*** empty log message ***

2 files changed, 1633 insertions, 1629 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 90aa1e14a45..8a9364ae40c 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2008-09-10  Martin Rudalics  <rudalics@gmx.at>
+
+        * window.el (display-buffer): Fix doc-string typo.
+
 2008-09-10  Kenichi Handa  <handa@m17n.org>
 
         * composite.el (compose-gstring-for-graphic): Fix previous change.
diff --git a/lisp/window.el b/lisp/window.el
index a15d785ff6c..5875a5ba8e8 100644
--- a/lisp/window.el
+++ b/lisp/window.el
@@ -1,1629 +1,1629 @@
-;;; 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 window that was selected before BODY.
-The value returned is the value of the last form in BODY.
-
-This macro saves and restores the current buffer, since otherwise
-its normal operation could potentially make a different
-buffer current.  It does not alter the buffer list ordering.
-
-This macro saves and restores the selected window, as well as
-the selected window in each frame.  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.  If the selected window is
-no longer live, then whatever window is selected at the end of
-BODY remains selected."
-  `(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))))
-         (if (window-live-p save-selected-window-window)
-             (select-window save-selected-window-window))))))
-
-(defun window-body-height (&optional window)
-  "Return number of lines in window WINDOW for actual buffer text.
-This does not include the mode line (if any) or the header line (if any)."
-  (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 in window WINDOW.
-Value is a cons (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)."
-  (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 visible windows, calling PROC for each one.
-PROC is called with a window as argument.
-
-Optional second arg MINIBUF t means count the minibuffer window even
-if not active.  MINIBUF nil or omitted means count the minibuffer only if
-it is active.  MINIBUF neither t nor nil means not to count the
-minibuffer even if it is active.
-
-Several frames may share a single minibuffer; if the minibuffer
-counts, all windows on all frames that share that minibuffer count
-too.  Therefore, if you are using a separate minibuffer frame
-and the minibuffer is active and MINIBUF says it counts,
-`walk-windows' includes the windows in the frame from which you
-entered the minibuffer, as well as the minibuffer window.
-
-ALL-FRAMES is the optional third argument.
-ALL-FRAMES nil or omitted means cycle within the frames as specified above.
-ALL-FRAMES = `visible' means include windows on all visible frames.
-ALL-FRAMES = 0 means include windows on all visible and iconified frames.
-ALL-FRAMES = t means include windows on all frames including invisible frames.
-If ALL-FRAMES is a frame, it means include windows on that frame.
-Anything else means restrict to the selected frame."
-  ;; If we start from the minibuffer window, don't fail to come back to it.
-  (if (window-minibuffer-p (selected-window))
-      (setq minibuf t))
-  (save-selected-window
-    (if (framep all-frames)
-        (select-window (frame-first-window all-frames)))
-    (let* (walk-windows-already-seen
-           (walk-windows-current (selected-window)))
-      (while (progn
-               (setq walk-windows-current
-                     (next-window walk-windows-current minibuf all-frames))
-               (not (memq walk-windows-current walk-windows-already-seen)))
-        (setq walk-windows-already-seen
-              (cons walk-windows-current walk-windows-already-seen))
-        (funcall proc walk-windows-current)))))
-
-(defun get-window-with-predicate (predicate &optional minibuf
-                                            all-frames default)
-  "Return a window satisfying PREDICATE.
-
-This function cycles through all visible windows using `walk-windows',
-calling PREDICATE on each one.  PREDICATE is called with a window as
-argument.  The first window for which PREDICATE returns a non-nil
-value is returned.  If no window satisfies PREDICATE, DEFAULT is
-returned.
-
-Optional second arg MINIBUF t means count the minibuffer window even
-if not active.  MINIBUF nil or omitted means count the minibuffer only if
-it is active.  MINIBUF neither t nor nil means not to count the
-minibuffer even if it is active.
-
-Several frames may share a single minibuffer; if the minibuffer
-counts, all windows on all frames that share that minibuffer count
-too.  Therefore, if you are using a separate minibuffer frame
-and the minibuffer is active and MINIBUF says it counts,
-`walk-windows' includes the windows in the frame from which you
-entered the minibuffer, as well as the minibuffer window.
-
-ALL-FRAMES is the optional third argument.
-ALL-FRAMES nil or omitted means cycle within the frames as specified above.
-ALL-FRAMES = `visible' means include windows on all visible frames.
