lisp/window.el

   1 ;;; window.el --- GNU Emacs window commands aside from those written in C
   2
   3 ;; Copyright (C) 1985, 1989, 1992, 1993, 1994, 2000, 2001, 2002,
   4 ;;   2003, 2004, 2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: internal
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Window tree functions.
  29
  30 ;;; Code:
  31
  32 (defvar window-size-fixed nil
  33  "*Non-nil in a buffer means windows displaying the buffer are fixed-size.
  34 If the value is `height', then only the window's height is fixed.
  35 If the value is `width', then only the window's width is fixed.
  36 Any other non-nil value fixes both the width and the height.
  37 Emacs won't change the size of any window displaying that buffer,
  38 unless you explicitly change the size, or Emacs has no other choice.")
  39 (make-variable-buffer-local 'window-size-fixed)
  40
  41 (defmacro save-selected-window (&rest body)
  42   "Execute BODY, then select the window that was selected before BODY.
  43 The value returned is the value of the last form in BODY.
  44
  45 This macro saves and restores the current buffer, since otherwise
  46 its normal operation could potentially make a different
  47 buffer current.  It does not alter the buffer list ordering.
  48
  49 This macro saves and restores the selected window, as well as
  50 the selected window in each frame.  If the previously selected
  51 window of some frame is no longer live at the end of BODY, that
  52 frame's selected window is left alone.  If the selected window is
  53 no longer live, then whatever window is selected at the end of
  54 BODY remains selected."
  55   `(let ((save-selected-window-window (selected-window))
  56          ;; It is necessary to save all of these, because calling
  57          ;; select-window changes frame-selected-window for whatever
  58          ;; frame that window is in.
  59          (save-selected-window-alist
  60           (mapcar (lambda (frame) (list frame (frame-selected-window frame)))
  61                   (frame-list))))
  62      (save-current-buffer
  63        (unwind-protect
  64            (progn ,@body)
  65          (dolist (elt save-selected-window-alist)
  66            (and (frame-live-p (car elt))
  67                 (window-live-p (cadr elt))
  68                 (set-frame-selected-window (car elt) (cadr elt))))
  69          (if (window-live-p save-selected-window-window)
  70              (select-window save-selected-window-window))))))
  71
  72 (defun window-body-height (&optional window)
  73   "Return number of lines in window WINDOW for actual buffer text.
  74 This does not include the mode line (if any) or the header line (if any)."
  75   (or window (setq window (selected-window)))
  76   (if (window-minibuffer-p window)
  77       (window-height window)
  78     (with-current-buffer (window-buffer window)
  79       (max 1 (- (window-height window)
  80                 (if mode-line-format 1 0)
  81                 (if header-line-format 1 0))))))
  82
  83 (defun one-window-p (&optional nomini all-frames)
  84   "Return non-nil if the selected window is the only window.
  85 Optional arg NOMINI non-nil means don't count the minibuffer
  86 even if it is active.  Otherwise, the minibuffer is counted
  87 when it is active.
  88
  89 The optional arg ALL-FRAMES t means count windows on all frames.
  90 If it is `visible', count windows on all visible frames.
  91 ALL-FRAMES nil or omitted means count only the selected frame,
  92 plus the minibuffer it uses (which may be on another frame).
  93 ALL-FRAMES 0 means count all windows in all visible or iconified frames.
  94 If ALL-FRAMES is anything else, count only the selected frame."
  95   (let ((base-window (selected-window)))
  96     (if (and nomini (eq base-window (minibuffer-window)))
  97         (setq base-window (next-window base-window)))
  98     (eq base-window
  99         (next-window base-window (if nomini 'arg) all-frames))))
 100
 101 (defun window-current-scroll-bars (&optional window)
 102   "Return the current scroll-bar settings in window WINDOW.
 103 Value is a cons (VERTICAL . HORIZONTAL) where VERTICAL specifies the
 104 current location of the vertical scroll-bars (left, right, or nil),
 105 and HORIZONTAL specifies the current location of the horizontal scroll
 106 bars (top, bottom, or nil)."
 107   (let ((vert (nth 2 (window-scroll-bars window)))
 108         (hor nil))
 109     (when (or (eq vert t) (eq hor t))
 110       (let ((fcsb (frame-current-scroll-bars
 111                    (window-frame (or window (selected-window))))))
 112         (if (eq vert t)
 113             (setq vert (car fcsb)))
 114         (if (eq hor t)
 115             (setq hor (cdr fcsb)))))
 116     (cons vert hor)))
 117
 118 (defun walk-windows (proc &optional minibuf all-frames)
 119   "Cycle through all visible windows, calling PROC for each one.
 120 PROC is called with a window as argument.
 121
 122 Optional second arg MINIBUF t means count the minibuffer window even
 123 if not active.  MINIBUF nil or omitted means count the minibuffer iff
 124 it is active.  MINIBUF neither t nor nil means not to count the
 125 minibuffer even if it is active.
