lisp/rsz-mini.el

   1 ;;; rsz-mini.el --- dynamically resize minibuffer to display entire contents
   2
   3 ;; Copyright (C) 1990, 1993, 1994, 1995 Free Software Foundation, Inc.
   4
   5 ;; Author: Noah Friedman <friedman@prep.ai.mit.edu>
   6 ;;         Roland McGrath <roland@prep.ai.mit.edu>
   7 ;; Maintainer: friedman@prep.ai.mit.edu
   8 ;; Keywords: minibuffer, window, frame, display
   9 ;; Status: Known to work in FSF GNU Emacs 19.26 and later.
  10 ;; $Id: rsz-mini.el,v 1.10 1996/01/09 23:21:29 kwzh Exp erik $
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software; you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation; either version 2, or (at your option)
  17 ;; any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  26 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  27 ;; Boston, MA 02111-1307, USA.
  28
  29 ;;; Commentary:
  30
  31 ;; This package allows the entire contents (or as much as possible) of the
  32 ;; minibuffer to be visible at once when typing.  As the end of a line is
  33 ;; reached, the minibuffer will resize itself.  When the user is done
  34 ;; typing, the minibuffer will return to its original size.
  35
  36 ;; In window systems where it is possible to have a frame in which the
  37 ;; minibuffer is the only window, the frame itself can be resized.  In FSF
  38 ;; GNU Emacs 19.22 and earlier, the frame may not be properly returned to
  39 ;; its original size after it ceases to be active because
  40 ;; `minibuffer-exit-hook' didn't exist until version 19.23.
  41 ;;
  42 ;; Prior to Emacs 19.26, minibuffer-exit-hook wasn't called after exiting
  43 ;; from the minibuffer by hitting the quit char.  That meant that the
  44 ;; frame size restoration function wasn't being called in that case.  In
  45 ;; 19.26 or later, minibuffer-exit-hook should be called anyway.
  46
  47 ;; Note that the minibuffer and echo area are not the same!  They simply
  48 ;; happen to occupy roughly the same place on the frame.  Messages put in
  49 ;; the echo area will not cause any resizing by this package.
  50
  51 ;; This package is considered a minor mode but it doesn't put anything in
  52 ;; minor-mode-alist because this mode is specific to the minibuffer, which
  53 ;; has no mode line.
  54
  55 ;; To enable or disable this mode, use M-x resize-minibuffer-mode.
  56
  57 ;;; Code:
  58
  59 \f
  60 ;;;###autoload
  61 (defvar resize-minibuffer-mode nil
  62   "*If non-`nil', resize the minibuffer so its entire contents are visible.")
  63
  64 ;;;###autoload
  65 (defvar resize-minibuffer-window-max-height nil
  66   "*Maximum size the minibuffer window is allowed to become.
  67 If less than 1 or not a number, the limit is the height of the frame in
  68 which the active minibuffer window resides.")
  69
  70 ;;;###autoload
  71 (defvar resize-minibuffer-window-exactly t
  72   "*Allow making minibuffer exactly the size to display all its contents.
  73 If `nil', the minibuffer window can temporarily increase in size but
  74 never get smaller while it is active.  Any other value allows exact
  75 resizing.")
  76
  77 ;;;###autoload
  78 (defvar resize-minibuffer-frame nil
  79   "*Allow changing the frame height of minibuffer frames.
  80 If non-`nil' and the active minibuffer is the sole window in its frame,
  81 allow changing the frame height.")
  82
  83 ;;;###autoload
  84 (defvar resize-minibuffer-frame-max-height nil
  85   "*Maximum size the minibuffer frame is allowed to become.
  86 If less than 1 or not a number, there is no limit.")
  87
  88 ;;;###autoload
  89 (defvar resize-minibuffer-frame-exactly t
  90   "*Allow making minibuffer frame exactly the size to display all its contents.
  91 If `nil', the minibuffer frame can temporarily increase in size but
  92 never get smaller while it is active.  Any other value allows exact
  93 resizing.")
  94
  95 ;; Variable used to store the height of the minibuffer frame
  96 ;; on entry, so it can be restored on exit.  It is made local before it is
  97 ;; modified.  Do not use it yourself.
  98 (defvar resize-minibuffer-frame-original-height nil)
  99
 100 \f
 101 ;;;###autoload
 102 (defun resize-minibuffer-mode (&optional prefix)
 103   "Enable or disable resize-minibuffer mode.
 104 A negative prefix argument disables this mode.  A positive argument or
 105 argument of 0 enables it.
 106
 107 When this minor mode is enabled, the minibuffer is dynamically resized to
 108 contain the entire region of text put in it as you type.
 109
 110 The variable `resize-minibuffer-mode' is set to t or nil depending on
 111 whether this mode is active or not.
 112
 113 The maximum height to which the minibuffer can grow is controlled by the
 114 variable `resize-minibuffer-window-max-height'.
 115
 116 The variable `resize-minibuffer-window-exactly' determines whether the
 117 minibuffer window should ever be shrunk to make it no larger than needed to
 118 display its contents.
 119
 120 When using a window system, it is possible for a minibuffer to be the sole
 121 window in a frame.  Since that window is already its maximum size, the only
 122 way to make more text visible at once is to increase the size of the frame.
 123 The variable `resize-minibuffer-frame' controls whether this should be
 124 done.  The variables `resize-minibuffer-frame-max-height' and
 125 `resize-minibuffer-frame-exactly' are analogous to their window
 126 counterparts."