-ALL-FRAMES = 0 means include windows on all visible and iconified frames.
-ALL-FRAMES = t means include windows on all frames including invisible frames.
-If ALL-FRAMES is a frame, it means include windows on that frame.
-Anything else means restrict to the selected frame."
-  (catch 'found
-    (walk-windows #'(lambda (window)
-                      (when (funcall predicate window)
-                        (throw 'found window)))
-                  minibuf all-frames)
-    default))
-
-(defalias 'some-window 'get-window-with-predicate)
-
-;; This should probably be written in C (i.e., without using `walk-windows').
-(defun get-buffer-window-list (buffer &optional minibuf all-frames)
-  "Return list of all windows displaying BUFFER, or nil if none.
-BUFFER can be a buffer or a buffer name.
-See `walk-windows' for the meaning of MINIBUF and ALL-FRAMES."
-  (let ((buffer (if (bufferp buffer) buffer (get-buffer buffer))) 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 (a minibuffer window) is now active."
-  (eq window (active-minibuffer-window)))
-
-(defun count-windows (&optional minibuf)
-   "Return the number of visible windows.
-This counts the windows in the selected frame and (if the minibuffer is
-to be counted) its minibuffer frame (if that's not the same frame).
-The optional arg MINIBUF non-nil means count the minibuffer
-even if it is inactive."
-   (let ((count 0))
-     (walk-windows (lambda (w) (setq count (+ count 1)))
-                   minibuf)
-     count))
-
-(defun window-safely-shrinkable-p (&optional window)
-  "Non-nil if the WINDOW can be shrunk without shrinking other windows.
-If WINDOW is nil or omitted, it defaults to the currently selected window."
-  (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))))))))
-
-
-;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-;;; `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)))))
-
-;;; A different solution to balance-windows
-
-(defun window-fixed-size-p (&optional window direction)
-  "Non-nil if WINDOW cannot be resized in DIRECTION.
-DIRECTION can be nil (i.e. any), `height' or `width'."
-  (with-current-buffer (window-buffer window)
-    (let ((fixed (and (boundp 'window-size-fixed) window-size-fixed)))
-      (when fixed
-        (not (and direction
-                  (member (cons direction window-size-fixed)
-                          '((height . width) (width . height)))))))))
-
-(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
-  "Non-nil means `display-buffer' should make a separate frame."
-  :type 'boolean
-  :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 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 modeline.
-
-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 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 FRAME if it can be used to display another buffer."
-  (when (framep 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 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)
-  "Deiconify the frame containing the window WINDOW.
-Do not deiconify 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)))))
-      (when (eq visible 'icon)
-        (make-frame-visible frame))
-      (raise-frame frame))
-    window))
-
-(defun window--display-buffer-2 (buffer window)
-  "Display buffer BUFFER in window 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 is 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,
-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))
-         ;; `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 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 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'.
-
-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)))))
-    (set-buffer buffer)
-    (select-window (display-buffer buffer other-window) norecord)
-    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 arg)
-  "Split current window into two windows, one above the other.
-The uppermost window gets ARG lines and the other gets the rest.
-Negative ARG means select the size of the lowermost window instead.
-With no argument, split equally or close to it.
-Both windows display the same buffer now current.
-
-If the variable `split-window-keep-point' is non-nil, both new windows
-will get the same value of point as the current 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-w (selected-window))
-        (old-point (point))
-        (size (and arg (prefix-numeric-value arg)))
-        (window-full-p nil)
-        new-w bottom moved)
-    (and size (< size 0) (setq size (+ (window-height) size)))
-    (setq new-w (split-window nil size))
-    (or split-window-keep-point
-        (progn
-          (save-excursion
-            (set-buffer (window-buffer))
-            (goto-char (window-start))
-            (setq moved (vertical-motion (window-height)))
-            (set-window-start new-w (point))
-            (if (> (point) (window-point new-w))
-                (set-window-point new-w (point)))
-            (and (= moved (window-height))