 126
 127 Several frames may share a single minibuffer; if the minibuffer
 128 counts, all windows on all frames that share that minibuffer count
 129 too.  Therefore, if you are using a separate minibuffer frame
 130 and the minibuffer is active and MINIBUF says it counts,
 131 `walk-windows' includes the windows in the frame from which you
 132 entered the minibuffer, as well as the minibuffer window.
 133
 134 ALL-FRAMES is the optional third argument.
 135 ALL-FRAMES nil or omitted means cycle within the frames as specified above.
 136 ALL-FRAMES = `visible' means include windows on all visible frames.
 137 ALL-FRAMES = 0 means include windows on all visible and iconified frames.
 138 ALL-FRAMES = t means include windows on all frames including invisible frames.
 139 If ALL-FRAMES is a frame, it means include windows on that frame.
 140 Anything else means restrict to the selected frame."
 141   ;; If we start from the minibuffer window, don't fail to come back to it.
 142   (if (window-minibuffer-p (selected-window))
 143       (setq minibuf t))
 144   (save-selected-window
 145     (if (framep all-frames)
 146         (select-window (frame-first-window all-frames)))
 147     (let* (walk-windows-already-seen
 148            (walk-windows-current (selected-window)))
 149       (while (progn
 150                (setq walk-windows-current
 151                      (next-window walk-windows-current minibuf all-frames))
 152                (not (memq walk-windows-current walk-windows-already-seen)))
 153         (setq walk-windows-already-seen
 154               (cons walk-windows-current walk-windows-already-seen))
 155         (funcall proc walk-windows-current)))))
 156
 157 (defun get-window-with-predicate (predicate &optional minibuf
 158                                             all-frames default)
 159   "Return a window satisfying PREDICATE.
 160
 161 This function cycles through all visible windows using `walk-windows',
 162 calling PREDICATE on each one.  PREDICATE is called with a window as
 163 argument.  The first window for which PREDICATE returns a non-nil
 164 value is returned.  If no window satisfies PREDICATE, DEFAULT is
 165 returned.
 166
 167 Optional second arg MINIBUF t means count the minibuffer window even
 168 if not active.  MINIBUF nil or omitted means count the minibuffer iff
 169 it is active.  MINIBUF neither t nor nil means not to count the
 170 minibuffer even if it is active.
 171
 172 Several frames may share a single minibuffer; if the minibuffer
 173 counts, all windows on all frames that share that minibuffer count
 174 too.  Therefore, if you are using a separate minibuffer frame
 175 and the minibuffer is active and MINIBUF says it counts,
 176 `walk-windows' includes the windows in the frame from which you
 177 entered the minibuffer, as well as the minibuffer window.
 178
 179 ALL-FRAMES is the optional third argument.
 180 ALL-FRAMES nil or omitted means cycle within the frames as specified above.
 181 ALL-FRAMES = `visible' means include windows on all visible frames.
 182 ALL-FRAMES = 0 means include windows on all visible and iconified frames.
 183 ALL-FRAMES = t means include windows on all frames including invisible frames.
 184 If ALL-FRAMES is a frame, it means include windows on that frame.
 185 Anything else means restrict to the selected frame."
 186   (catch 'found
 187     (walk-windows #'(lambda (window)
 188                       (when (funcall predicate window)
 189                         (throw 'found window)))
 190                   minibuf all-frames)
 191     default))
 192
 193 (defalias 'some-window 'get-window-with-predicate)
 194
 195 ;; This should probably be written in C (i.e., without using `walk-windows').
 196 (defun get-buffer-window-list (buffer &optional minibuf frame)
 197   "Return list of all windows displaying BUFFER, or nil if none.
 198 BUFFER can be a buffer or a buffer name.
 199 See `walk-windows' for the meaning of MINIBUF and FRAME."
 200   (let ((buffer (if (bufferp buffer) buffer (get-buffer buffer))) windows)
 201     (walk-windows (function (lambda (window)
 202                               (if (eq (window-buffer window) buffer)
 203                                   (setq windows (cons window windows)))))
 204                   minibuf frame)
 205     windows))
 206
 207 (defun minibuffer-window-active-p (window)
 208   "Return t if WINDOW (a minibuffer window) is now active."
 209   (eq window (active-minibuffer-window)))
 210 \f
 211 (defun count-windows (&optional minibuf)
 212    "Return the number of visible windows.
 213 This counts the windows in the selected frame and (if the minibuffer is
 214 to be counted) its minibuffer frame (if that's not the same frame).
 215 The optional arg MINIBUF non-nil means count the minibuffer
 216 even if it is inactive."
 217    (let ((count 0))
 218      (walk-windows (function (lambda (w)
 219                                (setq count (+ count 1))))
 220                    minibuf)
 221      count))
 222
 223 (defun window-safely-shrinkable-p (&optional window)
 224   "Non-nil if the WINDOW can be shrunk without shrinking other windows.
 225 If WINDOW is nil or omitted, it defaults to the currently selected window."
 226   (with-selected-window (or window (selected-window))
 227     (let ((edges (window-edges)))
 228       (or (= (nth 2 edges) (nth 2 (window-edges (previous-window))))
 229           (= (nth 0 edges) (nth 0 (window-edges (next-window))))))))
 230
 231 \f
 232 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 233 ;;; `balance-windows' subroutines using `window-tree'
 234
 235 ;;; Translate from internal window tree format
 236
 237 (defun bw-get-tree (&optional window-or-frame)
 238   "Get a window split tree in our format.
