least

-  `window-min-width' or two (whichever is larger) columns wide."

-  (when (window-live-p window)

-    (with-current-buffer (window-buffer window)

-      (if horizontal

-          ;; A window can be split horizontally when its width is not

-          ;; fixed, it is at least `split-width-threshold' columns wide

-          ;; and at least twice as wide as `window-min-width' and 2 (the

-          ;; latter value is hardcoded).

-          (and (memq window-size-fixed '(nil height))

-               ;; Testing `window-full-width-p' here hardly makes any

-               ;; sense nowadays.  This can be done more intuitively by

-               ;; setting up `split-width-threshold' appropriately.

-               (numberp split-width-threshold)

-               (>= (window-width window)

-                   (max split-width-threshold

-                        (* 2 (max window-min-width 2)))))

-        ;; A window can be split vertically when its height is not

-        ;; fixed, it is at least `split-height-threshold' lines high,

-        ;; and it is at least twice as high as `window-min-height' and 2

-        ;; if it has a modeline or 1.

-        (and (memq window-size-fixed '(nil width))

-             (numberp split-height-threshold)

-             (>= (window-height window)

-                 (max split-height-threshold

-                      (* 2 (max window-min-height

-                                (if mode-line-format 2 1))))))))))

-

-(defun window--try-to-split-window (window)

-  "Split WINDOW if it is splittable.

-See `window--splittable-p' for how to determine whether a window

-is splittable.  If WINDOW can be split, return the value returned

-by `split-window' (or `split-window-preferred-function')."

-  (when (and (window-live-p window)

-             (not (frame-parameter (window-frame window) 'unsplittable)))

-    (if (functionp split-window-preferred-function)

-        ;; `split-window-preferred-function' is specified, so use it.

-        (funcall split-window-preferred-function window)

-      (or (and (window--splittable-p window)

-               ;; Split window vertically.

-               (split-window window))

-          (and (window--splittable-p window t)

-               ;; Split window horizontally.

-               (split-window window nil t))

-          (and (eq window (frame-root-window (window-frame window)))

-               (not (window-minibuffer-p window))

-               ;; If WINDOW is the only window on its frame and not the

-               ;; minibuffer window, attempt to split it vertically

-               ;; disregarding the value of `split-height-threshold'.

-               (let ((split-height-threshold 0))

-                 (and (window--splittable-p window)

-                      (split-window window))))))))

-

-(defun window--frame-usable-p (frame)

-  "Return FRAME if it can be used to display a buffer."

-  (when (frame-live-p frame)

-    (let ((window (frame-root-window frame)))

-      ;; `frame-root-window' may be an internal window which is considered

-      ;; "dead" by `window-live-p'.  Hence if `window' is not live we

-      ;; implicitly know that `frame' has a visible window we can use.

-      (when (or (not (window-live-p window))

-                (and (not (window-minibuffer-p window))

-                     (not (window-dedicated-p window))))

-        frame))))

-

-(defcustom even-window-heights t

-  "If non-nil `display-buffer' will try to even window heights.

-Otherwise `display-buffer' will leave the window configuration

-alone.  Heights are evened only when `display-buffer' chooses a

-window that appears above or below the selected window."

-  :type 'boolean

-  :group 'windows)

-

-(defun window--even-window-heights (window)

-  "Even heights of WINDOW and selected window.

-Do this only if these windows are vertically adjacent to each

-other, `even-window-heights' is non-nil, and the selected window

-is higher than WINDOW."

-  (when (and even-window-heights

-             (not (eq window (selected-window)))

-             ;; Don't resize minibuffer windows.

-             (not (window-minibuffer-p (selected-window)))

-             (> (window-height (selected-window)) (window-height window)) 

-             (eq (window-frame window) (window-frame (selected-window)))

-             (let ((sel-edges (window-edges (selected-window)))

-                   (win-edges (window-edges window)))

-               (and (= (nth 0 sel-edges) (nth 0 win-edges))

-                    (= (nth 2 sel-edges) (nth 2 win-edges))

-                    (or (= (nth 1 sel-edges) (nth 3 win-edges))

-                        (= (nth 3 sel-edges) (nth 1 win-edges))))))

-    (let ((window-min-height 1))

-      ;; Don't throw an error if we can't even window heights for

-      ;; whatever reason.

-      (condition-case nil

-          (enlarge-window (/ (- (window-height window) (window-height)) 2))

-        (error nil)))))

-

-(defun window--display-buffer-1 (window)

-  "Raise the frame containing WINDOW.

-Do not raise the selected frame.  Return WINDOW."

-  (let* ((frame (window-frame window))

-         (visible (frame-visible-p frame)))

-    (unless (or (not visible)

-                ;; Assume the selected frame is already visible enough.

-                (eq frame (selected-frame))

-                ;; Assume the frame from which we invoked the minibuffer

-                ;; is visible.

-                (and (minibuffer-window-active-p (selected-window))

-                     (eq frame (window-frame (minibuffer-selected-window)))))

-      (raise-frame frame))

-    window))

-

-(defun window--display-buffer-2 (buffer window)

-  "Display BUFFER in WINDOW and make its frame visible.

-Return WINDOW."

-  (when (and (buffer-live-p buffer) (window-live-p window))

-    (set-window-buffer window buffer)

-    (window--display-buffer-1 window)))

-

-(defun display-buffer (buffer-or-name &optional not-this-window frame)

-  "Make buffer BUFFER-OR-NAME appear in some window but don't select it.

-BUFFER-OR-NAME must be a buffer or the name of an existing

-buffer.  Return the window chosen to display BUFFER-OR-NAME or

-nil if no such window is found.

-

-Optional argument NOT-THIS-WINDOW non-nil means display the

-buffer in a window other than the selected one, even if it is

-already displayed in the selected window.

-

-Optional argument FRAME specifies which frames to investigate

-when the specified buffer is already displayed.  If the buffer is

-already displayed in some window on one of these frames simply

-return that window.  Possible values of FRAME are:

-

-`visible' - consider windows on all visible frames.

-

-0 - consider windows on all visible or iconified frames.

-

-t - consider windows on all frames.

-

-A specific frame - consider windows on that frame only.

-

-nil - consider windows on the selected frame \(actually the

-last non-minibuffer frame\) only.  If, however, either

-`display-buffer-reuse-frames' or `pop-up-frames' is non-nil

-\(non-nil and not graphic-only on a text-only terminal),

-consider all visible or iconified frames."

-  (interactive "BDisplay buffer:\nP")

-  (let* ((can-use-selected-window

-          ;; The selected window is usable unless either NOT-THIS-WINDOW

-          ;; is non-nil, it is dedicated to its buffer, or it is the

-          ;; `minibuffer-window'.

-          (not (or not-this-window

-                   (window-dedicated-p (selected-window))

-                   (window-minibuffer-p))))

-         (buffer (if (bufferp buffer-or-name)

-                     buffer-or-name

-                   (get-buffer buffer-or-name)))

-         (name-of-buffer (buffer-name buffer))

-         ;; On text-only terminals do not pop up a new frame when

-         ;; `pop-up-frames' equals graphic-only.

-         (use-pop-up-frames (if (eq pop-up-frames 'graphic-only)

-                                (display-graphic-p)

-                              pop-up-frames))

-         ;; `frame-to-use' is the frame where to show `buffer' - either

-         ;; the selected frame or the last nonminibuffer frame.

-         (frame-to-use

-          (or (window--frame-usable-p (selected-frame))

-              (window--frame-usable-p (last-nonminibuffer-frame))))

-         ;; `window-to-use' is the window we use for showing `buffer'.

-         window-to-use)

-    (cond

-     ((not (buffer-live-p buffer))

-      (error "No such buffer %s" buffer))

-     (display-buffer-function

-      ;; Let `display-buffer-function' do the job.

-      (funcall display-buffer-function buffer not-this-window))

-     ((and (not not-this-window)

-           (eq (window-buffer (selected-window)) buffer))

-      ;; The selected window already displays BUFFER and

-      ;; `not-this-window' is nil, so use it.

-      (window--display-buffer-1 (selected-window)))

-     ((and can-use-selected-window (same-window-p name-of-buffer))

-      ;; If the buffer's name tells us to use the selected window do so.

-      (window--display-buffer-2 buffer (selected-window)))

-     ((let ((frames (or frame

-                        (and (or use-pop-up-frames

-                                 display-buffer-reuse-frames

-                                 (not (last-nonminibuffer-frame)))

-                             0)

-                        (last-nonminibuffer-frame))))

-        (and (setq window-to-use (get-buffer-window buffer frames))

-             (or can-use-selected-window

-                 (not (eq (selected-window) window-to-use)))))

-      ;; If the buffer is already displayed in some window use that.

-      (window--display-buffer-1 window-to-use))

-     ((and special-display-function

-           ;; `special-display-p' returns either t or a list of frame

-           ;; parameters to pass to `special-display-function'.

-           (let ((pars (special-display-p name-of-buffer)))

-             (when pars

-               (funcall special-display-function

-                        buffer (if (listp pars) pars))))))

-     ((or use-pop-up-frames (not frame-to-use))

-      ;; We want or need a new frame.

-      (window--display-buffer-2

-       buffer (frame-selected-window (funcall pop-up-frame-function))))

-     ((and pop-up-windows

-           ;; Make a new window.

-           (or (not (frame-parameter frame-to-use 'unsplittable))

-               ;; If the selected frame cannot be split look at

-               ;; `last-nonminibuffer-frame'.

-               (and (eq frame-to-use (selected-frame))

-                    (setq frame-to-use (last-nonminibuffer-frame))

-                    (window--frame-usable-p frame-to-use)

-                    (not (frame-parameter frame-to-use 'unsplittable))))

-           ;; Attempt to split largest or least recently used window.

-           (setq window-to-use

-                 (or (window--try-to-split-window

-                      (get-largest-window frame-to-use t))

-                     (window--try-to-split-window

-                      (get-lru-window frame-to-use t))))

-           (window--display-buffer-2 buffer window-to-use)))

-     ((setq window-to-use

-            ;; Reuse an existing window.

-            (or (get-lru-window frame-to-use)

-                (get-buffer-window buffer 'visible)

-                (get-largest-window 'visible nil)

-                (get-buffer-window buffer 0)

-                (get-largest-window 0 nil)

-                (frame-selected-window (funcall pop-up-frame-function))))

-      (window--even-window-heights window-to-use)

-      (window--display-buffer-2 buffer window-to-use)))))

-

-(defun pop-to-buffer (buffer-or-name &optional other-window norecord)

-  "Select buffer BUFFER-OR-NAME in some window, preferably a different one.

-BUFFER-OR-NAME may be a buffer, a string \(a buffer name), or

-nil.  If BUFFER-OR-NAME is a string not naming an existent

-buffer, create a buffer with that name.  If BUFFER-OR-NAME is

-nil, choose some other buffer.

-

-If `pop-up-windows' is non-nil, windows can be split to display

-the buffer.  If optional second arg OTHER-WINDOW is non-nil,

-insist on finding another window even if the specified buffer is

-already visible in the selected window, and ignore

-`same-window-regexps' and `same-window-buffer-names'.

-

-If the window to show BUFFER-OR-NAME is not on the selected

-frame, raise that window's frame and give it input focus.

-

-This function returns the buffer it switched to.  This uses the

-function `display-buffer' as a subroutine; see the documentation

-of `display-buffer' for additional customization information.

-

-Optional third arg NORECORD non-nil means do not put this buffer

-at the front of the list of recently selected ones."