-                 (progn
-                   (setq window-full-p t)
-                   (vertical-motion -1)))
-            (setq bottom (point)))
-          (and window-full-p
-               (<= bottom (point))
-               (set-window-point old-w (1- bottom)))
-          (and window-full-p
-               (<= (window-start new-w) old-point)
-               (progn
-                 (set-window-point new-w old-point)
-                 (select-window new-w)))))
-    (split-window-save-restore-data new-w old-w)))
-
-;; This is to avoid compiler warnings.
-(defvar view-return-to-alist)
-
-(defun split-window-save-restore-data (new-w old-w)
-  (with-current-buffer (window-buffer)
-    (if view-mode
-        (let ((old-info (assq old-w view-return-to-alist)))
-          (if old-info
-              (push (cons new-w (cons (car (cdr old-info)) t))
-                    view-return-to-alist))))
-    new-w))
-
-(defun split-window-horizontally (&optional arg)
-  "Split current window into two windows side by side.
-This window becomes the leftmost of the two, and gets ARG columns.
-Negative ARG means select the size of the rightmost window instead.
-The argument includes the width of the window's scroll bar; if there
-are no scroll bars, it includes the width of the divider column
-to the window's right, if any.  No ARG means split equally.
-
-The original, leftmost window remains selected.
-The return value is the new, rightmost window."
-  (interactive "P")
-  (let ((old-w (selected-window))
-        (size (and arg (prefix-numeric-value arg))))
-    (and size (< size 0)
-         (setq size (+ (window-width) size)))
-    (split-window-save-restore-data (split-window nil size t) old-w)))
-
-
-(defun set-window-text-height (window height)
-  "Sets the height in lines of the text display area of WINDOW to HEIGHT.
-This doesn't include the mode-line (or header-line if any) or any
-partial-height lines in the text display area.
-
-If WINDOW is nil, the selected window is used.
-
-Note that the current implementation of this function cannot always set
-the height exactly, but attempts to be conservative, by allocating more
-lines than are actually needed in the case where some error may be present."
-  (let ((delta (- height (window-text-height window))))
-    (unless (zerop delta)
-      ;; 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)
-              (enlarge-window delta))
-          (enlarge-window delta))))))
-
-
-(defun enlarge-window-horizontally (arg)
-  "Make current window ARG columns wider."
-  (interactive "p")
-  (enlarge-window arg t))
-
-(defun shrink-window-horizontally (arg)
-  "Make current window ARG columns narrower."
-  (interactive "p")
-  (shrink-window arg 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)
-  "Make WINDOW the right height to display its contents exactly.
-If WINDOW is omitted or nil, it defaults to the selected window.
-If the optional argument MAX-HEIGHT is supplied, it is the maximum height
-  the window is allowed to be, defaulting to the frame height.
-If the optional argument MIN-HEIGHT is supplied, it is the minimum
-  height the window is allowed to be, defaulting to `window-min-height'.
-
-The heights in MAX-HEIGHT and MIN-HEIGHT include the mode-line and/or
-header-line."
-  (interactive)
-
-  (when (null window)
-    (setq window (selected-window)))
-  (when (null max-height)
-    (setq max-height (frame-height (window-frame window))))
-
-  (let* ((buf
-          ;; Buffer that is displayed in WINDOW
-          (window-buffer window))
-         (window-height
-          ;; The current height of WINDOW
-          (window-height window))
-         (desired-height
-          ;; The height necessary to show the buffer displayed by WINDOW
-          ;; (`count-screen-lines' always works on the current buffer).
-          (with-current-buffer buf
-            (+ (count-screen-lines)
-               ;; If the buffer is empty, (count-screen-lines) is
-               ;; zero.  But, even in that case, we need one text line
-               ;; for cursor.
-               (if (= (point-min) (point-max))
-                   1 0)
-               ;; For non-minibuffers, count the mode-line, if any
-               (if (and (not (window-minibuffer-p window))
-                        mode-line-format)
-                   1 0)
-               ;; Count the header-line, if any
-               (if header-line-format 1 0))))
-         (delta
-          ;; Calculate how much the window height has to change to show
-          ;; desired-height lines, constrained by MIN-HEIGHT and MAX-HEIGHT.
-          (- (max (min desired-height max-height)
-                  (or min-height window-min-height))
-             window-height)))
-
-    ;; Don't try to redisplay with the cursor at the end
-    ;; on its own line--that would force a scroll and spoil things.
-    (when (with-current-buffer buf
-            (and (eobp) (bolp) (not (bobp))))