 239
 240 WINDOW-OR-FRAME must be nil, a frame, or a window.  If it is nil,
 241 then the whole window split tree for `selected-frame' is returned.
 242 If it is a frame, then this is used instead.  If it is a window,
 243 then the smallest tree containing that window is returned."
 244   (when window-or-frame
 245     (unless (or (framep window-or-frame)
 246                 (windowp window-or-frame))
 247       (error "Not a frame or window: %s" window-or-frame)))
 248   (let ((subtree (bw-find-tree-sub window-or-frame)))
 249     (when subtree
 250       (if (integerp subtree)
 251           nil
 252         (bw-get-tree-1 subtree)))))
 253
 254 (defun bw-get-tree-1 (split)
 255   (if (windowp split)
 256       split
 257     (let ((dir (car split))
 258           (edges (car (cdr split)))
 259           (childs (cdr (cdr split))))
 260       (list
 261        (cons 'dir (if dir 'ver 'hor))
 262        (cons 'b (nth 3 edges))
 263        (cons 'r (nth 2 edges))
 264        (cons 't (nth 1 edges))
 265        (cons 'l (nth 0 edges))
 266        (cons 'childs (mapcar #'bw-get-tree-1 childs))))))
 267
 268 (defun bw-find-tree-sub (window-or-frame &optional get-parent)
 269   (let* ((window (when (windowp window-or-frame) window-or-frame))
 270          (frame (when (windowp window) (window-frame window)))
 271          (wt (car (window-tree frame))))
 272     (when (< 1 (length (window-list frame 0)))
 273       (if window
 274           (bw-find-tree-sub-1 wt window get-parent)
 275         wt))))
 276
 277 (defun bw-find-tree-sub-1 (tree win &optional get-parent)
 278   (unless (windowp win) (error "Not a window: %s" win))
 279   (if (memq win tree)
 280       (if get-parent
 281           get-parent
 282         tree)
 283     (let ((childs (cdr (cdr tree)))
 284           child
 285           subtree)
 286       (while (and childs (not subtree))
 287         (setq child (car childs))
 288         (setq childs (cdr childs))
 289         (when (and child (listp child))
 290           (setq subtree (bw-find-tree-sub-1 child win get-parent))))
 291       (if (integerp subtree)
 292           (progn
 293             (if (= 1 subtree)
 294                 tree
 295               (1- subtree)))
 296         subtree
 297         ))))
 298
 299 ;;; Window or object edges
 300
 301 (defun bw-l (obj)
 302   "Left edge of OBJ."
 303   (if (windowp obj) (nth 0 (window-edges obj)) (cdr (assq 'l obj))))
 304 (defun bw-t (obj)
 305   "Top edge of OBJ."
 306   (if (windowp obj) (nth 1 (window-edges obj)) (cdr (assq 't obj))))
 307 (defun bw-r (obj)
 308   "Right edge of OBJ."
 309   (if (windowp obj) (nth 2 (window-edges obj)) (cdr (assq 'r obj))))
 310 (defun bw-b (obj)
 311   "Bottom edge of OBJ."
 312   (if (windowp obj) (nth 3 (window-edges obj)) (cdr (assq 'b obj))))
 313
 314 ;;; Split directions
 315
 316 (defun bw-dir (obj)
 317   "Return window split tree direction if OBJ.
 318 If OBJ is a window return 'both.  If it is a window split tree
 319 then return its direction."
 320   (if (symbolp obj)
 321       obj
 322     (if (windowp obj)
 323         'both
 324       (let ((dir (cdr (assq 'dir obj))))
 325         (unless (memq dir '(hor ver both))
 326           (error "Can't find dir in %s" obj))
 327         dir))))
 328
 329 (defun bw-eqdir (obj1 obj2)
 330   "Return t if window split tree directions are equal.
 331 OBJ1 and OBJ2 should be either windows or window split trees in
 332 our format.  The directions returned by `bw-dir' are compared and
 333 t is returned if they are `eq' or one of them is 'both."
 334   (let ((dir1 (bw-dir obj1))
 335         (dir2 (bw-dir obj2)))
 336     (or (eq dir1 dir2)
 337         (eq dir1 'both)
 338         (eq dir2 'both))))
 339
 340 ;;; Building split tree
 341
 342 (defun bw-refresh-edges (obj)
 343   "Refresh the edge information of OBJ and return OBJ."