-  (let ((buffer

-         ;; FIXME: This behavior is carried over from the previous C version

-         ;; of pop-to-buffer, but really we should use just

-         ;; `get-buffer' here.

-         (if (null buffer-or-name) (other-buffer (current-buffer))

-           (or (get-buffer buffer-or-name)

-               (let ((buf (get-buffer-create buffer-or-name)))

-                 (set-buffer-major-mode buf)

-                 buf))))

-        (old-window (selected-window))

-        (old-frame (selected-frame))

-        new-window new-frame)

-    (set-buffer buffer)

-    (setq new-window (display-buffer buffer other-window))

-    (unless (eq new-window old-window)

-      ;; `display-buffer' has chosen another window, select it.

-      (select-window new-window norecord)

-      (setq new-frame (window-frame new-window))

-      (unless (eq new-frame old-frame)

-        ;; `display-buffer' has chosen another frame, make sure it gets

-        ;; input focus and is risen.

-        (select-frame-set-input-focus new-frame)))

-    buffer))

-

-;; I think this should be the default; I think people will prefer it--rms.

-(defcustom split-window-keep-point t

-  "If non-nil, \\[split-window-vertically] 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.

-

-This option applies only to `split-window-vertically' and

-functions that call it.  `split-window' always keeps the original

-point in both children."

-  :type 'boolean

-  :group 'windows)

-

-(defun split-window-vertically (&optional size)

-  "Split selected window into two windows, one above the other.

-The upper window gets SIZE lines and the lower one gets the rest.

-SIZE negative means the lower window gets -SIZE lines and the

-upper one the rest.  With no argument, split windows 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 will get the same value of point as the selected window.

-This is often more convenient for editing.  The upper window is

-the selected window.

-

-Otherwise, we choose 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.

-

-Regardless of the value of `split-window-keep-point', the upper

-window is the original one and the return value is the new, lower

-window."

-  (interactive "P")

-  (let ((old-window (selected-window))

-        (old-point (point))

-        (size (and size (prefix-numeric-value size)))

-        moved-by-window-height moved new-window bottom)

-    (and size (< size 0)

-         ;; Handle negative SIZE value.

-         (setq size (+ (window-height) size)))

-    (setq new-window (split-window nil size))

-    (unless split-window-keep-point

-      (save-excursion

-        (set-buffer (window-buffer))

-        (goto-char (window-start))

-        (setq moved (vertical-motion (window-height)))

-        (set-window-start new-window (point))

-        (when (> (point) (window-point new-window))

-          (set-window-point new-window (point)))

-        (when (= moved (window-height))

-          (setq moved-by-window-height t)

-          (vertical-motion -1))

-        (setq bottom (point)))

-      (and moved-by-window-height

-           (<= bottom (point))

-           (set-window-point old-window (1- bottom)))

-      (and moved-by-window-height

-           (<= (window-start new-window) old-point)

-           (set-window-point new-window old-point)

-           (select-window new-window)))

-    (split-window-save-restore-data new-window old-window)))

-

-;; This is to avoid compiler warnings.

-(defvar view-return-to-alist)

-

-(defun split-window-save-restore-data (new-window old-window)

-  (with-current-buffer (window-buffer)

-    (when view-mode

-      (let ((old-info (assq old-window view-return-to-alist)))

-        (when old-info

-          (push (cons new-window (cons (car (cdr old-info)) t))

-                view-return-to-alist))))

-    new-window))

-

-(defun split-window-horizontally (&optional size)

-  "Split selected window into two windows side by side.

-The selected window becomes the left one and gets SIZE columns.

-SIZE negative means the right window gets -SIZE lines.

-

-SIZE 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.  SIZE omitted or nil means split

-window equally.

-

-The selected window remains selected.  Return the new window."

-  (interactive "P")

-  (let ((old-window (selected-window))

-        (size (and size (prefix-numeric-value size))))

-    (and size (< size 0)

-         ;; Handle negative SIZE value.

-         (setq size (+ (window-width) size)))

-    (split-window-save-restore-data (split-window nil size t) old-window)))

-

-

-(defun set-window-text-height (window height)

-  "Sets the height in lines of the text display area of WINDOW to HEIGHT.

-HEIGHT doesn't include the mode line or header line, if any, or

-any partial-height lines in the text display area.

-

-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)

-      ;; Setting window-min-height to a value like 1 can lead to very

-      ;; bizarre displays because it also allows Emacs to make *other*

-      ;; windows 1-line tall, which means that there's no more space for

-      ;; the modeline.

-      (let ((window-min-height (min 2 height))) ; One text line plus a modeline.

-        (if (and window (not (eq window (selected-window))))

-            (save-selected-window

-              (select-window window 'norecord)

-              (enlarge-window delta))

-          (enlarge-window delta))))))

-

-

-(defun enlarge-window-horizontally (columns)

-  "Make selected window COLUMNS wider.

-Interactively, if no argument is given, make selected window one

-column wider."

-  (interactive "p")

-  (enlarge-window columns t))

-

-(defun shrink-window-horizontally (columns)

-  "Make selected window COLUMNS narrower.

-Interactively, if no argument is given, make selected window one

-column narrower."

-  (interactive "p")

-  (shrink-window columns t))

-

-(defun window-buffer-height (window)

-  "Return the height (in screen lines) of the buffer that WINDOW is displaying."

-  (with-current-buffer (window-buffer window)

-    (max 1

-         (count-screen-lines (point-min) (point-max)

-                             ;; If buffer ends with a newline, ignore it when

-                             ;; counting height unless point is after it.

-                             (eobp)

-                             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)

-  "Adjust height of WINDOW to display its buffer's contents exactly.

-WINDOW defaults to the selected window.

-Optional argument MAX-HEIGHT specifies the maximum height of the

-window and defaults to the height of WINDOW's frame.

-Optional argument MIN-HEIGHT specifies the minimum height of the

-window and defaults to `window-min-height'.

-Both, MAX-HEIGHT and MIN-HEIGHT are specified in lines and

-include the mode line and header line, if any.

-Always return nil."

-  (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)))

-

-    ;; 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 'norecord)

-

-      ;; 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 window-safely-shrinkable-p (&optional window)

-  "Return t if WINDOW can be shrunk without shrinking other windows.

-WINDOW defaults to the selected window."

-  (with-selected-window (or window (selected-window))

-    (let ((edges (window-edges)))

-      (or (= (nth 2 edges) (nth 2 (window-edges (previous-window))))

-          (= (nth 0 edges) (nth 0 (window-edges (next-window))))))))

-

-(defun shrink-window-if-larger-than-buffer (&optional window)

-  "Shrink height of WINDOW if its buffer doesn't need so many lines.

-More precisely, shrink WINDOW vertically to be as small as

-possible, while still showing the full contents of its buffer.

-WINDOW 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, nil otherwise."

-  (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 window)

-             (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)

-  (let ((window-to-delete (selected-window))

-        (buffer-to-kill (current-buffer))

-        (delete-window-hook (lambda ()

-                              (condition-case nil

-                                  (delete-window)

-                                (error nil)))))

-    (unwind-protect

-        (progn

-          (add-hook 'kill-buffer-hook delete-window-hook t t)

-          (if (kill-buffer (current-buffer))

-              ;; If `delete-window' failed before, we rerun it to regenerate

-              ;; the error so it can be seen in the echo area.

-              (when (eq (selected-window) window-to-delete)

-                (delete-window))))

-      ;; If the buffer is not dead for some reason (probably because

-      ;; of a `quit' signal), remove the hook again.

-      (condition-case nil

-          (with-current-buffer buffer-to-kill

-            (remove-hook 'kill-buffer-hook delete-window-hook t))

-        (error nil)))))

-

-(defun quit-window (&optional kill window)

-  "Quit WINDOW and bury its buffer.

-With a prefix argument, kill the buffer instead.  WINDOW defaults

-to the selected window.

-

-If WINDOW is non-nil, dedicated, or a minibuffer window, delete

-it and, if it's alone on its frame, its frame too.  Otherwise, or

-if deleting WINDOW fails in any of the preceding cases, display

-another buffer in WINDOW using `switch-to-buffer'.

-

-Optional argument KILL non-nil means kill WINDOW's buffer.

-Otherwise, bury WINDOW's buffer, see `bury-buffer'."

-  (interactive "P")

-  (let ((buffer (window-buffer window)))

-    (if (or window

-            (window-minibuffer-p window)

-            (window-dedicated-p window))

-        ;; WINDOW is either non-nil, a minibuffer window, or dedicated;

-        ;; try to delete it.

-        (let ((frame (window-frame (or window (selected-window)))))

-          (if (eq window (frame-root-window frame))

-              ;; WINDOW is alone on its frame.  `delete-windows-on'

-              ;; knows how to handle that case.

-              (delete-windows-on buffer frame)

-            ;; There are other windows on its frame, delete WINDOW.

-            (delete-window window)))

-      ;; Otherwise, switch to another buffer in the selected window.

-      (switch-to-buffer nil))

-

-    ;; Deal with the buffer.

-    (if kill

-        (kill-buffer buffer)

-      (bury-buffer buffer))))

-

-(defvar recenter-last-op nil

-  "Indicates the last recenter operation performed.

-Possible values: `top', `middle', `bottom'.")

-

-(defun recenter-top-bottom (&optional arg)

-  "Move current line to window center, top, and bottom, successively.

-With no prefix argument, the first call redraws the frame and

- centers point vertically within the window.  Successive calls

- scroll the window, placing point on the top, bottom, and middle

- consecutively.  The cycling order is middle -> top -> bottom.

-

-A prefix argument is handled like `recenter':

- With numeric prefix ARG, move current line to window-line ARG.

- With plain `C-u', move current line to window center.

-

-Top and bottom destinations are actually `scroll-margin' lines

- the from true window top and bottom."

-  (interactive "P")

-  (cond

-   (arg (recenter arg))                 ; Always respect ARG.

-   ((or (not (eq this-command last-command))

-        (eq recenter-last-op 'bottom))

-    (setq recenter-last-op 'middle)

-    (recenter))

-   (t

-    (let ((this-scroll-margin

-           (min (max 0 scroll-margin)

-                (truncate (/ (window-body-height) 4.0)))))

-      (cond ((eq recenter-last-op 'middle)

-             (setq recenter-last-op 'top)

-             (recenter this-scroll-margin))

-            ((eq recenter-last-op 'top)

-             (setq recenter-last-op 'bottom)

-             (recenter (- -1 this-scroll-margin))))))))

-

-(define-key global-map [?\C-l] 'recenter-top-bottom)

-

-(defvar mouse-autoselect-window-timer nil

-  "Timer used by delayed window autoselection.")

-

-(defvar mouse-autoselect-window-position nil

-  "Last mouse position recorded by delayed window autoselection.")

-

-(defvar mouse-autoselect-window-window nil

-  "Last window recorded by delayed window autoselection.")

-

-(defvar mouse-autoselect-window-state nil

-  "When non-nil, special state of delayed window autoselection.

-Possible values are `suspend' \(suspend autoselection after a menu or

-scrollbar interaction\) and `select' \(the next invocation of

-'handle-select-window' shall select the window immediately\).")

-

-(defun mouse-autoselect-window-cancel (&optional force)

-  "Cancel delayed window autoselection.

-Optional argument FORCE means cancel unconditionally."

-  (unless (and (not force)

-               ;; Don't cancel for select-window or select-frame events

-               ;; or when the user drags a scroll bar.