-      (set-window-point window (1- (window-point window))))
-
-    (save-selected-window
-      (select-window window)
-
-      ;; Adjust WINDOW to the nominally correct size (which may actually
-      ;; be slightly off because of variable height text, etc).
-      (unless (zerop delta)
-        (enlarge-window delta))
-
-      ;; Check if the last line is surely fully visible.  If not,
-      ;; enlarge the window.
-      (let ((end (with-current-buffer buf
-                   (save-excursion
-                     (goto-char (point-max))
-                     (when (and (bolp) (not (bobp)))
-                       ;; Don't include final newline
-                       (backward-char 1))
-                     (when truncate-lines
-                       ;; If line-wrapping is turned off, test the
-                       ;; beginning of the last line for visibility
-                       ;; instead of the end, as the end of the line
-                       ;; could be invisible by virtue of extending past
-                       ;; the edge of the window.
-                       (forward-line 0))
-                     (point)))))
-        (set-window-vscroll window 0)
-        (while (and (< desired-height max-height)
-                    (= desired-height (window-height window))
-                    (not (pos-visible-in-window-p end window)))
-          (enlarge-window 1)
-          (setq desired-height (1+ desired-height)))))))
-
-(defun shrink-window-if-larger-than-buffer (&optional window)
-  "Shrink the WINDOW to be as small as possible to display its contents.
-If WINDOW is omitted or nil, it defaults to the selected window.
-Do not shrink to less than `window-min-height' lines.
-Do nothing if the buffer contains more lines than the present window height,
-or if some of the window's contents are scrolled out of view,
-or if shrinking this window would also shrink another window,
-or if the window is the only window of its frame."
-  (interactive)
-  (when (null window)
-    (setq window (selected-window)))
-  (let* ((frame (window-frame window))
-         (mini (frame-parameter frame 'minibuffer))
-         (edges (window-edges window)))
-    (if (and (not (eq window (frame-root-window frame)))
-             (window-safely-shrinkable-p)
-             (pos-visible-in-window-p (point-min) window)
-             (not (eq mini 'only))
-             (or (not mini)
-                 (let ((mini-window (minibuffer-window frame)))
-                   (or (null mini-window)
-                       (not (eq frame (window-frame mini-window)))
-                       (< (nth 3 edges)
-                          (nth 1 (window-edges mini-window)))
-                       (> (nth 1 edges)
-                          (frame-parameter frame 'menu-bar-lines))))))
-        (fit-window-to-buffer window (window-height window)))))
-
-(defun kill-buffer-and-window ()
-  "Kill the current buffer and delete the selected window."
-  (interactive)
-  (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 the current buffer.  Bury it, and maybe delete the selected frame.
-\(The frame is deleted if it contains a dedicated window for the buffer.)
-With a prefix argument, kill the buffer instead.
-
-Noninteractively, if KILL is non-nil, then kill the current buffer,
-otherwise bury it.
-
-If WINDOW is non-nil, it specifies a window; we delete that window,
-and the buffer that is killed or buried is the one in that window."
-  (interactive "P")
-  (let ((buffer (window-buffer window))
-        (frame (window-frame (or window (selected-window))))
-        (window-solitary
-         (save-selected-window
-           (if window
-               (select-window window))
-           (one-window-p t)))
-        window-handled)
-
-    (save-selected-window
-      (if window
-          (select-window window))
-      (or (window-minibuffer-p)
-          (window-dedicated-p (selected-window))
-          (switch-to-buffer (other-buffer))))
-
-    ;; Get rid of the frame, if it has just one dedicated window
-    ;; and other visible frames exist.
-    (and (or (window-minibuffer-p) (window-dedicated-p window))
-         (delq frame (visible-frame-list))
-         window-solitary
-         (if (and (eq default-minibuffer-frame frame)
-                  (= 1 (length (minibuffer-frame-list))))
-             (setq window nil)
-           (delete-frame frame)
-           (setq window-handled t)))
-
-    ;; Deal with the buffer.
-    (if kill
-        (kill-buffer buffer)
-      (bury-buffer buffer))
-
-    ;; Maybe get rid of the window.
-    (and window (not window-handled) (not window-solitary)
-         (delete-window window))))
-
-(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)
-  "Non-nil if lines in WINDOW are specifically truncated due to its width.
-This returns 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.
-If WINDOW is nil, use the selected 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 window that was selected before BODY.