 344   (unless (windowp obj)
 345     (let ((childs (cdr (assq 'childs obj)))
 346           (ol 1000)
 347           (ot 1000)
 348           (or -1)
 349           (ob -1))
 350       (dolist (o childs)
 351         (when (> ol (bw-l o)) (setq ol (bw-l o)))
 352         (when (> ot (bw-t o)) (setq ot (bw-t o)))
 353         (when (< or (bw-r o)) (setq or (bw-r o)))
 354         (when (< ob (bw-b o)) (setq ob (bw-b o))))
 355       (setq obj (delq 'l obj))
 356       (setq obj (delq 't obj))
 357       (setq obj (delq 'r obj))
 358       (setq obj (delq 'b obj))
 359       (add-to-list 'obj (cons 'l ol))
 360       (add-to-list 'obj (cons 't ot))
 361       (add-to-list 'obj (cons 'r or))
 362       (add-to-list 'obj (cons 'b ob))
 363       ))
 364   obj)
 365
 366 ;;; Balance windows
 367
 368 (defun balance-windows (&optional window-or-frame)
 369   "Make windows the same heights or widths in window split subtrees.
 370
 371 When called non-interactively WINDOW-OR-FRAME may be either a
 372 window or a frame.  It then balances the windows on the implied
 373 frame.  If the parameter is a window only the corresponding window
 374 subtree is balanced."
 375   (interactive)
 376   (let (
 377         (wt (bw-get-tree window-or-frame))
 378         (w)
 379         (h)
 380         (tried-sizes)
 381         (last-sizes)
 382         (windows (window-list nil 0))
 383         (counter 0))
 384     (when wt
 385       (while (not (member last-sizes tried-sizes))
 386         (when last-sizes (setq tried-sizes (cons last-sizes tried-sizes)))
 387         (setq last-sizes (mapcar (lambda (w)
 388                                    (window-edges w))
 389                                  windows))
 390         (when (eq 'hor (bw-dir wt))
 391           (setq w (- (bw-r wt) (bw-l wt))))
 392         (when (eq 'ver (bw-dir wt))
 393           (setq h (- (bw-b wt) (bw-t wt))))
 394         (bw-balance-sub wt w h)))))
 395
 396 (defun bw-adjust-window (window delta horizontal)
 397   "Wrapper around `adjust-window-trailing-edge' with error checking.
 398 Arguments WINDOW, DELTA and HORIZONTAL are passed on to that function."
 399   (condition-case err
 400       (adjust-window-trailing-edge window delta horizontal)
 401     (error
 402      ;;(message "adjust: %s" (error-message-string err))
 403      )))
 404
 405 (defun bw-balance-sub (wt w h)
 406   (setq wt (bw-refresh-edges wt))
 407   (unless w (setq w (- (bw-r wt) (bw-l wt))))
 408   (unless h (setq h (- (bw-b wt) (bw-t wt))))
 409   (if (windowp wt)
 410       (progn
 411         (when w
 412           (let ((dw (- w (- (bw-r wt) (bw-l wt)))))
 413             (when (/= 0 dw)
 414                 (bw-adjust-window wt dw t))))
 415         (when h
 416           (let ((dh (- h (- (bw-b wt) (bw-t wt)))))
 417             (when (/= 0 dh)
 418               (bw-adjust-window wt dh nil)))))
 419     (let* ((childs (cdr (assq 'childs wt)))
 420            (lastchild (car (last childs)))
 421            (cw (when w (/ w (if (bw-eqdir 'hor wt) (length childs) 1))))
 422            (ch (when h (/ h (if (bw-eqdir 'ver wt) (length childs) 1)))))
 423       (dolist (c childs)
 424           (bw-balance-sub c cw ch)))))
 425
 426 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 427 \f
 428 ;; I think this should be the default; I think people will prefer it--rms.
 429 (defcustom split-window-keep-point t
 430   "*If non-nil, \\[split-window-vertically] keeps the original point \
 431 in both children.
 432 This is often more convenient for editing.
 433 If nil, adjust point in each of the two windows to minimize redisplay.
 434 This is convenient on slow terminals, but point can move strangely.
 435
 436 This option applies only to `split-window-vertically' and
 437 functions that call it.  `split-window' always keeps the original
 438 point in both children."
 439   :type 'boolean
 440   :group 'windows)
 441
 442 (defun split-window-vertically (&optional arg)
 443   "Split current window into two windows, one above the other.
 444 The uppermost window gets ARG lines and the other gets the rest.
 445 Negative ARG means select the size of the lowermost window instead.
 446 With no argument, split equally or close to it.
 447 Both windows display the same buffer now current.
 448
 449 If the variable `split-window-keep-point' is non-nil, both new windows
 450 will get the same value of point as the current window.  This is often
 451 more convenient for editing.  The upper window is the selected window.
 452
 453 Otherwise, we choose window starts so as to minimize the amount of
 454 redisplay; this is convenient on slow terminals.  The new selected
 455 window is the one that the current value of point appears in.  The
 456 value of point can change if the text around point is hidden by the
 457 new mode line.
 458
 459 Regardless of the value of `split-window-keep-point', the upper
 460 window is the original one and the return value is the new, lower
 461 window."