-               (or (memq this-command

-                         '(handle-select-window handle-switch-frame))

-                   (and (eq this-command 'scroll-bar-toolkit-scroll)

-                        (memq (nth 4 (event-end last-input-event))

-                              '(handle end-scroll)))))

-    (setq mouse-autoselect-window-state nil)

-    (when (timerp mouse-autoselect-window-timer)

-      (cancel-timer mouse-autoselect-window-timer))

-    (remove-hook 'pre-command-hook 'mouse-autoselect-window-cancel)))

-

-(defun mouse-autoselect-window-start (mouse-position &optional window suspend)

-  "Start delayed window autoselection.

-MOUSE-POSITION is the last position where the mouse was seen as returned

-by `mouse-position'.  Optional argument WINDOW non-nil denotes the

-window where the mouse was seen.  Optional argument SUSPEND non-nil

-means suspend autoselection."

-  ;; Record values for MOUSE-POSITION, WINDOW, and SUSPEND.

-  (setq mouse-autoselect-window-position mouse-position)

-  (when window (setq mouse-autoselect-window-window window))

-  (setq mouse-autoselect-window-state (when suspend 'suspend))

-  ;; Install timer which runs `mouse-autoselect-window-select' after

-  ;; `mouse-autoselect-window' seconds.

-  (setq mouse-autoselect-window-timer

-        (run-at-time

-         (abs mouse-autoselect-window) nil 'mouse-autoselect-window-select)))

-

-(defun mouse-autoselect-window-select ()

-  "Select window with delayed window autoselection.

-If the mouse position has stabilized in a non-selected window, select

-that window.  The minibuffer window is selected only if the minibuffer is

-active.  This function is run by `mouse-autoselect-window-timer'."

-  (condition-case nil

-      (let* ((mouse-position (mouse-position))

-             (window

-              (condition-case nil

-                  (window-at (cadr mouse-position) (cddr mouse-position)

-                             (car mouse-position))

-                (error nil))))

-        (cond

-         ((or (menu-or-popup-active-p)

-              (and window

-                   (not (coordinates-in-window-p (cdr mouse-position) window))))

-          ;; A menu / popup dialog is active or the mouse is on the scroll-bar

-          ;; of WINDOW, temporarily suspend delayed autoselection.

-          (mouse-autoselect-window-start mouse-position nil t))

-         ((eq mouse-autoselect-window-state 'suspend)

-          ;; Delayed autoselection was temporarily suspended, reenable it.

-          (mouse-autoselect-window-start mouse-position))

-         ((and window (not (eq window (selected-window)))

-               (or (not (numberp mouse-autoselect-window))

-                   (and (> mouse-autoselect-window 0)

-                        ;; If `mouse-autoselect-window' is positive, select

-                        ;; window if the window is the same as before.

-                        (eq window mouse-autoselect-window-window))

-                   ;; Otherwise select window if the mouse is at the same

-                   ;; position as before.  Observe that the first test after

-                   ;; starting autoselection usually fails since the value of

-                   ;; `mouse-autoselect-window-position' recorded there is the

-                   ;; position where the mouse has entered the new window and

-                   ;; not necessarily where the mouse has stopped moving.

-                   (equal mouse-position mouse-autoselect-window-position))

-               ;; The minibuffer is a candidate window if it's active.

-               (or (not (window-minibuffer-p window))

-                   (eq window (active-minibuffer-window))))

-          ;; Mouse position has stabilized in non-selected window: Cancel

-          ;; delayed autoselection and try to select that window.

-          (mouse-autoselect-window-cancel t)

-          ;; Select window where mouse appears unless the selected window is the

-          ;; minibuffer.  Use `unread-command-events' in order to execute pre-

-          ;; and post-command hooks and trigger idle timers.  To avoid delaying

-          ;; autoselection again, set `mouse-autoselect-window-state'."

-          (unless (window-minibuffer-p (selected-window))

-            (setq mouse-autoselect-window-state 'select)

-            (setq unread-command-events

-                  (cons (list 'select-window (list window))

-                        unread-command-events))))

-         ((or (and window (eq window (selected-window)))

-              (not (numberp mouse-autoselect-window))

-              (equal mouse-position mouse-autoselect-window-position))

-          ;; Mouse position has either stabilized in the selected window or at

-          ;; `mouse-autoselect-window-position': Cancel delayed autoselection.

-          (mouse-autoselect-window-cancel t))

-         (t

-          ;; Mouse position has not stabilized yet, resume delayed

-          ;; autoselection.

-          (mouse-autoselect-window-start mouse-position window))))

-    (error nil)))

-

-(defun handle-select-window (event)

-  "Handle select-window events."

-  (interactive "e")

-  (let ((window (posn-window (event-start event))))

-    (unless (or (not (window-live-p window))

-                ;; Don't switch if we're currently in the minibuffer.

-                ;; This tries to work around problems where the

-                ;; minibuffer gets unselected unexpectedly, and where

-                ;; you then have to move your mouse all the way down to

-                ;; the minibuffer to select it.

-                (window-minibuffer-p (selected-window))

-                ;; Don't switch to minibuffer window unless it's active.

-                (and (window-minibuffer-p window)

-                     (not (minibuffer-window-active-p window)))

-                ;; Don't switch when autoselection shall be delayed.

-                (and (numberp mouse-autoselect-window)

-                     (not (zerop mouse-autoselect-window))

-                     (not (eq mouse-autoselect-window-state 'select))

-                     (progn

-                       ;; Cancel any delayed autoselection.

-                       (mouse-autoselect-window-cancel t)

-                       ;; Start delayed autoselection from current mouse

-                       ;; position and window.

-                       (mouse-autoselect-window-start (mouse-position) window)

-                       ;; Executing a command cancels delayed autoselection.

-                       (add-hook

-                        'pre-command-hook 'mouse-autoselect-window-cancel))))

-      (when mouse-autoselect-window

-        ;; Reset state of delayed autoselection.

-        (setq mouse-autoselect-window-state nil)

-        ;; Run `mouse-leave-buffer-hook' when autoselecting window.

-        (run-hooks 'mouse-leave-buffer-hook))

-      (select-window window))))

-

-(defun delete-other-windows-vertically (&optional window)

-  "Delete the windows in the same column with WINDOW, but not WINDOW itself.

-This may be a useful alternative binding for \\[delete-other-windows]

- if you often split windows horizontally."

-  (interactive)

-  (let* ((window (or window (selected-window)))

-         (edges (window-edges window))

-         (w window) delenda)

-    (while (not (eq (setq w (next-window w 1)) window))

-      (let ((e (window-edges w)))

-        (when (and (= (car e) (car edges))

-                   (= (caddr e) (caddr edges)))

-          (push w delenda))))

-    (mapc 'delete-window delenda)))

-

-(defun truncated-partial-width-window-p (&optional window)

-  "Return non-nil if lines in WINDOW are specifically truncated due to its width.

-WINDOW defaults to the selected window.

-Return nil if WINDOW is not a partial-width window

- (regardless of the value of `truncate-lines').

-Otherwise, consult the value of `truncate-partial-width-windows'

- for the buffer shown in WINDOW."

-  (unless window

-    (setq window (selected-window)))

-  (unless (window-full-width-p window)

-    (let ((t-p-w-w (buffer-local-value 'truncate-partial-width-windows

-                                       (window-buffer window))))

-      (if (integerp t-p-w-w)

-          (< (window-width window) t-p-w-w)

-        t-p-w-w))))

-

-(define-key ctl-x-map "2" 'split-window-vertically)

-(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)