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

+

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

+its normal operation could potentially make a different

+buffer current.  It does not alter the buffer list ordering.

+

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

+the selected window in each frame.  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.  If the selected window is

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

+BODY remains selected."

+  `(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))))

+         (if (window-live-p save-selected-window-window)

+             (select-window save-selected-window-window))))))

+

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

+  "Return number of lines in window WINDOW for actual buffer text.

+This does not include the mode line (if any) or the header line (if any)."

+  (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 in window WINDOW.

+Value is a cons (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)."

+  (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 visible windows, calling PROC for each one.

+PROC is called with a window as argument.

+

+Optional second arg MINIBUF t means count the minibuffer window even

+if not active.  MINIBUF nil or omitted means count the minibuffer only if

+it is active.  MINIBUF neither t nor nil means not to count the

+minibuffer even if it is active.

+

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

+counts, all windows on all frames that share that minibuffer count

+too.  Therefore, if you are using a separate minibuffer frame

+and the minibuffer is active and MINIBUF says it counts,

+`walk-windows' includes the windows in the frame from which you

+entered the minibuffer, as well as the minibuffer window.

+

+ALL-FRAMES is the optional third argument.

+ALL-FRAMES nil or omitted means cycle within the frames as specified above.

+ALL-FRAMES = `visible' means include windows on all visible frames.

+ALL-FRAMES = 0 means include windows on all visible and iconified frames.

+ALL-FRAMES = t means include windows on all frames including invisible frames.

+If ALL-FRAMES is a frame, it means include windows on that frame.

+Anything else means restrict to the selected frame."

+  ;; If we start from the minibuffer window, don't fail to come back to it.

+  (if (window-minibuffer-p (selected-window))

+      (setq minibuf t))

+  (save-selected-window

+    (if (framep all-frames)

+        (select-window (frame-first-window all-frames)))

+    (let* (walk-windows-already-seen

+           (walk-windows-current (selected-window)))

+      (while (progn

+               (setq walk-windows-current

+                     (next-window walk-windows-current minibuf all-frames))

+               (not (memq walk-windows-current walk-windows-already-seen)))

+        (setq walk-windows-already-seen

+              (cons walk-windows-current walk-windows-already-seen))

+        (funcall proc walk-windows-current)))))

+

+(defun get-window-with-predicate (predicate &optional minibuf

+                                            all-frames default)

+  "Return a window satisfying PREDICATE.

+

+This function cycles through all visible windows using `walk-windows',

+calling PREDICATE on each one.  PREDICATE is called with a window as

+argument.  The first window for which PREDICATE returns a non-nil

+value is returned.  If no window satisfies PREDICATE, DEFAULT is

+returned.