 127   (interactive "p")
 128   (or prefix (setq prefix 0))
 129   (cond
 130    ((>= prefix 0)
 131     (setq resize-minibuffer-mode t))
 132    (t
 133     (setq resize-minibuffer-mode nil))))
 134
 135 (defun resize-minibuffer-setup ()
 136   (cond
 137    (resize-minibuffer-mode
 138     (cond
 139      ((and window-system
 140            (eq 'only (cdr (assq 'minibuffer (frame-parameters)))))
 141       ;; Checking for resize-minibuffer-frame is done outside the cond
 142       ;; predicate because that should always be t if this is a minibuffer
 143       ;; frame; it just shouldn't do anything if this flag is nil.
 144       (and resize-minibuffer-frame
 145            (progn
 146              ;; Can't trust the height stored in minibuffer-frame-alist
 147              ;; since the frame can be resized by the window manager and
 148              ;; that variable isn't updated.
 149              (make-local-variable 'resize-minibuffer-frame-original-height)
 150              (setq resize-minibuffer-frame-original-height (frame-height))
 151
 152              (make-local-hook 'post-command-hook)
 153              (add-hook 'post-command-hook 'resize-minibuffer-frame 'append t)
 154
 155              (make-local-hook 'minibuffer-exit-hook)
 156              (add-hook 'minibuffer-exit-hook 'resize-minibuffer-frame-restore
 157                        nil t)
 158
 159              (resize-minibuffer-frame))))
 160      (t
 161       (make-local-variable 'post-command-hook)
 162       ;; Copy this because add-hook modifies the list structure.
 163       (setq post-command-hook (copy-sequence post-command-hook))
 164       (add-hook 'post-command-hook 'resize-minibuffer-window 'append)
 165
 166       (make-local-variable 'minibuffer-exit-hook)
 167       (add-hook 'minibuffer-exit-hook 'resize-minibuffer-window-restore)
 168
 169       (resize-minibuffer-window))))))
 170
 171 (defun resize-minibuffer-count-window-lines (&optional start end)
 172   "Return number of window lines occupied by text in region.
 173 The number of window lines may be greater than the number of actual lines
 174 in the buffer if any wrap on the display due to their length.
 175
 176 Optional arguments START and END default to point-min and point-max,
 177 respectively."
 178   (or start (setq start (point-min)))
 179   (or end   (setq end   (point-max)))
 180   (if (= start end)
 181       0
 182     (save-excursion
 183       (save-restriction
 184         (widen)
 185         (narrow-to-region start end)
 186         (goto-char start)
 187         (vertical-motion (buffer-size))))))
 188
 189 \f
 190 ;; Resize the minibuffer window to contain the minibuffer's contents.
 191 (defun resize-minibuffer-window ()
 192   (and (eq (selected-window) (minibuffer-window))
 193        (let ((height (window-height))
 194              (lines (1+ (resize-minibuffer-count-window-lines))))
 195          (and (numberp resize-minibuffer-window-max-height)
 196               (> resize-minibuffer-window-max-height 0)
 197               (setq lines (min lines resize-minibuffer-window-max-height)))
 198          (or (if resize-minibuffer-window-exactly
 199                  (= lines height)
 200                (<= lines height))
 201              (enlarge-window (- lines height))))))
 202
 203 ;; This resizes the minibuffer back to one line as soon as it is exited
 204 ;; (e.g. when the user hits RET).  This way, subsequent messages put in the
 205 ;; echo area aren't cluttered with leftover minibuffer text.
 206 ;; It should be called by minibuffer-exit-hook.
 207 ;;
 208 ;; Note that because it calls sit-for to force a screen update, strange
 209 ;; things may happen in the minibuffer, such as unexpanded partial
 210 ;; completions by complete.el showing their completion.
 211 ;; If this bothers you, just redefine this function to do nothing, in, say,
 212 ;; your after-load-alist.  Perhaps there should be an option variable,
 213 ;; but I don't know if there's really any demand for it.
 214 ;; (Clobbering this definition is harmless because eventually emacs restores
 215 ;; its idea of the minibuffer window size when the minibuffer isn't in use
 216 ;; anyway; this is just a kludge because of the timing for that update).
 217 (defun resize-minibuffer-window-restore ()
 218   (cond
 219    ((not (eq (minibuffer-window) (selected-window))))
 220    ((> (window-height) 1)
 221     (enlarge-window (- 1 (window-height)))
 222     (sit-for 0))))
 223
 224 \f
 225 ;; Resize the minibuffer frame to contain the minibuffer's contents.
 226 ;; The minibuffer frame must be the current frame.
 227 (defun resize-minibuffer-frame ()
 228   (let ((height (frame-height))
 229         (lines (1+ (resize-minibuffer-count-window-lines))))
 230     (and (numberp resize-minibuffer-frame-max-height)
 231          (> resize-minibuffer-frame-max-height 0)
 232          (setq lines (min lines resize-minibuffer-frame-max-height)))
 233     (cond
 234      ((> lines height)
 235       (set-frame-size (selected-frame) (frame-width) lines))
 236      ((and resize-minibuffer-frame-exactly
 237            (> height resize-minibuffer-frame-original-height)
 238            (< lines height))
 239       (set-frame-size (selected-frame) (frame-width) lines)))))
 240
 241 ;; Restore the original height of the frame.
 242 ;; resize-minibuffer-frame-original-height is set in
 243 ;; resize-minibuffer-setup.
 244 (defun resize-minibuffer-frame-restore ()
 245   (set-frame-size (selected-frame)
 246                   (frame-width)
 247                   resize-minibuffer-frame-original-height))
 248
 249 \f
 250 (provide 'rsz-mini)
 251
 252 (add-hook 'minibuffer-setup-hook 'resize-minibuffer-setup)
 253 (resize-minibuffer-mode)
 254
 255 ;; rsz-mini.el ends here