-

-;; arch-tag: b508dfcc-c353-4c37-89fa-e773fe10cea9

-;;; window.el ends here

+;;; window.el --- GNU Emacs window commands aside from those written in C
+
+;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001, 2002,
+;;   2003, 2004, 2005, 2006, 2007, 2008 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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Window tree functions.
+
+;;; Code:
+
+(eval-when-compile (require 'cl))
+
+(defvar window-size-fixed nil
+ "*Non-nil in a buffer means windows displaying the buffer are fixed-size.
+If the value is `height', then only the window's height is fixed.
+If the value is `width', then only the window's width is fixed.
+Any other non-nil value fixes both the width and the height.
+Emacs won't change the size of any window displaying that buffer,
+unless you explicitly change the size, or Emacs has no other choice.")
+(make-variable-buffer-local 'window-size-fixed)
+
+(defmacro save-selected-window (&rest body)
+  "Execute BODY, then select the previously selected window.
+The value returned is the value of the last form in BODY.
+
+This macro saves and restores the selected window, as well as the
+selected window in each frame.  If the previously selected window
+is no longer live, then whatever window is selected at the end of
+BODY remains selected.  If the previously selected window of some
+frame is no longer live at the end of BODY, that frame's selected
+window is left alone.
+
+This macro saves and restores the current buffer, since otherwise
+its normal operation could make a different buffer current.  The
+order of recently selected windows and the buffer list ordering
+are not altered by this macro (unless they are altered in BODY)."
+  `(let ((save-selected-window-window (selected-window))
+         ;; It is necessary to save all of these, because calling
+         ;; select-window changes frame-selected-window for whatever
+         ;; frame that window is in.
+         (save-selected-window-alist
+          (mapcar (lambda (frame) (cons frame (frame-selected-window frame)))
+                  (frame-list))))
+     (save-current-buffer
+       (unwind-protect
+           (progn ,@body)
+         (dolist (elt save-selected-window-alist)
+           (and (frame-live-p (car elt))
+                (window-live-p (cdr elt))
+                (set-frame-selected-window (car elt) (cdr elt) 'norecord)))
+         (when (window-live-p save-selected-window-window)
+           (select-window save-selected-window-window 'norecord))))))
+
+(defun window-body-height (&optional window)
+  "Return number of lines in WINDOW available for actual buffer text.
+WINDOW defaults to the selected window.
+
+The return value does not include the mode line or the header
+line, if any.  If a line at the bottom of the window is only
+partially visible, that line is included in the return value.  If
+you do not want to include a partially visible bottom line in the
+return value, use `window-text-height' instead."
+  (or window (setq window (selected-window)))
+  (if (window-minibuffer-p window)
+      (window-height window)
+    (with-current-buffer (window-buffer window)
+      (max 1 (- (window-height window)
+                (if mode-line-format 1 0)
+                (if header-line-format 1 0))))))
+
+(defun one-window-p (&optional nomini all-frames)
+  "Return non-nil if the selected window is the only window.
+Optional arg NOMINI non-nil means don't count the minibuffer
+even if it is active.  Otherwise, the minibuffer is counted
+when 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).
+ALL-FRAMES 0 means count all windows in all visible or iconified frames.
+If ALL-FRAMES is anything else, 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 window-current-scroll-bars (&optional window)
+  "Return the current scroll bar settings for WINDOW.
+WINDOW defaults to the selected window.
+
+The return value is a cons cell (VERTICAL . HORIZONTAL) where
+VERTICAL specifies the current location of the vertical scroll
+bars (`left', `right', or nil), and HORIZONTAL specifies the
+current location of the horizontal scroll bars (`top', `bottom',
+or nil).
+
+Unlike `window-scroll-bars', this function reports the scroll bar
+type actually used, once frame defaults and `scroll-bar-mode' are
+taken into account."
+  (let ((vert (nth 2 (window-scroll-bars window)))
+        (hor nil))
+    (when (or (eq vert t) (eq hor t))
+      (let ((fcsb (frame-current-scroll-bars
+                   (window-frame (or window (selected-window))))))
+        (if (eq vert t)
+            (setq vert (car fcsb)))
+        (if (eq hor t)
+            (setq hor (cdr fcsb)))))
+    (cons vert hor)))
+
+(defun walk-windows (proc &optional minibuf all-frames)
+  "Cycle through all windows, calling PROC for each one.
+PROC must specify a function with a window as its sole argument.
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to include in the walk, see also `next-window'.
+
+MINIBUF t means include the minibuffer window even if the
+minibuffer is not active.  MINIBUF nil or omitted means include
+the minibuffer window only if the minibuffer is active.  Any
+other value means do not include the minibuffer window even if
+the minibuffer is active.
+
+Several frames may share a single minibuffer; if the minibuffer
+is active, all windows on all frames that share that minibuffer
+are included 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 nil or omitted means cycle through all windows on
+ WINDOW's frame, plus the minibuffer window if specified by the
+ MINIBUF argument, see above.  If the minibuffer counts, cycle
+ through all windows on all frames that share that minibuffer
+ too.
+ALL-FRAMES t means cycle through all windows on all existing
+ frames.
+ALL-FRAMES `visible' means cycle through all windows on all
+ visible frames.
+ALL-FRAMES 0 means cycle through all windows on all visible and
+ iconified frames.
+ALL-FRAMES a frame means cycle through all windows on that frame
+ only.
+Anything else means cycle through all windows on WINDOW's frame
+ and no others.
+
+This function changes neither the order of recently selected
+windows nor the buffer list."
+  ;; If we start from the minibuffer window, don't fail to come
+  ;; back to it.
+  (when (window-minibuffer-p (selected-window))
+    (setq minibuf t))
+  ;; Make sure to not mess up the order of recently selected
+  ;; windows.  Use `save-selected-window' and `select-window'
+  ;; with second argument non-nil for this purpose.
+  (save-selected-window
+    (when (framep all-frames)
+      (select-window (frame-first-window all-frames) 'norecord))
+    (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.
+More precisely, cycle through all windows using `walk-windows',
+calling the function PREDICATE on each one of them with the
+window as its sole argument.  Return the first window for which
+PREDICATE returns non-nil.  If no window satisfies PREDICATE,
+return DEFAULT.
+
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to include.  See `walk-windows' for the meaning of these
+arguments."
+  (catch 'found
+    (walk-windows #'(lambda (window)
+                      (when (funcall predicate window)
+                        (throw 'found window)))
+                  minibuf all-frames)
+    default))
+
+(defalias 'some-window 'get-window-with-predicate)
+
+;; This should probably be written in C (i.e., without using `walk-windows').
+(defun get-buffer-window-list (&optional buffer-or-name minibuf all-frames)
+  "Return list of all windows displaying BUFFER-OR-NAME, or nil if none.
+BUFFER-OR-NAME may be a buffer or the name of an existing buffer
+and defaults to the current buffer.
+
+The optional arguments MINIBUF and ALL-FRAMES specify the set of
+windows to consider.  See `walk-windows' for the precise meaning
+of these arguments."
+  (let ((buffer (cond
+                 ((not buffer-or-name) (current-buffer))
+                 ((bufferp buffer-or-name) buffer-or-name)
+                 (t (get-buffer buffer-or-name))))
+        windows)
+    (walk-windows (function (lambda (window)
+                              (if (eq (window-buffer window) buffer)
+                                  (setq windows (cons window windows)))))
+                  minibuf all-frames)
+    windows))
+
+(defun minibuffer-window-active-p (window)
+  "Return t if WINDOW is the currently active minibuffer window."
+  (eq window (active-minibuffer-window)))
+
+(defun count-windows (&optional minibuf)
+   "Return the number of visible windows.
+The optional argument MINIBUF specifies whether the minibuffer
+window shall be counted.  See `walk-windows' for the precise
+meaning of this argument."
+   (let ((count 0))
+     (walk-windows (lambda (w) (setq count (+ count 1)))
+                   minibuf)
+     count))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;; `balance-windows' subroutines using `window-tree'
+
+;;; Translate from internal window tree format
+
+(defun bw-get-tree (&optional window-or-frame)
+  "Get a window split tree in our format.
+
+WINDOW-OR-FRAME must be nil, a frame, or a window.  If it is nil,
+then the whole window split tree for `selected-frame' is returned.
+If it is a frame, then this is used instead.  If it is a window,
+then the smallest tree containing that window is returned."
+  (when window-or-frame
+    (unless (or (framep window-or-frame)
+                (windowp window-or-frame))
+      (error "Not a frame or window: %s" window-or-frame)))
+  (let ((subtree (bw-find-tree-sub window-or-frame)))
+    (when subtree
+      (if (integerp subtree)
+          nil
+        (bw-get-tree-1 subtree)))))
+
+(defun bw-get-tree-1 (split)
+  (if (windowp split)
+      split
+    (let ((dir (car split))
+          (edges (car (cdr split)))
+          (childs (cdr (cdr split))))
+      (list
+       (cons 'dir (if dir 'ver 'hor))
+       (cons 'b (nth 3 edges))
+       (cons 'r (nth 2 edges))
+       (cons 't (nth 1 edges))
+       (cons 'l (nth 0 edges))
+       (cons 'childs (mapcar #'bw-get-tree-1 childs))))))
+
+(defun bw-find-tree-sub (window-or-frame &optional get-parent)
+  (let* ((window (when (windowp window-or-frame) window-or-frame))
+         (frame (when (windowp window) (window-frame window)))
+         (wt (car (window-tree frame))))
+    (when (< 1 (length (window-list frame 0)))
+      (if window
+          (bw-find-tree-sub-1 wt window get-parent)
+        wt))))
+
+(defun bw-find-tree-sub-1 (tree win &optional get-parent)
+  (unless (windowp win) (error "Not a window: %s" win))
+  (if (memq win tree)
+      (if get-parent
+          get-parent
+        tree)
+    (let ((childs (cdr (cdr tree)))
+          child
+          subtree)
+      (while (and childs (not subtree))
+        (setq child (car childs))
+        (setq childs (cdr childs))
+        (when (and child (listp child))
+          (setq subtree (bw-find-tree-sub-1 child win get-parent))))
+      (if (integerp subtree)
+          (progn
+            (if (= 1 subtree)
+                tree
+              (1- subtree)))
+        subtree
+        ))))
+
+;;; Window or object edges
+
+(defun bw-l (obj)
+  "Left edge of OBJ."
+  (if (windowp obj) (nth 0 (window-edges obj)) (cdr (assq 'l obj))))
+(defun bw-t (obj)
+  "Top edge of OBJ."
+  (if (windowp obj) (nth 1 (window-edges obj)) (cdr (assq 't obj))))
+(defun bw-r (obj)
+  "Right edge of OBJ."
+  (if (windowp obj) (nth 2 (window-edges obj)) (cdr (assq 'r obj))))
+(defun bw-b (obj)
+  "Bottom edge of OBJ."
+  (if (windowp obj) (nth 3 (window-edges obj)) (cdr (assq 'b obj))))
+
+;;; Split directions
+
+(defun bw-dir (obj)
+  "Return window split tree direction if OBJ.
+If OBJ is a window return 'both.  If it is a window split tree
+then return its direction."
+  (if (symbolp obj)
+      obj
+    (if (windowp obj)
+        'both
+      (let ((dir (cdr (assq 'dir obj))))
+        (unless (memq dir '(hor ver both))
+          (error "Can't find dir in %s" obj))
+        dir))))
+
+(defun bw-eqdir (obj1 obj2)
+  "Return t if window split tree directions are equal.
+OBJ1 and OBJ2 should be either windows or window split trees in
+our format.  The directions returned by `bw-dir' are compared and
+t is returned if they are `eq' or one of them is 'both."
+  (let ((dir1 (bw-dir obj1))
+        (dir2 (bw-dir obj2)))
+    (or (eq dir1 dir2)
+        (eq dir1 'both)
+        (eq dir2 'both))))
+
+;;; Building split tree
+
+(defun bw-refresh-edges (obj)
+  "Refresh the edge information of OBJ and return OBJ."
+  (unless (windowp obj)
+    (let ((childs (cdr (assq 'childs obj)))
+          (ol 1000)
+          (ot 1000)
+          (or -1)
+          (ob -1))
+      (dolist (o childs)
+        (when (> ol (bw-l o)) (setq ol (bw-l o)))
+        (when (> ot (bw-t o)) (setq ot (bw-t o)))
+        (when (< or (bw-r o)) (setq or (bw-r o)))
+        (when (< ob (bw-b o)) (setq ob (bw-b o))))
+      (setq obj (delq 'l obj))
+      (setq obj (delq 't obj))
+      (setq obj (delq 'r obj))
+      (setq obj (delq 'b obj))
+      (add-to-list 'obj (cons 'l ol))
+      (add-to-list 'obj (cons 't ot))
+      (add-to-list 'obj (cons 'r or))