 462   (interactive "P")
 463   (let ((old-w (selected-window))
 464         (old-point (point))
 465         (size (and arg (prefix-numeric-value arg)))
 466         (window-full-p nil)
 467         new-w bottom switch moved)
 468     (and size (< size 0) (setq size (+ (window-height) size)))
 469     (setq new-w (split-window nil size))
 470     (or split-window-keep-point
 471         (progn
 472           (save-excursion
 473             (set-buffer (window-buffer))
 474             (goto-char (window-start))
 475             (setq moved (vertical-motion (window-height)))
 476             (set-window-start new-w (point))
 477             (if (> (point) (window-point new-w))
 478                 (set-window-point new-w (point)))
 479             (and (= moved (window-height))
 480                  (progn
 481                    (setq window-full-p t)
 482                    (vertical-motion -1)))
 483             (setq bottom (point)))
 484           (and window-full-p
 485                (<= bottom (point))
 486                (set-window-point old-w (1- bottom)))
 487           (and window-full-p
 488                (<= (window-start new-w) old-point)
 489                (progn
 490                  (set-window-point new-w old-point)
 491                  (select-window new-w)))))
 492     (split-window-save-restore-data new-w old-w)))
 493
 494 ;; This is to avoid compiler warnings.
 495 (defvar view-return-to-alist)
 496
 497 (defun split-window-save-restore-data (new-w old-w)
 498   (with-current-buffer (window-buffer)
 499     (if view-mode
 500         (let ((old-info (assq old-w view-return-to-alist)))
 501           (if old-info
 502               (push (cons new-w (cons (car (cdr old-info)) t))
 503                     view-return-to-alist))))
 504     new-w))
 505
 506 (defun split-window-horizontally (&optional arg)
 507   "Split current window into two windows side by side.
 508 This window becomes the leftmost of the two, and gets ARG columns.
 509 Negative ARG means select the size of the rightmost window instead.
 510 The argument includes the width of the window's scroll bar; if there
 511 are no scroll bars, it includes the width of the divider column
 512 to the window's right, if any.  No ARG means split equally.
 513
 514 The original, leftmost window remains selected.
 515 The return value is the new, rightmost window."
 516   (interactive "P")
 517   (let ((old-w (selected-window))
 518         (size (and arg (prefix-numeric-value arg))))
 519     (and size (< size 0)
 520          (setq size (+ (window-width) size)))
 521     (split-window-save-restore-data (split-window nil size t) old-w)))
 522
 523 \f
 524 (defun set-window-text-height (window height)
 525   "Sets the height in lines of the text display area of WINDOW to HEIGHT.
 526 This doesn't include the mode-line (or header-line if any) or any
 527 partial-height lines in the text display area.
 528
 529 If WINDOW is nil, the selected window is used.
 530
 531 Note that the current implementation of this function cannot always set
 532 the height exactly, but attempts to be conservative, by allocating more
 533 lines than are actually needed in the case where some error may be present."
 534   (let ((delta (- height (window-text-height window))))
 535     (unless (zerop delta)
 536       ;; Setting window-min-height to a value like 1 can lead to very
 537       ;; bizarre displays because it also allows Emacs to make *other*
 538       ;; windows 1-line tall, which means that there's no more space for
 539       ;; the modeline.
 540       (let ((window-min-height (min 2 height))) ;One text line plus a modeline.
 541         (if (and window (not (eq window (selected-window))))
 542             (save-selected-window
 543               (select-window window)
 544               (enlarge-window delta))
 545           (enlarge-window delta))))))
 546
 547 \f
 548 (defun enlarge-window-horizontally (arg)
 549   "Make current window ARG columns wider."
 550   (interactive "p")
 551   (enlarge-window arg t))
 552
 553 (defun shrink-window-horizontally (arg)
 554   "Make current window ARG columns narrower."
 555   (interactive "p")
 556   (shrink-window arg t))
 557
 558 (defun window-buffer-height (window)
 559   "Return the height (in screen lines) of the buffer that WINDOW is displaying."
 560   (with-current-buffer (window-buffer window)
 561     (max 1
 562          (count-screen-lines (point-min) (point-max)
 563                              ;; If buffer ends with a newline, ignore it when
 564                              ;; counting height unless point is after it.
 565                              (eobp)
 566                              window))))
 567
 568 (defun count-screen-lines (&optional beg end count-final-newline window)
 569   "Return the number of screen lines in the region.
 570 The number of screen lines may be different from the number of actual lines,
 571 due to line breaking, display table, etc.
 572
 573 Optional arguments BEG and END default to `point-min' and `point-max'
 574 respectively.
 575
 576 If region ends with a newline, ignore it unless optional third argument
 577 COUNT-FINAL-NEWLINE is non-nil.
 578
 579 The optional fourth argument WINDOW specifies the window used for obtaining
 580 parameters such as width, horizontal scrolling, and so on.  The default is
 581 to use the selected window's parameters.
 582
 583 Like `vertical-motion', `count-screen-lines' always uses the current buffer,
 584 regardless of which buffer is displayed in WINDOW.  This makes possible to use
 585 `count-screen-lines' in any buffer, whether or not it is currently displayed
 586 in some window."
