lisp/rect.el

   1 ;; Rectangle functions for GNU Emacs.
   2 ;; Copyright (C) 1985 Free Software Foundation, Inc.
   3
   4 ;; This file is part of GNU Emacs.
   5
   6 ;; GNU Emacs is free software; you can redistribute it and/or modify
   7 ;; it under the terms of the GNU General Public License as published by
   8 ;; the Free Software Foundation; either version 1, or (at your option)
   9 ;; any later version.
  10
  11 ;; GNU Emacs is distributed in the hope that it will be useful,
  12 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 ;; GNU General Public License for more details.
  15
  16 ;; You should have received a copy of the GNU General Public License
  17 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  18 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20
  21 (defun operate-on-rectangle (function start end coerce-tabs)
  22   "Call FUNCTION for each line of rectangle with corners at START, END.
  23 If COERCE-TABS is non-nil, convert multi-column characters
  24 that span the starting or ending columns on any line
  25 to multiple spaces before calling FUNCTION.
  26 FUNCTION is called with three arguments:
  27  position of start of segment of this line within the rectangle,
  28  number of columns that belong to rectangle but are before that position,
  29  number of columns that belong to rectangle but are after point.
  30 Point is at the end of the segment of this line within the rectangle."
  31   (let (startcol startlinepos endcol endlinepos)
  32     (save-excursion
  33      (goto-char start)
  34      (setq startcol (current-column))
  35      (beginning-of-line)
  36      (setq startlinepos (point)))
  37     (save-excursion
  38      (goto-char end)
  39      (setq endcol (current-column))
  40      (forward-line 1)
  41      (setq endlinepos (point-marker)))
  42     (if (< endcol startcol)
  43         (let ((tem startcol))
  44           (setq startcol endcol endcol tem)))
  45     (if (/= endcol startcol)
  46         (save-excursion
  47          (goto-char startlinepos)
  48          (while (< (point) endlinepos)
  49            (let (startpos begextra endextra)
  50              (move-to-column startcol)
  51              (and coerce-tabs
  52                   (> (current-column) startcol)
  53                   (rectangle-coerce-tab startcol))
  54              (setq begextra (- (current-column) startcol))
  55              (setq startpos (point))
  56              (move-to-column endcol)
  57              (if (> (current-column) endcol)
  58                  (if coerce-tabs
  59                      (rectangle-coerce-tab endcol)
  60                    (forward-char -1)))
  61              (setq endextra (- endcol (current-column)))
  62              (if (< begextra 0)
  63                  (setq endextra (+ endextra begextra)
  64                        begextra 0))
  65              (funcall function startpos begextra endextra))
  66            (forward-line 1))))
  67     (- endcol startcol)))
  68
  69 (defun delete-rectangle-line (startdelpos ignore ignore)
  70   (delete-region startdelpos (point)))
  71
  72 (defun delete-extract-rectangle-line (startdelpos begextra endextra)
  73   (save-excursion
  74    (extract-rectangle-line startdelpos begextra endextra))
  75   (delete-region startdelpos (point)))
  76
  77 (defun extract-rectangle-line (startdelpos begextra endextra)
  78   (let ((line (buffer-substring startdelpos (point)))
  79         (end (point)))
  80     (goto-char startdelpos)
  81     (while (search-forward "\t" end t)
  82       (let ((width (- (current-column)
  83                       (save-excursion (forward-char -1)
  84                                       (current-column)))))
  85         (setq line (concat (substring line 0 (- (point) end 1))
  86                            (spaces-string width)
  87                            (substring line (+ (length line) (- (point) end)))))))
  88     (if (or (> begextra 0) (> endextra 0))
  89         (setq line (concat (spaces-string begextra)
  90                            line
  91                            (spaces-string endextra))))
  92     (setq lines (cons line lines))))
  93
  94 (defconst spaces-strings
  95   '["" " " "  " "   " "    " "     " "      " "       " "        "])
  96
  97 (defun spaces-string (n)
  98   (if (<= n 8) (aref spaces-strings n)
  99     (let ((val ""))
 100       (while (> n 8)
 101         (setq val (concat "        " val)
 102               n (- n 8)))
 103       (concat val (aref spaces-strings n)))))
 104
 105 ;;;###autoload
 106 (defun delete-rectangle (start end)
 107   "Delete (don't save) text in rectangle with point and mark as corners.