+      (add-to-list 'obj (cons 'b ob))
+      ))
+  obj)
+
+;;; Balance windows
+
+(defun balance-windows (&optional window-or-frame)
+  "Make windows the same heights or widths in window split subtrees.
+
+When called non-interactively WINDOW-OR-FRAME may be either a
+window or a frame.  It then balances the windows on the implied
+frame.  If the parameter is a window only the corresponding window
+subtree is balanced."
+  (interactive)
+  (let (
+        (wt (bw-get-tree window-or-frame))
+        (w)
+        (h)
+        (tried-sizes)
+        (last-sizes)
+        (windows (window-list nil 0)))
+    (when wt
+      (while (not (member last-sizes tried-sizes))
+        (when last-sizes (setq tried-sizes (cons last-sizes tried-sizes)))
+        (setq last-sizes (mapcar (lambda (w)
+                                   (window-edges w))
+                                 windows))
+        (when (eq 'hor (bw-dir wt))
+          (setq w (- (bw-r wt) (bw-l wt))))
+        (when (eq 'ver (bw-dir wt))
+          (setq h (- (bw-b wt) (bw-t wt))))
+        (bw-balance-sub wt w h)))))
+
+(defun bw-adjust-window (window delta horizontal)
+  "Wrapper around `adjust-window-trailing-edge' with error checking.
+Arguments WINDOW, DELTA and HORIZONTAL are passed on to that function."
+  ;; `adjust-window-trailing-edge' may fail if delta is too large.
+  (while (>= (abs delta) 1)
+    (condition-case err
+        (progn
+          (adjust-window-trailing-edge window delta horizontal)
+          (setq delta 0))
+      (error
+       ;;(message "adjust: %s" (error-message-string err))
+       (setq delta (/ delta 2))))))
+
+(defun bw-balance-sub (wt w h)
+  (setq wt (bw-refresh-edges wt))
+  (unless w (setq w (- (bw-r wt) (bw-l wt))))
+  (unless h (setq h (- (bw-b wt) (bw-t wt))))
+  (if (windowp wt)
+      (progn
+        (when w
+          (let ((dw (- w (- (bw-r wt) (bw-l wt)))))
+            (when (/= 0 dw)
+              (bw-adjust-window wt dw t))))
+        (when h
+          (let ((dh (- h (- (bw-b wt) (bw-t wt)))))
+            (when (/= 0 dh)
+              (bw-adjust-window wt dh nil)))))
+    (let* ((childs (cdr (assq 'childs wt)))
+           (cw (when w (/ w (if (bw-eqdir 'hor wt) (length childs) 1))))
+           (ch (when h (/ h (if (bw-eqdir 'ver wt) (length childs) 1)))))
+      (dolist (c childs)
+        (bw-balance-sub c cw ch)))))
+
+(defun window-fixed-size-p (&optional window direction)
+  "Return t if WINDOW cannot be resized in DIRECTION.
+WINDOW defaults to the selected window.  DIRECTION can be
+nil (i.e. any), `height' or `width'."
+  (with-current-buffer (window-buffer window)
+    (when (and (boundp 'window-size-fixed) window-size-fixed)
+      (not (and direction
+                (member (cons direction window-size-fixed)
+                        '((height . width) (width . height))))))))
+
+;;; A different solution to balance-windows.
+
+(defvar window-area-factor 1
+  "Factor by which the window area should be over-estimated.
+This is used by `balance-windows-area'.
+Changing this globally has no effect.")
+(make-variable-buffer-local 'window-area-factor)
+
+(defun balance-windows-area ()
+  "Make all visible windows the same area (approximately).
+See also `window-area-factor' to change the relative size of
+specific buffers."
+  (interactive)
+  (let* ((unchanged 0) (carry 0) (round 0)
+         ;; Remove fixed-size windows.
+         (wins (delq nil (mapcar (lambda (win)
+                                   (if (not (window-fixed-size-p win)) win))
+                                 (window-list nil 'nomini))))
+         (changelog nil)
+         next)
+    ;; Resizing a window changes the size of surrounding windows in complex
+    ;; ways, so it's difficult to balance them all.  The introduction of
+    ;; `adjust-window-trailing-edge' made it a bit easier, but it is still
+    ;; very difficult to do.  `balance-window' above takes an off-line
+    ;; approach: get the whole window tree, then balance it, then try to
+    ;; adjust the windows so they fit the result.
+    ;; Here, instead, we take a "local optimization" approach, where we just
+    ;; go through all the windows several times until nothing needs to be
+    ;; changed.  The main problem with this approach is that it's difficult
+    ;; to make sure it terminates, so we use some heuristic to try and break
+    ;; off infinite loops.
+    ;; After a round without any change, we allow a second, to give a chance
+    ;; to the carry to propagate a minor imbalance from the end back to
+    ;; the beginning.
+    (while (< unchanged 2)
+      ;; (message "New round")
+      (setq unchanged (1+ unchanged) round (1+ round))
+      (dolist (win wins)
+        (setq next win)
+        (while (progn (setq next (next-window next))
+                      (window-fixed-size-p next)))
+        ;; (assert (eq next (or (cadr (member win wins)) (car wins))))
+        (let* ((horiz
+                (< (car (window-edges win)) (car (window-edges next))))
+               (areadiff (/ (- (* (window-height next) (window-width next)
+                                  (buffer-local-value 'window-area-factor
+                                                      (window-buffer next)))
+                               (* (window-height win) (window-width win)
+                                  (buffer-local-value 'window-area-factor
+                                                      (window-buffer win))))
+                            (max (buffer-local-value 'window-area-factor
+                                                     (window-buffer win))
+                                 (buffer-local-value 'window-area-factor
+                                                     (window-buffer next)))))
+               (edgesize (if horiz
+                             (+ (window-height win) (window-height next))
+                           (+ (window-width win) (window-width next))))
+               (diff (/ areadiff edgesize)))
+          (when (zerop diff)
+            ;; Maybe diff is actually closer to 1 than to 0.
+            (setq diff (/ (* 3 areadiff) (* 2 edgesize))))
+          (when (and (zerop diff) (not (zerop areadiff)))
+            (setq diff (/ (+ areadiff carry) edgesize))
+            ;; Change things smoothly.
+            (if (or (> diff 1) (< diff -1)) (setq diff (/ diff 2))))
+          (if (zerop diff)
+              ;; Make sure negligible differences don't accumulate to
+              ;; become significant.
+              (setq carry (+ carry areadiff))
+            (bw-adjust-window win diff horiz)
+            ;; (sit-for 0.5)
+            (let ((change (cons win (window-edges win))))
+              ;; If the same change has been seen already for this window,
+              ;; we're most likely in an endless loop, so don't count it as
+              ;; a change.
+              (unless (member change changelog)
+                (push change changelog)
+                (setq unchanged 0 carry 0)))))))
+    ;; We've now basically balanced all the windows.
+    ;; But there may be some minor off-by-one imbalance left over,
+    ;; so let's do some fine tuning.
+    ;; (bw-finetune wins)
+    ;; (message "Done in %d rounds" round)
+    ))
+
+
+(defcustom display-buffer-function nil
+  "If non-nil, function to call to handle `display-buffer'.
+It will receive two args, the buffer and a flag which if non-nil
+means that the currently selected window is not acceptable.  It
+should choose or create a window, display the specified buffer in
+it, and return the window.
+
+Commands such as `switch-to-buffer-other-window' and
+`find-file-other-window' work using this function."
+  :type '(choice
+          (const nil)
+          (function :tag "function"))
+  :group 'windows)
+
+(defun special-display-p (buffer-name)
+  "Return non-nil if a buffer named BUFFER-NAME gets a special frame.
+If the value is t, `display-buffer' or `pop-to-buffer' would
+create a special frame for that buffer using the default frame
+parameters.
+
+If the value is a list, it is a list of frame parameters that
+would be used to make a frame for that buffer.  The variables
+`special-display-buffer-names' and `special-display-regexps'
+control this."
+  (let (tmp)
+  (cond
+   ((not (stringp buffer-name)))
+   ;; Make sure to return t in the following two cases.
+   ((member buffer-name special-display-buffer-names) t)
+     ((setq tmp (assoc buffer-name special-display-buffer-names)) (cdr tmp))
+   ((catch 'found
+      (dolist (regexp special-display-regexps)
+        (cond
+         ((stringp regexp)
+          (when (string-match-p regexp buffer-name)
+            (throw 'found t)))
+         ((and (consp regexp) (stringp (car regexp))
+               (string-match-p (car regexp) buffer-name))
+            (throw 'found (cdr regexp))))))))))
+
+(defcustom special-display-buffer-names nil
+  "List of buffer names that should have their own special frames.
+Displaying a buffer with `display-buffer' or `pop-to-buffer', if
+its name is in this list, makes a special frame for it using
+`special-display-function'.  See also `special-display-regexps'.
+
+An element of the list can be a list instead of just a string.
+There are two ways to use a list as an element:
+  (BUFFER FRAME-PARAMETERS...)  (BUFFER FUNCTION OTHER-ARGS...)
+In the first case, the FRAME-PARAMETERS are pairs of the form
+\(PARAMETER . VALUE); these parameter values are used to create
+the frame.  In the second case, FUNCTION is called with BUFFER as
+the first argument, followed by the OTHER-ARGS--it can display
+BUFFER in any way it likes.  All this is done by the function
+found in `special-display-function'.
+
+If the specified frame parameters include (same-buffer . t), the
+buffer is displayed in the currently selected window.  Otherwise, if
+they include (same-frame . t), the buffer is displayed in a new window
+in the currently selected frame.
+
+If this variable appears \"not to work\", because you add a name to it
+but that buffer still appears in the selected window, look at the
+values of `same-window-buffer-names' and `same-window-regexps'.
+Those variables take precedence over this one."
+  :type '(repeat (choice :tag "Buffer"
+                         :value ""
+                         (string :format "%v")
+                         (cons :tag "With attributes"
+                               :format "%v"
+                               :value ("" . nil)
+                               (string :format "%v")
+                               (repeat :tag "Attributes"
+                                       (cons :format "%v"
+                                             (symbol :tag "Parameter")
+                                             (sexp :tag "Value"))))))
+  :group 'frames)
+
+(defcustom special-display-regexps nil
+  "List of regexps saying which buffers should have their own special frames.
+When displaying a buffer with `display-buffer' or
+`pop-to-buffer', if any regexp in this list matches the buffer
+name, it makes a special frame for the buffer by calling
+`special-display-function'.
+
+An element of the list can be a list instead of just a string.
+There are two ways to use a list as an element:
+  (REGEXP FRAME-PARAMETERS...)  (REGEXP FUNCTION OTHER-ARGS...)
+In the first case, the FRAME-PARAMETERS are pairs of the form
+\(PARAMETER . VALUE); these parameter values are used to create
+the frame.  In the second case, FUNCTION is called with BUFFER as
+the first argument, followed by the OTHER-ARGS--it can display
+the buffer in any way it likes.  All this is done by the function
+found in `special-display-function'.
+
+If the specified frame parameters include (same-buffer . t), the
+buffer is displayed in the currently selected window.  Otherwise,
+if they include (same-frame . t), the buffer is displayed in a
+new window in the currently selected frame.
+
+If this variable appears \"not to work\", because you add a
+regexp to it but the matching buffers still appear in the
+selected window, look at the values of `same-window-buffer-names'
+and `same-window-regexps'.  Those variables take precedence over
+this one."
+  :type '(repeat (choice :tag "Buffer"
+                         :value ""
+                         (regexp :format "%v")
+                         (cons :tag "With attributes"
+                               :format "%v"
+                               :value ("" . nil)
+                               (regexp :format "%v")
+                               (repeat :tag "Attributes"
+                                       (cons :format "%v"
+                                             (symbol :tag "Parameter")
+                                             (sexp :tag "Value"))))))
+  :group 'frames)
+
+(defcustom special-display-function 'special-display-popup-frame
+  "Function to call to make a new frame for a special buffer.
+It is called with two arguments, the buffer and optional buffer
+specific data, and should return a window displaying that buffer.
+The default value normally makes a separate frame for the buffer,
+using `special-display-frame-alist' to specify the frame