 587   (unless beg
 588     (setq beg (point-min)))
 589   (unless end
 590     (setq end (point-max)))
 591   (if (= beg end)
 592       0
 593     (save-excursion
 594       (save-restriction
 595         (widen)
 596         (narrow-to-region (min beg end)
 597                           (if (and (not count-final-newline)
 598                                    (= ?\n (char-before (max beg end))))
 599                               (1- (max beg end))
 600                             (max beg end)))
 601         (goto-char (point-min))
 602         (1+ (vertical-motion (buffer-size) window))))))
 603
 604 (defun fit-window-to-buffer (&optional window max-height min-height)
 605   "Make WINDOW the right height to display its contents exactly.
 606 If WINDOW is omitted or nil, it defaults to the selected window.
 607 If the optional argument MAX-HEIGHT is supplied, it is the maximum height
 608   the window is allowed to be, defaulting to the frame height.
 609 If the optional argument MIN-HEIGHT is supplied, it is the minimum
 610   height the window is allowed to be, defaulting to `window-min-height'.
 611
 612 The heights in MAX-HEIGHT and MIN-HEIGHT include the mode-line and/or
 613 header-line."
 614   (interactive)
 615
 616   (when (null window)
 617     (setq window (selected-window)))
 618   (when (null max-height)
 619     (setq max-height (frame-height (window-frame window))))
 620
 621   (let* ((buf
 622           ;; Buffer that is displayed in WINDOW
 623           (window-buffer window))
 624          (window-height
 625           ;; The current height of WINDOW
 626           (window-height window))
 627          (desired-height
 628           ;; The height necessary to show the buffer displayed by WINDOW
 629           ;; (`count-screen-lines' always works on the current buffer).
 630           (with-current-buffer buf
 631             (+ (count-screen-lines)
 632                ;; If the buffer is empty, (count-screen-lines) is
 633                ;; zero.  But, even in that case, we need one text line
 634                ;; for cursor.
 635                (if (= (point-min) (point-max))
 636                    1 0)
 637                ;; For non-minibuffers, count the mode-line, if any
 638                (if (and (not (window-minibuffer-p window))
 639                         mode-line-format)
 640                    1 0)
 641                ;; Count the header-line, if any
 642                (if header-line-format 1 0))))
 643          (delta
 644           ;; Calculate how much the window height has to change to show
 645           ;; desired-height lines, constrained by MIN-HEIGHT and MAX-HEIGHT.
 646           (- (max (min desired-height max-height)
 647                   (or min-height window-min-height))
 648              window-height))
 649          ;; We do our own height checking, so avoid any restrictions due to
 650          ;; window-min-height.
 651          (window-min-height 1))
 652
 653     ;; Don't try to redisplay with the cursor at the end
 654     ;; on its own line--that would force a scroll and spoil things.
 655     (when (with-current-buffer buf
 656             (and (eobp) (bolp) (not (bobp))))
 657       (set-window-point window (1- (window-point window))))
 658
 659     (save-selected-window
 660       (select-window window)
 661
 662       ;; Adjust WINDOW to the nominally correct size (which may actually
 663       ;; be slightly off because of variable height text, etc).
 664       (unless (zerop delta)
 665         (enlarge-window delta))
 666
 667       ;; Check if the last line is surely fully visible.  If not,
 668       ;; enlarge the window.
 669       (let ((end (with-current-buffer buf
 670                    (save-excursion
 671                      (goto-char (point-max))
 672                      (when (and (bolp) (not (bobp)))
 673                        ;; Don't include final newline
 674                        (backward-char 1))
 675                      (when truncate-lines
 676                        ;; If line-wrapping is turned off, test the
 677                        ;; beginning of the last line for visibility
 678                        ;; instead of the end, as the end of the line
 679                        ;; could be invisible by virtue of extending past
 680                        ;; the edge of the window.
 681                        (forward-line 0))
 682                      (point)))))
 683         (set-window-vscroll window 0)
 684         (while (and (< desired-height max-height)
 685                     (= desired-height (window-height window))
 686                     (not (pos-visible-in-window-p end window)))
 687           (enlarge-window 1)
 688           (setq desired-height (1+ desired-height)))))))
 689
 690 (defun shrink-window-if-larger-than-buffer (&optional window)
 691   "Shrink the WINDOW to be as small as possible to display its contents.
 692 If WINDOW is omitted or nil, it defaults to the selected window.
 693 Do not shrink to less than `window-min-height' lines.
 694 Do nothing if the buffer contains more lines than the present window height,
 695 or if some of the window's contents are scrolled out of view,
 696 or if shrinking this window would also shrink another window,
 697 or if the window is the only window of its frame."
 698   (interactive)
 699   (when (null window)
 700     (setq window (selected-window)))
 701   (let* ((frame (window-frame window))
 702          (mini (frame-parameter frame 'minibuffer))
 703          (edges (window-edges window)))
 704     (if (and (not (eq window (frame-root-window frame)))
 705              (window-safely-shrinkable-p)
 706              (pos-visible-in-window-p (point-min) window)
 707              (not (eq mini 'only))
 708              (or (not mini)
 709                  (let ((mini-window (minibuffer-window frame)))
 710                    (or (null mini-window)
 711                        (not (eq frame (window-frame mini-window)))
 712                        (< (nth 3 edges)
 713                           (nth 1 (window-edges mini-window)))
 714                        (> (nth 1 edges)
 715                           (frame-parameter frame 'menu-bar-lines))))))
 716         (fit-window-to-buffer window (window-height window)))))
 717
 718 (defun kill-buffer-and-window ()
 719   "Kill the current buffer and delete the selected window."