+

+Optional second arg MINIBUF t means count the minibuffer window even

+if not active.  MINIBUF nil or omitted means count the minibuffer only if

+it is active.  MINIBUF neither t nor nil means not to count the

+minibuffer even if it is active.

+

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

+counts, all windows on all frames that share that minibuffer count

+too.  Therefore, if you are using a separate minibuffer frame

+and the minibuffer is active and MINIBUF says it counts,

+`walk-windows' includes the windows in the frame from which you

+entered the minibuffer, as well as the minibuffer window.

+

+ALL-FRAMES is the optional third argument.

+ALL-FRAMES nil or omitted means cycle within the frames as specified above.

+ALL-FRAMES = `visible' means include windows on all visible frames.

+ALL-FRAMES = 0 means include windows on all visible and iconified frames.

+ALL-FRAMES = t means include windows on all frames including invisible frames.

+If ALL-FRAMES is a frame, it means include windows on that frame.

+Anything else means restrict to the selected frame."

+  (catch 'found

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

+                      (when (funcall predicate window)

+                        (throw 'found window)))

+                  minibuf all-frames)

+    default))

+

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

+

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

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

+  "Return list of all windows displaying BUFFER, or nil if none.

+BUFFER can be a buffer or a buffer name.

+See `walk-windows' for the meaning of MINIBUF and ALL-FRAMES."

+  (let ((buffer (if (bufferp buffer) buffer (get-buffer buffer))) 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 (a minibuffer window) is now active."

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

+

+(defun count-windows (&optional minibuf)

+   "Return the number of visible windows.

+This counts the windows in the selected frame and (if the minibuffer is

+to be counted) its minibuffer frame (if that's not the same frame).

+The optional arg MINIBUF non-nil means count the minibuffer

+even if it is inactive."

+   (let ((count 0))

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

+                   minibuf)

+     count))

+

+(defun window-safely-shrinkable-p (&optional window)

+  "Non-nil if the WINDOW can be shrunk without shrinking other windows.

+If WINDOW is nil or omitted, it defaults to the currently selected window."

+  (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))))))))

+

+

+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

+;;; `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)))))

+

+;;; A different solution to balance-windows

+

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

+  "Non-nil if WINDOW cannot be resized in DIRECTION.

+DIRECTION can be nil (i.e. any), `height' or `width'."

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

+    (let ((fixed (and (boundp 'window-size-fixed) window-size-fixed)))

+      (when fixed

+        (not (and direction

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

+                          '((height . width) (width . height)))))))))

+

+(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

+  "Non-nil means `display-buffer' should make a separate frame."

+  :type 'boolean

+  :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 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 modeline.

+

+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 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 FRAME if it can be used to display another buffer."

+  (when (framep 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 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)

+  "Deiconify the frame containing the window WINDOW.

+Do not deiconify 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)))))

+      (when (eq visible 'icon)

+        (make-frame-visible frame))

+      (raise-frame frame))

+    window))

+

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

+  "Display buffer BUFFER in window 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,

+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))

+         ;; `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 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 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'.

+

+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)))))

+    (set-buffer buffer)

+    (select-window (display-buffer buffer other-window) norecord)

+    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 arg)

+  "Split current window into two windows, one above the other.

+The uppermost window gets ARG lines and the other gets the rest.

+Negative ARG means select the size of the lowermost window instead.

+With no argument, split equally or close to it.

+Both windows display the same buffer now current.

+

+If the variable `split-window-keep-point' is non-nil, both new windows

+will get the same value of point as the current 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-w (selected-window))

+        (old-point (point))

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

+        (window-full-p nil)

+        new-w bottom moved)

+    (and size (< size 0) (setq size (+ (window-height) size)))

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

+    (or split-window-keep-point

+        (progn

+          (save-excursion

+            (set-buffer (window-buffer))

+            (goto-char (window-start))

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

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

+            (if (> (point) (window-point new-w))

+                (set-window-point new-w (point)))

+            (and (= moved (window-height))

+                 (progn

+                   (setq window-full-p t)

+                   (vertical-motion -1)))

+            (setq bottom (point)))

+          (and window-full-p

+               (<= bottom (point))

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

+          (and window-full-p

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

+               (progn

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

+                 (select-window new-w)))))

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

+

+;; This is to avoid compiler warnings.