+parameters.
+
+But if the buffer specific data includes (same-buffer . t) then
+the buffer is displayed in the current selected window.
+Otherwise if it includes (same-frame . t) then the buffer is
+displayed in a new window in the currently selected frame.
+
+A buffer is special if it is listed in
+`special-display-buffer-names' or matches a regexp in
+`special-display-regexps'."
+  :type 'function
+  :group 'frames)
+
+(defun same-window-p (buffer-name)
+  "Return non-nil if a buffer named BUFFER-NAME would be shown in the \"same\" window.
+This function returns non-nil if `display-buffer' or
+`pop-to-buffer' would show a buffer named BUFFER-NAME in the
+selected rather than \(as usual\) some other window.  See
+`same-window-buffer-names' and `same-window-regexps'."
+  (cond
+   ((not (stringp buffer-name)))
+   ;; The elements of `same-window-buffer-names' can be buffer
+   ;; names or cons cells whose cars are buffer names.
+   ((member buffer-name same-window-buffer-names))
+   ((assoc buffer-name same-window-buffer-names))
+   ((catch 'found
+      (dolist (regexp same-window-regexps)
+        ;; The elements of `same-window-regexps' can be regexps
+        ;; or cons cells whose cars are regexps.
+        (when (or (and (stringp regexp)
+                       (string-match regexp buffer-name))
+                  (and (consp regexp) (stringp (car regexp))
+                       (string-match-p (car regexp) buffer-name)))
+          (throw 'found t)))))))
+
+(defcustom same-window-buffer-names nil
+  "List of names of buffers that should appear in the \"same\" window.
+`display-buffer' and `pop-to-buffer' show a buffer whose name is
+on this list in the selected rather than some other window.
+
+An element of this list can be a cons cell instead of just a
+string.  In that case the car must be a string specifying the
+buffer name.  This is for compatibility with
+`special-display-buffer-names'; the cdr of the cons cell is
+ignored.
+
+See also `same-window-regexps'."
+ :type '(repeat (string :format "%v"))
+ :group 'windows)
+
+(defcustom same-window-regexps nil
+  "List of regexps saying which buffers should appear in the \"same\" window.
+`display-buffer' and `pop-to-buffer' show a buffer whose name
+matches a regexp on this list in the selected rather than some
+other window.
+
+An element of this list can be a cons cell instead of just a
+string.  In that case the car must be a string, which specifies
+the buffer name.  This is for compatibility with
+`special-display-buffer-names'; the cdr of the cons cell is
+ignored.
+
+See also `same-window-buffer-names'."
+  :type '(repeat (regexp :format "%v"))
+  :group 'windows)
+
+(defcustom pop-up-frames nil
+  "Whether `display-buffer' should make a separate frame.
+If nil, never make a seperate frame.
+If the value is `graphic-only', make a separate frame
+on graphic displays only.
+Any other non-nil value means always make a separate frame."
+  :type '(choice
+          (const :tag "Never" nil)
+          (const :tag "On graphic displays only" graphic-only)
+          (const :tag "Always" t))
+  :group 'windows)
+
+(defcustom display-buffer-reuse-frames nil
+  "Non-nil means `display-buffer' should reuse frames.
+If the buffer in question is already displayed in a frame, raise
+that frame."
+  :type 'boolean
+  :version "21.1"
+  :group 'windows)
+
+(defcustom pop-up-windows t
+  "Non-nil means `display-buffer' should make a new window."
+  :type 'boolean
+  :group 'windows)
+
+(defcustom split-height-threshold 80
+  "Minimum height of window to be split vertically.
+If the value is a number, `display-buffer' can split a window
+only if it has at least as many lines.  If the value is nil,
+`display-buffer' cannot split a window vertically.
+
+If the window is the only window on its frame, `display-buffer'
+can split it regardless of this value."
+  :type '(choice (const nil) (number :tag "lines"))
+  :version "23.1"
+  :group 'windows)
+
+(defcustom split-width-threshold 160
+  "Minimum width of window to be split horizontally.
+If the value is a number, `display-buffer' can split a window
+only if it has at least as many columns.  If the value is nil,
+`display-buffer' cannot split a window horizontally."
+  :type '(choice (const nil) (number :tag "columns"))
+  :version "23.1"
+  :group 'windows)
+
+(defcustom split-window-preferred-function nil
+  "Function used by `display-buffer' to split windows.
+If non-nil, a function called with a window as single argument
+supposed to split that window and return the new window.  If the
+function returns nil the window is not split.
+
+If nil, `display-buffer' will split the window respecting the
+values of `split-height-threshold' and `split-width-threshold'."
+  :type '(choice (const nil) (function :tag "Function"))
+  :version "23.1"
+  :group 'windows)
+
+(defun window--splittable-p (window &optional horizontal)
+  "Return non-nil if WINDOW can be split evenly.
+Optional argument HORIZONTAL non-nil means check whether WINDOW
+can be split horizontally.
+
+WINDOW can be split vertically when the following conditions
+hold:
+
+- `window-size-fixed' is either nil or equals `width' for the
+  buffer of WINDOW.
+
+- `split-height-threshold' is a number and WINDOW is at least as
+  high as `split-height-threshold'.
+
+- When WINDOW is split evenly, the emanating windows are at least
+  `window-min-height' lines tall and can accommodate at least one
+  line plus - if WINDOW has one - a mode line.
+
+WINDOW can be split horizontally when the following conditions
+hold:
+
+- `window-size-fixed' is either nil or equals `height' for the
+  buffer of WINDOW.
+
+- `split-width-threshold' is a number and WINDOW is at least as
+  wide as `split-width-threshold'.
+
+- When WINDOW is split evenly, the emanating windows are at least
+  `window-min-width' or two (whichever is larger) columns wide."
+  (when (window-live-p window)
+    (with-current-buffer (window-buffer window)
+      (if horizontal
+          ;; A window can be split horizontally when its width is not
+          ;; fixed, it is at least `split-width-threshold' columns wide
+          ;; and at least twice as wide as `window-min-width' and 2 (the
+          ;; latter value is hardcoded).
+          (and (memq window-size-fixed '(nil height))
+               ;; Testing `window-full-width-p' here hardly makes any
+               ;; sense nowadays.  This can be done more intuitively by
+               ;; setting up `split-width-threshold' appropriately.
+               (numberp split-width-threshold)
+               (>= (window-width window)
+                   (max split-width-threshold
+                        (* 2 (max window-min-width 2)))))
+        ;; A window can be split vertically when its height is not
+        ;; fixed, it is at least `split-height-threshold' lines high,
+        ;; and it is at least twice as high as `window-min-height' and 2
+        ;; if it has a modeline or 1.
+        (and (memq window-size-fixed '(nil width))
+             (numberp split-height-threshold)
+             (>= (window-height window)
+                 (max split-height-threshold
+                      (* 2 (max window-min-height
+                                (if mode-line-format 2 1))))))))))
+
+(defun window--try-to-split-window (window)
+  "Split WINDOW if it is splittable.
+See `window--splittable-p' for how to determine whether a window
+is splittable.  If WINDOW can be split, return the value returned
+by `split-window' (or `split-window-preferred-function')."
+  (when (and (window-live-p window)
+             (not (frame-parameter (window-frame window) 'unsplittable)))
+    (if (functionp split-window-preferred-function)
+        ;; `split-window-preferred-function' is specified, so use it.
+        (funcall split-window-preferred-function window)
+      (or (and (window--splittable-p window)
+               ;; Split window vertically.
+               (split-window window))
+          (and (window--splittable-p window t)
+               ;; Split window horizontally.
+               (split-window window nil t))
+          (and (eq window (frame-root-window (window-frame window)))
+               (not (window-minibuffer-p window))
+               ;; If WINDOW is the only window on its frame and not the
+               ;; minibuffer window, attempt to split it vertically
+               ;; disregarding the value of `split-height-threshold'.
+               (let ((split-height-threshold 0))
+                 (and (window--splittable-p window)
+                      (split-window window))))))))
+
+(defun window--frame-usable-p (frame)
+  "Return FRAME if it can be used to display a buffer."
+  (when (frame-live-p frame)
+    (let ((window (frame-root-window frame)))
+      ;; `frame-root-window' may be an internal window which is considered
+      ;; "dead" by `window-live-p'.  Hence if `window' is not live we
+      ;; implicitly know that `frame' has a visible window we can use.
+      (when (or (not (window-live-p window))
+                (and (not (window-minibuffer-p window))
+                     (not (window-dedicated-p window))))
+        frame))))
+
+(defcustom even-window-heights t
+  "If non-nil `display-buffer' will try to even window heights.
+Otherwise `display-buffer' will leave the window configuration
+alone.  Heights are evened only when `display-buffer' chooses a
+window that appears above or below the selected window."
+  :type 'boolean
+  :group 'windows)
+
+(defun window--even-window-heights (window)
+  "Even heights of WINDOW and selected window.
+Do this only if these windows are vertically adjacent to each
+other, `even-window-heights' is non-nil, and the selected window
+is higher than WINDOW."
+  (when (and even-window-heights
+             (not (eq window (selected-window)))
+             ;; Don't resize minibuffer windows.
+             (not (window-minibuffer-p (selected-window)))
+             (> (window-height (selected-window)) (window-height window)) 
+             (eq (window-frame window) (window-frame (selected-window)))
+             (let ((sel-edges (window-edges (selected-window)))
+                   (win-edges (window-edges window)))
+               (and (= (nth 0 sel-edges) (nth 0 win-edges))
+                    (= (nth 2 sel-edges) (nth 2 win-edges))
+                    (or (= (nth 1 sel-edges) (nth 3 win-edges))
+                        (= (nth 3 sel-edges) (nth 1 win-edges))))))
+    (let ((window-min-height 1))
+      ;; Don't throw an error if we can't even window heights for
+      ;; whatever reason.
+      (condition-case nil
+          (enlarge-window (/ (- (window-height window) (window-height)) 2))
+        (error nil)))))
+
+(defun window--display-buffer-1 (window)
+  "Raise the frame containing WINDOW.
+Do not raise the selected frame.  Return WINDOW."
+  (let* ((frame (window-frame window))
+         (visible (frame-visible-p frame)))
+    (unless (or (not visible)
+                ;; Assume the selected frame is already visible enough.
+                (eq frame (selected-frame))
+                ;; Assume the frame from which we invoked the minibuffer
+                ;; is visible.
+                (and (minibuffer-window-active-p (selected-window))
+                     (eq frame (window-frame (minibuffer-selected-window)))))
+      (raise-frame frame))
+    window))
+
+(defun window--display-buffer-2 (buffer window)
+  "Display BUFFER in WINDOW and make its frame visible.
+Return WINDOW."
+  (when (and (buffer-live-p buffer) (window-live-p window))
+    (set-window-buffer window buffer)
+    (window--display-buffer-1 window)))
+
+(defun display-buffer (buffer-or-name &optional not-this-window frame)
+  "Make buffer BUFFER-OR-NAME appear in some window but don't select it.
+BUFFER-OR-NAME must be a buffer or the name of an existing
+buffer.  Return the window chosen to display BUFFER-OR-NAME or
+nil if no such window is found.
+
+Optional argument NOT-THIS-WINDOW non-nil means display the
+buffer in a window other than the selected one, even if it is
+already displayed in the selected window.
+
+Optional argument FRAME specifies which frames to investigate
+when the specified buffer is already displayed.  If the buffer is
+already displayed in some window on one of these frames simply
+return that window.  Possible values of FRAME are:
+
+`visible' - consider windows on all visible frames.
+
+0 - consider windows on all visible or iconified frames.
+
+t - consider windows on all frames.
+
+A specific frame - consider windows on that frame only.
+
+nil - consider windows on the selected frame \(actually the
+last non-minibuffer frame\) only.  If, however, either
+`display-buffer-reuse-frames' or `pop-up-frames' is non-nil
+\(non-nil and not graphic-only on a text-only terminal),
+consider all visible or iconified frames."
+  (interactive "BDisplay buffer:\nP")
+  (let* ((can-use-selected-window
+          ;; The selected window is usable unless either NOT-THIS-WINDOW
+          ;; is non-nil, it is dedicated to its buffer, or it is the
+          ;; `minibuffer-window'.
+          (not (or not-this-window