 720   (interactive)
 721   (let ((window-to-delete (selected-window))
 722         (delete-window-hook (lambda ()
 723                               (condition-case nil
 724                                   (delete-window)
 725                                 (error nil)))))
 726     (add-hook 'kill-buffer-hook delete-window-hook t t)
 727     (if (kill-buffer (current-buffer))
 728         ;; If `delete-window' failed before, we rerun it to regenerate
 729         ;; the error so it can be seen in the minibuffer.
 730         (when (eq (selected-window) window-to-delete)
 731           (delete-window))
 732       (remove-hook 'kill-buffer-hook delete-window-hook t))))
 733
 734 (defun quit-window (&optional kill window)
 735   "Quit the current buffer.  Bury it, and maybe delete the selected frame.
 736 \(The frame is deleted if it contains a dedicated window for the buffer.)
 737 With a prefix argument, kill the buffer instead.
 738
 739 Noninteractively, if KILL is non-nil, then kill the current buffer,
 740 otherwise bury it.
 741
 742 If WINDOW is non-nil, it specifies a window; we delete that window,
 743 and the buffer that is killed or buried is the one in that window."
 744   (interactive "P")
 745   (let ((buffer (window-buffer window))
 746         (frame (window-frame (or window (selected-window))))
 747         (window-solitary
 748          (save-selected-window
 749            (if window
 750                (select-window window))
 751            (one-window-p t)))
 752         window-handled)
 753
 754     (save-selected-window
 755       (if window
 756           (select-window window))
 757       (or (window-minibuffer-p)
 758           (window-dedicated-p (selected-window))
 759           (switch-to-buffer (other-buffer))))
 760
 761     ;; Get rid of the frame, if it has just one dedicated window
 762     ;; and other visible frames exist.
 763     (and (or (window-minibuffer-p) (window-dedicated-p window))
 764          (delq frame (visible-frame-list))
 765          window-solitary
 766          (if (and (eq default-minibuffer-frame frame)
 767                   (= 1 (length (minibuffer-frame-list))))
 768              (setq window nil)
 769            (delete-frame frame)
 770            (setq window-handled t)))
 771
 772     ;; Deal with the buffer.
 773     (if kill
 774         (kill-buffer buffer)
 775       (bury-buffer buffer))
 776
 777     ;; Maybe get rid of the window.
 778     (and window (not window-handled) (not window-solitary)
 779          (delete-window window))))
 780 \f
 781 (defvar mouse-autoselect-window-timer nil
 782   "Timer used by delayed window autoselection.")
 783
 784 (defvar mouse-autoselect-window-position nil
 785   "Last mouse position recorded by delayed window autoselection.")
 786
 787 (defvar mouse-autoselect-window-window nil
 788   "Last window recorded by delayed window autoselection.")
 789
 790 (defvar mouse-autoselect-window-now nil
 791   "When non-nil don't delay autoselection in `handle-select-window'.")
 792
 793 (defun mouse-autoselect-window-cancel (&optional force)
 794   "Cancel delayed window autoselection.
 795 Optional argument FORCE means cancel unconditionally."
 796   (unless (and (not force)
 797                ;; Don't cancel while the user drags a scroll bar.
 798                (eq this-command 'scroll-bar-toolkit-scroll)
 799                (memq (nth 4 (event-end last-input-event))
 800                      '(handle end-scroll)))
 801     (setq mouse-autoselect-window-now nil)
 802     (when (timerp mouse-autoselect-window-timer)
 803       (cancel-timer mouse-autoselect-window-timer))
 804     (remove-hook 'pre-command-hook 'mouse-autoselect-window-cancel)))
 805
 806 (defun mouse-autoselect-window-start (window)
 807   "Start delayed window autoselection.
 808 Called when Emacs detects that the mouse has moved to the non-selected
 809 window WINDOW and the variable `mouse-autoselect-window' has a numeric,
 810 non-zero value.  The return value is non-nil iff delayed autoselection
 811 started successfully.  Delayed window autoselection is canceled when the
 812 mouse position has stabilized or a command is executed."
 813   ;; Cancel any active window autoselection.
 814   (mouse-autoselect-window-cancel t)
 815   ;; Record current mouse position in `mouse-autoselect-window-position' and
 816   ;; WINDOW in `mouse-autoselect-window-window'.
 817   (setq mouse-autoselect-window-position (mouse-position))
 818   (setq mouse-autoselect-window-window window)
 819   ;; Install timer which runs `mouse-autoselect-window-select' every
 820   ;; `mouse-autoselect-window' seconds.
 821   (setq mouse-autoselect-window-timer
 822         (run-at-time
 823          (abs mouse-autoselect-window) (abs mouse-autoselect-window)
 824          'mouse-autoselect-window-select))
 825   ;; Executing a command cancels window autoselection.