 108 The same range of columns is deleted in each line starting with the line
 109 where the region begins and ending with the line where the region ends."
 110   (interactive "r")
 111   (operate-on-rectangle 'delete-rectangle-line start end t))
 112
 113 ;;;###autoload
 114 (defun delete-extract-rectangle (start end)
 115   "Delete contents of rectangle and return it as a list of strings.
 116 Arguments START and END are the corners of the rectangle.
 117 The value is list of strings, one for each line of the rectangle."
 118   (let (lines)
 119     (operate-on-rectangle 'delete-extract-rectangle-line
 120                           start end t)
 121     (nreverse lines)))
 122
 123 ;;;###autoload
 124 (defun extract-rectangle (start end)
 125   "Return contents of rectangle with corners at START and END.
 126 Value is list of strings, one for each line of the rectangle."
 127   (let (lines)
 128     (operate-on-rectangle 'extract-rectangle-line start end nil)
 129     (nreverse lines)))
 130
 131 (defvar killed-rectangle nil
 132   "Rectangle for yank-rectangle to insert.")
 133
 134 ;;;###autoload
 135 (defun kill-rectangle (start end)
 136   "Delete rectangle with corners at point and mark; save as last killed one.
 137 Calling from program, supply two args START and END, buffer positions.
 138 But in programs you might prefer to use `delete-extract-rectangle'."
 139   (interactive "r")
 140   (setq killed-rectangle (delete-extract-rectangle start end)))
 141
 142 ;;;###autoload
 143 (defun yank-rectangle ()
 144   "Yank the last killed rectangle with upper left corner at point."
 145   (interactive)
 146   (insert-rectangle killed-rectangle))
 147
 148 ;;;###autoload
 149 (defun insert-rectangle (rectangle)
 150   "Insert text of RECTANGLE with upper left corner at point.
 151 RECTANGLE's first line is inserted at point, its second
 152 line is inserted at a point vertically under point, etc.
 153 RECTANGLE should be a list of strings."
 154   (let ((lines rectangle)
 155         (insertcolumn (current-column))
 156         (first t))
 157     (while lines
 158       (or first
 159           (progn
 160            (forward-line 1)
 161            (or (bolp) (insert ?\n))
 162            (move-to-column insertcolumn)
 163            (if (> (current-column) insertcolumn)
 164                (rectangle-coerce-tab insertcolumn))
 165            (if (< (current-column) insertcolumn)
 166                (indent-to insertcolumn))))
 167       (setq first nil)
 168       (insert (car lines))
 169       (setq lines (cdr lines)))))
 170
 171 ;;;###autoload
 172 (defun open-rectangle (start end)
 173   "Blank out rectangle with corners at point and mark, shifting text right.
 174 The text previously in the region is not overwritten by the blanks,
 175 but insted winds up to the right of the rectangle."
 176   (interactive "r")
 177   (operate-on-rectangle 'open-rectangle-line start end nil))
 178
 179 (defun open-rectangle-line (startpos begextra endextra)
 180   (let ((column (+ (current-column) begextra endextra)))
 181     (goto-char startpos)
 182     (let ((ocol (current-column)))
 183       (skip-chars-forward " \t")
 184       (setq column (+ column (- (current-column) ocol))))
 185     (delete-region (point)
 186                    (progn (skip-chars-backward " \t")
 187                           (point)))
 188     (indent-to column)))
 189
 190 ;;;###autoload
 191 (defun clear-rectangle (start end)
 192   "Blank out rectangle with corners at point and mark.
 193 The text previously in the region is overwritten by the blanks.
 194 When called from a program, requires two args which specify the corners."
 195   (interactive "r")
 196   (operate-on-rectangle 'clear-rectangle-line start end t))
 197
 198 (defun clear-rectangle-line (startpos begextra endextra)
 199   (skip-chars-forward " \t")
 200   (let ((column (+ (current-column) endextra)))
 201     (delete-region (point)
 202                    (progn (goto-char startpos)
 203                           (skip-chars-backward " \t")
 204                           (point)))
 205     (indent-to column)))
 206
 207 (defun rectangle-coerce-tab (column)
 208   (let ((aftercol (current-column))
 209         (indent-tabs-mode nil))
 210     (delete-char -1)
 211     (indent-to aftercol)
 212     (backward-char (- aftercol column))))