+                   (window-dedicated-p (selected-window))
+                   (window-minibuffer-p))))
+         (buffer (if (bufferp buffer-or-name)
+                     buffer-or-name
+                   (get-buffer buffer-or-name)))
+         (name-of-buffer (buffer-name buffer))
+         ;; On text-only terminals do not pop up a new frame when
+         ;; `pop-up-frames' equals graphic-only.
+         (use-pop-up-frames (if (eq pop-up-frames 'graphic-only)
+                                (display-graphic-p)
+                              pop-up-frames))
+         ;; `frame-to-use' is the frame where to show `buffer' - either
+         ;; the selected frame or the last nonminibuffer frame.
+         (frame-to-use
+          (or (window--frame-usable-p (selected-frame))
+              (window--frame-usable-p (last-nonminibuffer-frame))))
+         ;; `window-to-use' is the window we use for showing `buffer'.
+         window-to-use)
+    (cond
+     ((not (buffer-live-p buffer))
+      (error "No such buffer %s" buffer))
+     (display-buffer-function
+      ;; Let `display-buffer-function' do the job.
+      (funcall display-buffer-function buffer not-this-window))
+     ((and (not not-this-window)
+           (eq (window-buffer (selected-window)) buffer))
+      ;; The selected window already displays BUFFER and
+      ;; `not-this-window' is nil, so use it.
+      (window--display-buffer-1 (selected-window)))
+     ((and can-use-selected-window (same-window-p name-of-buffer))
+      ;; If the buffer's name tells us to use the selected window do so.
+      (window--display-buffer-2 buffer (selected-window)))
+     ((let ((frames (or frame
+                        (and (or use-pop-up-frames
+                                 display-buffer-reuse-frames
+                                 (not (last-nonminibuffer-frame)))
+                             0)
+                        (last-nonminibuffer-frame))))
+        (and (setq window-to-use (get-buffer-window buffer frames))
+             (or can-use-selected-window
+                 (not (eq (selected-window) window-to-use)))))
+      ;; If the buffer is already displayed in some window use that.
+      (window--display-buffer-1 window-to-use))
+     ((and special-display-function
+           ;; `special-display-p' returns either t or a list of frame
+           ;; parameters to pass to `special-display-function'.
+           (let ((pars (special-display-p name-of-buffer)))
+             (when pars
+               (funcall special-display-function
+                        buffer (if (listp pars) pars))))))
+     ((or use-pop-up-frames (not frame-to-use))
+      ;; We want or need a new frame.
+      (window--display-buffer-2
+       buffer (frame-selected-window (funcall pop-up-frame-function))))
+     ((and pop-up-windows
+           ;; Make a new window.
+           (or (not (frame-parameter frame-to-use 'unsplittable))
+               ;; If the selected frame cannot be split look at
+               ;; `last-nonminibuffer-frame'.
+               (and (eq frame-to-use (selected-frame))
+                    (setq frame-to-use (last-nonminibuffer-frame))
+                    (window--frame-usable-p frame-to-use)
+                    (not (frame-parameter frame-to-use 'unsplittable))))
+           ;; Attempt to split largest or least recently used window.
+           (setq window-to-use
+                 (or (window--try-to-split-window
+                      (get-largest-window frame-to-use t))
+                     (window--try-to-split-window
+                      (get-lru-window frame-to-use t))))
+           (window--display-buffer-2 buffer window-to-use)))
+     ((setq window-to-use
+            ;; Reuse an existing window.
+            (or (get-lru-window frame-to-use)
+                (get-buffer-window buffer 'visible)
+                (get-largest-window 'visible nil)
+                (get-buffer-window buffer 0)
+                (get-largest-window 0 nil)
+                (frame-selected-window (funcall pop-up-frame-function))))
+      (window--even-window-heights window-to-use)
+      (window--display-buffer-2 buffer window-to-use)))))
+
+(defun pop-to-buffer (buffer-or-name &optional other-window norecord)
+  "Select buffer BUFFER-OR-NAME in some window, preferably a different one.
+BUFFER-OR-NAME may be a buffer, a string \(a buffer name), or
+nil.  If BUFFER-OR-NAME is a string not naming an existent
+buffer, create a buffer with that name.  If BUFFER-OR-NAME is
+nil, choose some other buffer.
+
+If `pop-up-windows' is non-nil, windows can be split to display
+the buffer.  If optional second arg OTHER-WINDOW is non-nil,
+insist on finding another window even if the specified buffer is
+already visible in the selected window, and ignore
+`same-window-regexps' and `same-window-buffer-names'.
+
+If the window to show BUFFER-OR-NAME is not on the selected
+frame, raise that window's frame and give it input focus.
+
+This function returns the buffer it switched to.  This uses the
+function `display-buffer' as a subroutine; see the documentation
+of `display-buffer' for additional customization information.
+
+Optional third arg NORECORD non-nil means do not put this buffer
+at the front of the list of recently selected ones."
+  (let ((buffer
+         ;; FIXME: This behavior is carried over from the previous C version
+         ;; of pop-to-buffer, but really we should use just
+         ;; `get-buffer' here.
+         (if (null buffer-or-name) (other-buffer (current-buffer))
+           (or (get-buffer buffer-or-name)
+               (let ((buf (get-buffer-create buffer-or-name)))
+                 (set-buffer-major-mode buf)
+                 buf))))
+        (old-window (selected-window))
+        (old-frame (selected-frame))
+        new-window new-frame)
+    (set-buffer buffer)
+    (setq new-window (display-buffer buffer other-window))
+    (unless (eq new-window old-window)
+      ;; `display-buffer' has chosen another window, select it.
+      (select-window new-window norecord)
+      (setq new-frame (window-frame new-window))
+      (unless (eq new-frame old-frame)
+        ;; `display-buffer' has chosen another frame, make sure it gets
+        ;; input focus and is risen.
+        (select-frame-set-input-focus new-frame)))
+    buffer))
+
+;; I think this should be the default; I think people will prefer it--rms.
+(defcustom split-window-keep-point t
+  "If non-nil, \\[split-window-vertically] 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.
+
+This option applies only to `split-window-vertically' and
+functions that call it.  `split-window' always keeps the original
+point in both children."
+  :type 'boolean
+  :group 'windows)
+
+(defun split-window-vertically (&optional size)
+  "Split selected window into two windows, one above the other.
+The upper window gets SIZE lines and the lower one gets the rest.
+SIZE negative means the lower window gets -SIZE lines and the
+upper one the rest.  With no argument, split windows 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 will get the same value of point as the selected window.
+This is often more convenient for editing.  The upper window is
+the selected window.
+
+Otherwise, we choose 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.
+
+Regardless of the value of `split-window-keep-point', the upper
+window is the original one and the return value is the new, lower
+window."
+  (interactive "P")
+  (let ((old-window (selected-window))
+        (old-point (point))
+        (size (and size (prefix-numeric-value size)))
+        moved-by-window-height moved new-window bottom)
+    (and size (< size 0)
+         ;; Handle negative SIZE value.
+         (setq size (+ (window-height) size)))
+    (setq new-window (split-window nil size))
+    (unless split-window-keep-point
+      (save-excursion
+        (set-buffer (window-buffer))
+        (goto-char (window-start))
+        (setq moved (vertical-motion (window-height)))
+        (set-window-start new-window (point))
+        (when (> (point) (window-point new-window))
+          (set-window-point new-window (point)))
+        (when (= moved (window-height))
+          (setq moved-by-window-height t)
+          (vertical-motion -1))
+        (setq bottom (point)))
+      (and moved-by-window-height
+           (<= bottom (point))
+           (set-window-point old-window (1- bottom)))
+      (and moved-by-window-height
+           (<= (window-start new-window) old-point)
+           (set-window-point new-window old-point)
+           (select-window new-window)))
+    (split-window-save-restore-data new-window old-window)))
+
+;; This is to avoid compiler warnings.
+(defvar view-return-to-alist)
+
+(defun split-window-save-restore-data (new-window old-window)
+  (with-current-buffer (window-buffer)
+    (when view-mode
+      (let ((old-info (assq old-window view-return-to-alist)))
+        (when old-info
+          (push (cons new-window (cons (car (cdr old-info)) t))
+                view-return-to-alist))))
+    new-window))
+
+(defun split-window-horizontally (&optional size)
+  "Split selected window into two windows side by side.
+The selected window becomes the left one and gets SIZE columns.
+SIZE negative means the right window gets -SIZE lines.
+
+SIZE 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.  SIZE omitted or nil means split
+window equally.
+
+The selected window remains selected.  Return the new window."
+  (interactive "P")
+  (let ((old-window (selected-window))
+        (size (and size (prefix-numeric-value size))))
+    (and size (< size 0)
+         ;; Handle negative SIZE value.
+         (setq size (+ (window-width) size)))
+    (split-window-save-restore-data (split-window nil size t) old-window)))
+
+
+(defun set-window-text-height (window height)
+  "Sets the height in lines of the text display area of WINDOW to HEIGHT.
+HEIGHT doesn't include the mode line or header line, if any, or
+any partial-height lines in the text display area.
+
+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)
+      ;; Setting window-min-height to a value like 1 can lead to very
+      ;; bizarre displays because it also allows Emacs to make *other*
+      ;; windows 1-line tall, which means that there's no more space for
+      ;; the modeline.
+      (let ((window-min-height (min 2 height))) ; One text line plus a modeline.
+        (if (and window (not (eq window (selected-window))))
+            (save-selected-window
+              (select-window window 'norecord)
+              (enlarge-window delta))
+          (enlarge-window delta))))))
+
+
+(defun enlarge-window-horizontally (columns)
+  "Make selected window COLUMNS wider.
+Interactively, if no argument is given, make selected window one
+column wider."
+  (interactive "p")
+  (enlarge-window columns t))
+
+(defun shrink-window-horizontally (columns)
+  "Make selected window COLUMNS narrower.
+Interactively, if no argument is given, make selected window one
+column narrower."
+  (interactive "p")
+  (shrink-window columns t))
+
+(defun window-buffer-height (window)
+  "Return the height (in screen lines) of the buffer that WINDOW is displaying."
+  (with-current-buffer (window-buffer window)
+    (max 1
+         (count-screen-lines (point-min) (point-max)
+                             ;; If buffer ends with a newline, ignore it when
+                             ;; counting height unless point is after it.
+                             (eobp)
+                             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)
+  "Adjust height of WINDOW to display its buffer's contents exactly.
+WINDOW defaults to the selected window.
+Optional argument MAX-HEIGHT specifies the maximum height of the
+window and defaults to the height of WINDOW's frame.
+Optional argument MIN-HEIGHT specifies the minimum height of the
+window and defaults to `window-min-height'.
+Both, MAX-HEIGHT and MIN-HEIGHT are specified in lines and
+include the mode line and header line, if any.
+Always return nil."
+  (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)))
+
+    ;; 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 'norecord)
+
+      ;; 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 window-safely-shrinkable-p (&optional window)
+  "Return t if WINDOW can be shrunk without shrinking other windows.
+WINDOW defaults to the selected window."
+  (with-selected-window (or window (selected-window))
+    (let ((edges (window-edges)))
+      (or (= (nth 2 edges) (nth 2 (window-edges (previous-window))))
+          (= (nth 0 edges) (nth 0 (window-edges (next-window))))))))
+
+(defun shrink-window-if-larger-than-buffer (&optional window)
+  "Shrink height of WINDOW if its buffer doesn't need so many lines.
+More precisely, shrink WINDOW vertically to be as small as
+possible, while still showing the full contents of its buffer.
+WINDOW 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, nil otherwise."
+  (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 window)
+             (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)
+  (let ((window-to-delete (selected-window))