 826   (add-hook 'pre-command-hook 'mouse-autoselect-window-cancel))
 827
 828 (defun mouse-autoselect-window-select ()
 829   "Select window with delayed window autoselection.
 830 If the mouse position has stabilized in a non-selected window, select
 831 that window.  The minibuffer window is selected iff the minibuffer is
 832 active.  This function is run by `mouse-autoselect-window-timer'."
 833   (condition-case nil
 834       (let* ((mouse-position (mouse-position))
 835              (window (window-at (cadr mouse-position) (cddr mouse-position)
 836                                 (car mouse-position))))
 837         (cond
 838          ((and window (not (eq window (selected-window)))
 839                (or (not (numberp mouse-autoselect-window))
 840                    (and (> mouse-autoselect-window 0)
 841                         ;; If `mouse-autoselect-window' is positive, select
 842                         ;; window if the window is the same as before.
 843                         (eq window mouse-autoselect-window-window))
 844                    ;; Otherwise select window iff the mouse is at the same
 845                    ;; position as before.  Observe that the first test after
 846                    ;; `mouse-autoselect-window-start' usually fails since the
 847                    ;; value of `mouse-autoselect-window-position' recorded there
 848                    ;; is the position where the mouse has entered the new window
 849                    ;; and not necessarily where the mouse has stopped moving.
 850                    (equal mouse-position mouse-autoselect-window-position))
 851                ;; The minibuffer is a candidate window iff it's active.
 852                (or (not (window-minibuffer-p window))
 853                    (eq window (active-minibuffer-window))))
 854           ;; Mouse position has stabilized in non-selected window: Cancel window
 855           ;; autoselection and try to select that window.
 856           (mouse-autoselect-window-cancel t)
 857           ;; Select window where mouse appears unless the selected window is the
 858           ;; minibuffer.  Use `unread-command-events' in order to execute pre-
 859           ;; and post-command hooks and trigger idle timers.  To avoid delaying
 860           ;; autoselection again, temporarily set `mouse-autoselect-window-now'
 861           ;; to t.
 862           (unless (window-minibuffer-p (selected-window))
 863             (setq mouse-autoselect-window-now t)
 864             (setq unread-command-events
 865                   (cons (list 'select-window (list window))
 866                         unread-command-events))))
 867          ((or (and window (eq window (selected-window)))
 868               (not (numberp mouse-autoselect-window))
 869               (equal mouse-position mouse-autoselect-window-position))
 870           ;; Mouse position has either stabilized in the selected window or at
 871           ;; `mouse-autoselect-window-position': Cancel window autoselection.
 872           (mouse-autoselect-window-cancel t))
 873          (t
 874           ;; Mouse position has not stabilized yet, record new mouse position in
 875           ;; `mouse-autoselect-window-position' and any window at that position
 876           ;; in `mouse-autoselect-window-window'.
 877           (setq mouse-autoselect-window-position mouse-position)
 878           (setq mouse-autoselect-window-window window))))
 879     (error nil)))
 880
 881 (defun handle-select-window (event)
 882   "Handle select-window events."
 883   (interactive "e")
 884   (let ((window (posn-window (event-start event))))
 885     (when (and (window-live-p window)
 886                ;; Don't switch if we're currently in the minibuffer.
 887                ;; This tries to work around problems where the minibuffer gets
 888                ;; unselected unexpectedly, and where you then have to move
 889                ;; your mouse all the way down to the minibuffer to select it.
 890                (not (window-minibuffer-p (selected-window)))
 891                ;; Don't switch to a minibuffer window unless it's active.
 892                (or (not (window-minibuffer-p window))
 893                    (minibuffer-window-active-p window)))
 894       (unless (and (numberp mouse-autoselect-window)
 895                    (not (zerop mouse-autoselect-window))
 896                    (not mouse-autoselect-window-now)
 897                    ;; When `mouse-autoselect-window' has a numeric, non-zero
 898                    ;; value, delay window autoselection by that value.
 899                    ;; `mouse-autoselect-window-start' returns non-nil iff it
 900                    ;; successfully installed a timer for this purpose.
 901                    (mouse-autoselect-window-start window))
 902         ;; Re-enable delayed window autoselection.
 903         (setq mouse-autoselect-window-now nil)
 904         (when mouse-autoselect-window
 905           ;; Run `mouse-leave-buffer-hook' when autoselecting window.
 906           (run-hooks 'mouse-leave-buffer-hook))
 907         (select-window window)))))
 908
 909 (define-key ctl-x-map "2" 'split-window-vertically)
 910 (define-key ctl-x-map "3" 'split-window-horizontally)
 911 (define-key ctl-x-map "}" 'enlarge-window-horizontally)
 912 (define-key ctl-x-map "{" 'shrink-window-horizontally)
 913 (define-key ctl-x-map "-" 'shrink-window-if-larger-than-buffer)
 914 (define-key ctl-x-map "+" 'balance-windows)
 915 (define-key ctl-x-4-map "0" 'kill-buffer-and-window)
 916
 917 ;; arch-tag: b508dfcc-c353-4c37-89fa-e773fe10cea9
 918 ;;; window.el ends here