+(defvar view-return-to-alist)

+

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

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

+    (if view-mode

+        (let ((old-info (assq old-w view-return-to-alist)))

+          (if old-info

+              (push (cons new-w (cons (car (cdr old-info)) t))

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

+    new-w))

+

+(defun split-window-horizontally (&optional arg)

+  "Split current window into two windows side by side.

+This window becomes the leftmost of the two, and gets ARG columns.

+Negative ARG means select the size of the rightmost window instead.

+The argument includes the width of the window's scroll bar; if there

+are no scroll bars, it includes the width of the divider column

+to the window's right, if any.  No ARG means split equally.

+

+The original, leftmost window remains selected.

+The return value is the new, rightmost window."

+  (interactive "P")

+  (let ((old-w (selected-window))

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

+    (and size (< size 0)

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

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

+

+

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

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

+This doesn't include the mode-line (or header-line if any) or any

+partial-height lines in the text display area.

+

+If WINDOW is nil, the selected window is used.

+

+Note that the current implementation of this function cannot always set

+the height exactly, but attempts to be conservative, by allocating more

+lines than are actually needed in the case where some error may be present."

+  (let ((delta (- height (window-text-height window))))

+    (unless (zerop delta)

+      ;; 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)

+              (enlarge-window delta))

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

+

+

+(defun enlarge-window-horizontally (arg)

+  "Make current window ARG columns wider."

+  (interactive "p")

+  (enlarge-window arg t))

+

+(defun shrink-window-horizontally (arg)

+  "Make current window ARG columns narrower."

+  (interactive "p")

+  (shrink-window arg 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)

+  "Make WINDOW the right height to display its contents exactly.

+If WINDOW is omitted or nil, it defaults to the selected window.

+If the optional argument MAX-HEIGHT is supplied, it is the maximum height

+  the window is allowed to be, defaulting to the frame height.

+If the optional argument MIN-HEIGHT is supplied, it is the minimum

+  height the window is allowed to be, defaulting to `window-min-height'.

+

+The heights in MAX-HEIGHT and MIN-HEIGHT include the mode-line and/or

+header-line."

+  (interactive)

+

+  (when (null window)

+    (setq window (selected-window)))

+  (when (null max-height)

+    (setq max-height (frame-height (window-frame window))))

+

+  (let* ((buf

+          ;; Buffer that is displayed in WINDOW

+          (window-buffer window))

+         (window-height

+          ;; The current height of WINDOW

+          (window-height window))

+         (desired-height

+          ;; The height necessary to show the buffer displayed by WINDOW

+          ;; (`count-screen-lines' always works on the current buffer).

+          (with-current-buffer buf

+            (+ (count-screen-lines)

+               ;; If the buffer is empty, (count-screen-lines) is

+               ;; zero.  But, even in that case, we need one text line

+               ;; for cursor.

+               (if (= (point-min) (point-max))

+                   1 0)

+               ;; For non-minibuffers, count the mode-line, if any

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

+                        mode-line-format)

+                   1 0)

+               ;; Count the header-line, if any

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

+         (delta

+          ;; Calculate how much the window height has to change to show

+          ;; desired-height lines, constrained by MIN-HEIGHT and MAX-HEIGHT.

+          (- (max (min desired-height max-height)

+                  (or min-height window-min-height))

+             window-height)))

+

+    ;; Don't try to redisplay with the cursor at the end

+    ;; on its own line--that would force a scroll and spoil things.

+    (when (with-current-buffer buf

+            (and (eobp) (bolp) (not (bobp))))

+      (set-window-point window (1- (window-point window))))

+

+    (save-selected-window

+      (select-window window)

+

+      ;; Adjust WINDOW to the nominally correct size (which may actually

+      ;; be slightly off because of variable height text, etc).