+        (buffer-to-kill (current-buffer))
+        (delete-window-hook (lambda ()
+                              (condition-case nil
+                                  (delete-window)
+                                (error nil)))))
+    (unwind-protect
+        (progn
+          (add-hook 'kill-buffer-hook delete-window-hook t t)
+          (if (kill-buffer (current-buffer))
+              ;; If `delete-window' failed before, we rerun it to regenerate
+              ;; the error so it can be seen in the echo area.
+              (when (eq (selected-window) window-to-delete)
+                (delete-window))))
+      ;; If the buffer is not dead for some reason (probably because
+      ;; of a `quit' signal), remove the hook again.
+      (condition-case nil
+          (with-current-buffer buffer-to-kill
+            (remove-hook 'kill-buffer-hook delete-window-hook t))
+        (error nil)))))
+
+(defun quit-window (&optional kill window)
+  "Quit WINDOW and bury its buffer.
+With a prefix argument, kill the buffer instead.  WINDOW defaults
+to the selected window.
+
+If WINDOW is non-nil, dedicated, or a minibuffer window, delete
+it and, if it's alone on its frame, its frame too.  Otherwise, or
+if deleting WINDOW fails in any of the preceding cases, display
+another buffer in WINDOW using `switch-to-buffer'.
+
+Optional argument KILL non-nil means kill WINDOW's buffer.
+Otherwise, bury WINDOW's buffer, see `bury-buffer'."
+  (interactive "P")
+  (let ((buffer (window-buffer window)))
+    (if (or window
+            (window-minibuffer-p window)
+            (window-dedicated-p window))
+        ;; WINDOW is either non-nil, a minibuffer window, or dedicated;
+        ;; try to delete it.
+        (let ((frame (window-frame (or window (selected-window)))))
+          (if (eq window (frame-root-window frame))
+              ;; WINDOW is alone on its frame.  `delete-windows-on'
+              ;; knows how to handle that case.
+              (delete-windows-on buffer frame)
+            ;; There are other windows on its frame, delete WINDOW.
+            (delete-window window)))
+      ;; Otherwise, switch to another buffer in the selected window.
+      (switch-to-buffer nil))
+
+    ;; Deal with the buffer.
+    (if kill
+        (kill-buffer buffer)
+      (bury-buffer buffer))))
+
+(defvar recenter-last-op nil
+  "Indicates the last recenter operation performed.
+Possible values: `top', `middle', `bottom'.")
+
+(defun recenter-top-bottom (&optional arg)
+  "Move current line to window center, top, and bottom, successively.
+With no prefix argument, the first call redraws the frame and
+ centers point vertically within the window.  Successive calls
+ scroll the window, placing point on the top, bottom, and middle
+ consecutively.  The cycling order is middle -> top -> bottom.
+
+A prefix argument is handled like `recenter':
+ With numeric prefix ARG, move current line to window-line ARG.
+ With plain `C-u', move current line to window center.
+
+Top and bottom destinations are actually `scroll-margin' lines
+ the from true window top and bottom."
+  (interactive "P")
+  (cond
+   (arg (recenter arg))                 ; Always respect ARG.
+   ((or (not (eq this-command last-command))
+        (eq recenter-last-op 'bottom))
+    (setq recenter-last-op 'middle)
+    (recenter))
+   (t
+    (let ((this-scroll-margin
+           (min (max 0 scroll-margin)
+                (truncate (/ (window-body-height) 4.0)))))
+      (cond ((eq recenter-last-op 'middle)
+             (setq recenter-last-op 'top)
+             (recenter this-scroll-margin))
+            ((eq recenter-last-op 'top)
+             (setq recenter-last-op 'bottom)
+             (recenter (- -1 this-scroll-margin))))))))
+
+(define-key global-map [?\C-l] 'recenter-top-bottom)
+
+(defvar mouse-autoselect-window-timer nil
+  "Timer used by delayed window autoselection.")
+
+(defvar mouse-autoselect-window-position nil
+  "Last mouse position recorded by delayed window autoselection.")
+
+(defvar mouse-autoselect-window-window nil
+  "Last window recorded by delayed window autoselection.")
+
+(defvar mouse-autoselect-window-state nil
+  "When non-nil, special state of delayed window autoselection.
+Possible values are `suspend' \(suspend autoselection after a menu or
+scrollbar interaction\) and `select' \(the next invocation of
+'handle-select-window' shall select the window immediately\).")
+
+(defun mouse-autoselect-window-cancel (&optional force)
+  "Cancel delayed window autoselection.
+Optional argument FORCE means cancel unconditionally."
+  (unless (and (not force)
+               ;; Don't cancel for select-window or select-frame events
+               ;; or when the user drags a scroll bar.
+               (or (memq this-command
+                         '(handle-select-window handle-switch-frame))
+                   (and (eq this-command 'scroll-bar-toolkit-scroll)
+                        (memq (nth 4 (event-end last-input-event))
+                              '(handle end-scroll)))))
+    (setq mouse-autoselect-window-state nil)
+    (when (timerp mouse-autoselect-window-timer)
+      (cancel-timer mouse-autoselect-window-timer))
+    (remove-hook 'pre-command-hook 'mouse-autoselect-window-cancel)))
+
+(defun mouse-autoselect-window-start (mouse-position &optional window suspend)
+  "Start delayed window autoselection.
+MOUSE-POSITION is the last position where the mouse was seen as returned
+by `mouse-position'.  Optional argument WINDOW non-nil denotes the
+window where the mouse was seen.  Optional argument SUSPEND non-nil
+means suspend autoselection."
+  ;; Record values for MOUSE-POSITION, WINDOW, and SUSPEND.
+  (setq mouse-autoselect-window-position mouse-position)
+  (when window (setq mouse-autoselect-window-window window))
+  (setq mouse-autoselect-window-state (when suspend 'suspend))
+  ;; Install timer which runs `mouse-autoselect-window-select' after
+  ;; `mouse-autoselect-window' seconds.
+  (setq mouse-autoselect-window-timer
+        (run-at-time
+         (abs mouse-autoselect-window) nil 'mouse-autoselect-window-select)))
+
+(defun mouse-autoselect-window-select ()
+  "Select window with delayed window autoselection.
+If the mouse position has stabilized in a non-selected window, select
+that window.  The minibuffer window is selected only if the minibuffer is
+active.  This function is run by `mouse-autoselect-window-timer'."
+  (condition-case nil
+      (let* ((mouse-position (mouse-position))
+             (window
+              (condition-case nil
+                  (window-at (cadr mouse-position) (cddr mouse-position)
+                             (car mouse-position))
+                (error nil))))
+        (cond
+         ((or (menu-or-popup-active-p)
+              (and window
+                   (not (coordinates-in-window-p (cdr mouse-position) window))))
+          ;; A menu / popup dialog is active or the mouse is on the scroll-bar
+          ;; of WINDOW, temporarily suspend delayed autoselection.
+          (mouse-autoselect-window-start mouse-position nil t))
+         ((eq mouse-autoselect-window-state 'suspend)
+          ;; Delayed autoselection was temporarily suspended, reenable it.
+          (mouse-autoselect-window-start mouse-position))
+         ((and window (not (eq window (selected-window)))
+               (or (not (numberp mouse-autoselect-window))
+                   (and (> mouse-autoselect-window 0)
+                        ;; If `mouse-autoselect-window' is positive, select
+                        ;; window if the window is the same as before.
+                        (eq window mouse-autoselect-window-window))
+                   ;; Otherwise select window if the mouse is at the same
+                   ;; position as before.  Observe that the first test after
+                   ;; starting autoselection usually fails since the value of
+                   ;; `mouse-autoselect-window-position' recorded there is the
+                   ;; position where the mouse has entered the new window and
+                   ;; not necessarily where the mouse has stopped moving.
+                   (equal mouse-position mouse-autoselect-window-position))
+               ;; The minibuffer is a candidate window if it's active.
+               (or (not (window-minibuffer-p window))
+                   (eq window (active-minibuffer-window))))
+          ;; Mouse position has stabilized in non-selected window: Cancel
+          ;; delayed autoselection and try to select that window.
+          (mouse-autoselect-window-cancel t)
+          ;; Select window where mouse appears unless the selected window is the
+          ;; minibuffer.  Use `unread-command-events' in order to execute pre-
+          ;; and post-command hooks and trigger idle timers.  To avoid delaying
+          ;; autoselection again, set `mouse-autoselect-window-state'."
+          (unless (window-minibuffer-p (selected-window))
+            (setq mouse-autoselect-window-state 'select)
+            (setq unread-command-events
+                  (cons (list 'select-window (list window))
+                        unread-command-events))))
+         ((or (and window (eq window (selected-window)))
+              (not (numberp mouse-autoselect-window))
+              (equal mouse-position mouse-autoselect-window-position))
+          ;; Mouse position has either stabilized in the selected window or at
+          ;; `mouse-autoselect-window-position': Cancel delayed autoselection.
+          (mouse-autoselect-window-cancel t))
+         (t
+          ;; Mouse position has not stabilized yet, resume delayed
+          ;; autoselection.
+          (mouse-autoselect-window-start mouse-position window))))
+    (error nil)))
+
+(defun handle-select-window (event)
+  "Handle select-window events."
+  (interactive "e")
+  (let ((window (posn-window (event-start event))))
+    (unless (or (not (window-live-p window))
+                ;; Don't switch if we're currently in the minibuffer.
+                ;; This tries to work around problems where the
+                ;; minibuffer gets unselected unexpectedly, and where
+                ;; you then have to move your mouse all the way down to
+                ;; the minibuffer to select it.
+                (window-minibuffer-p (selected-window))
+                ;; Don't switch to minibuffer window unless it's active.
+                (and (window-minibuffer-p window)
+                     (not (minibuffer-window-active-p window)))
+                ;; Don't switch when autoselection shall be delayed.
+                (and (numberp mouse-autoselect-window)
+                     (not (zerop mouse-autoselect-window))
+                     (not (eq mouse-autoselect-window-state 'select))
+                     (progn
+                       ;; Cancel any delayed autoselection.
+                       (mouse-autoselect-window-cancel t)
+                       ;; Start delayed autoselection from current mouse
+                       ;; position and window.
+                       (mouse-autoselect-window-start (mouse-position) window)
+                       ;; Executing a command cancels delayed autoselection.
+                       (add-hook
+                        'pre-command-hook 'mouse-autoselect-window-cancel))))
+      (when mouse-autoselect-window
+        ;; Reset state of delayed autoselection.
+        (setq mouse-autoselect-window-state nil)
+        ;; Run `mouse-leave-buffer-hook' when autoselecting window.
+        (run-hooks 'mouse-leave-buffer-hook))
+      (select-window window))))
+
+(defun delete-other-windows-vertically (&optional window)
+  "Delete the windows in the same column with WINDOW, but not WINDOW itself.
+This may be a useful alternative binding for \\[delete-other-windows]
+ if you often split windows horizontally."
+  (interactive)
+  (let* ((window (or window (selected-window)))
+         (edges (window-edges window))
+         (w window) delenda)
+    (while (not (eq (setq w (next-window w 1)) window))
+      (let ((e (window-edges w)))
+        (when (and (= (car e) (car edges))
+                   (= (caddr e) (caddr edges)))
+          (push w delenda))))
+    (mapc 'delete-window delenda)))
+
+(defun truncated-partial-width-window-p (&optional window)
+  "Return non-nil if lines in WINDOW are specifically truncated due to its width.
+WINDOW defaults to the selected window.
+Return nil if WINDOW is not a partial-width window
+ (regardless of the value of `truncate-lines').
+Otherwise, consult the value of `truncate-partial-width-windows'
+ for the buffer shown in WINDOW."
+  (unless window
+    (setq window (selected-window)))
+  (unless (window-full-width-p window)
+    (let ((t-p-w-w (buffer-local-value 'truncate-partial-width-windows
+                                       (window-buffer window))))
+      (if (integerp t-p-w-w)
+          (< (window-width window) t-p-w-w)
+        t-p-w-w))))
+
+(define-key ctl-x-map "2" 'split-window-vertically)
+(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)
+
+;; arch-tag: b508dfcc-c353-4c37-89fa-e773fe10cea9
+;;; window.el ends here