+      (unless (zerop delta)

+        (enlarge-window delta))

+

+      ;; Check if the last line is surely fully visible.  If not,

+      ;; enlarge the window.

+      (let ((end (with-current-buffer buf

+                   (save-excursion

+                     (goto-char (point-max))

+                     (when (and (bolp) (not (bobp)))

+                       ;; Don't include final newline

+                       (backward-char 1))

+                     (when truncate-lines

+                       ;; If line-wrapping is turned off, test the

+                       ;; beginning of the last line for visibility

+                       ;; instead of the end, as the end of the line

+                       ;; could be invisible by virtue of extending past

+                       ;; the edge of the window.

+                       (forward-line 0))

+                     (point)))))

+        (set-window-vscroll window 0)

+        (while (and (< desired-height max-height)

+                    (= desired-height (window-height window))

+                    (not (pos-visible-in-window-p end window)))

+          (enlarge-window 1)

+          (setq desired-height (1+ desired-height)))))))

+

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

+  "Shrink the WINDOW to be as small as possible to display its contents.

+If WINDOW is omitted or nil, it defaults to the selected window.

+Do not shrink to less than `window-min-height' lines.

+Do nothing if the buffer contains more lines than the present window height,

+or if some of the window's contents are scrolled out of view,

+or if shrinking this window would also shrink another window,

+or if the window is the only window of its frame."

+  (interactive)

+  (when (null window)

+    (setq window (selected-window)))

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

+         (mini (frame-parameter frame 'minibuffer))

+         (edges (window-edges window)))

+    (if (and (not (eq window (frame-root-window frame)))

+             (window-safely-shrinkable-p)

+             (pos-visible-in-window-p (point-min) window)

+             (not (eq mini 'only))

+             (or (not mini)

+                 (let ((mini-window (minibuffer-window frame)))

+                   (or (null mini-window)

+                       (not (eq frame (window-frame mini-window)))

+                       (< (nth 3 edges)

+                          (nth 1 (window-edges mini-window)))

+                       (> (nth 1 edges)

+                          (frame-parameter frame 'menu-bar-lines))))))

+        (fit-window-to-buffer window (window-height window)))))

+

+(defun kill-buffer-and-window ()

+  "Kill the current buffer and delete the selected window."

+  (interactive)

+  (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 the current buffer.  Bury it, and maybe delete the selected frame.

+\(The frame is deleted if it contains a dedicated window for the buffer.)

+With a prefix argument, kill the buffer instead.

+

+Noninteractively, if KILL is non-nil, then kill the current buffer,

+otherwise bury it.

+

+If WINDOW is non-nil, it specifies a window; we delete that window,

+and the buffer that is killed or buried is the one in that window."

+  (interactive "P")

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

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

+        (window-solitary

+         (save-selected-window

+           (if window

+               (select-window window))

+           (one-window-p t)))

+        window-handled)

+

+    (save-selected-window

+      (if window

+          (select-window window))

+      (or (window-minibuffer-p)

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

+          (switch-to-buffer (other-buffer))))

+

+    ;; Get rid of the frame, if it has just one dedicated window

+    ;; and other visible frames exist.

+    (and (or (window-minibuffer-p) (window-dedicated-p window))

+         (delq frame (visible-frame-list))

+         window-solitary

+         (if (and (eq default-minibuffer-frame frame)

+                  (= 1 (length (minibuffer-frame-list))))

+             (setq window nil)

+           (delete-frame frame)

+           (setq window-handled t)))

+

+    ;; Deal with the buffer.

+    (if kill

+        (kill-buffer buffer)

+      (bury-buffer buffer))

+

+    ;; Maybe get rid of the window.

+    (and window (not window-handled) (not window-solitary)

+         (delete-window window))))

+

+(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)

+  "Non-nil if lines in WINDOW are specifically truncated due to its width.

+This returns 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.

+If WINDOW is nil, use the selected 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