;;; column-marker.el --- Highlight certain character columns ;; ;; Filename: column-marker.el ;; Description: Highlight certain character columns ;; Author: Rick Bielawski ;; Maintainer: Rick Bielawski ;; Created: Tue Nov 22 10:26:03 2005 ;; Version: 9 ;; Last-Updated: Fri Jan 22 11:28:48 2010 (-0800) ;; By: dradams ;; Update #: 312 ;; Keywords: tools convenience highlight ;; Compatibility: GNU Emacs 21, GNU Emacs 22, GNU Emacs 23 ;; ;; Features that might be required by this library: ;; ;; None ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;; Commentary: ;; ;; Highlights the background at a given character column. ;; ;; Commands `column-marker-1', `column-marker-2', and ;; `column-marker-3' each highlight a given column (using different ;; background colors, by default). ;; ;; - With no prefix argument, each highlights the current column ;; (where the cursor is). ;; ;; - With a non-negative numeric prefix argument, each highlights that ;; column. ;; ;; - With plain `C-u' (no number), each turns off its highlighting. ;; ;; - With `C-u C-u', each turns off all column highlighting. ;; ;; If two commands highlight the same column, the last-issued ;; highlighting command shadows the other - only the last-issued ;; highlighting is seen. If that "topmost" highlighting is then ;; turned off, the other highlighting for that column then shows ;; through. ;; ;; Examples: ;; ;; M-x column-marker-1 highlights the column where the cursor is, in ;; face `column-marker-1'. ;; ;; C-u 70 M-x column-marker-2 highlights column 70 in face ;; `column-marker-2'. ;; ;; C-u 70 M-x column-marker-3 highlights column 70 in face ;; `column-marker-3'. The face `column-marker-2' highlighting no ;; longer shows. ;; ;; C-u M-x column-marker-3 turns off highlighting for column-marker-3, ;; so face `column-marker-2' highlighting shows again for column 70. ;; ;; C-u C-u M-x column-marker-1 (or -2 or -3) erases all column ;; highlighting. ;; ;; These commands use `font-lock-fontify-buffer', so syntax ;; highlighting (`font-lock-mode') must be turned on. There might be ;; a performance impact during refontification. ;; ;; ;; Installation: Place this file on your load path, and put this in ;; your init file (`.emacs'): ;; ;; (require 'column-marker) ;; ;; Other init file suggestions (examples): ;; ;; ;; Highlight column 80 in foo mode. ;; (add-hook 'foo-mode-hook (lambda () (interactive) (column-marker-1 80))) ;; ;; ;; Use `C-c m' interactively to highlight with face `column-marker-1'. ;; (global-set-key [?\C-c ?m] 'column-marker-1) ;; ;; ;; Please report any bugs! ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;; Change log: ;; ;; 2009/12/10 dadams ;; column-marker-internal: Quote the face. Thx to Johan Bockgård. ;; 2009/12/09 dadams ;; column-marker-find: fset a symbol to the function, and return the symbol. ;; 2008/01/21 dadams ;; Renamed faces by dropping suffix "-face". ;; 2006/08/18 dadams ;; column-marker-create: Add newlines to doc-string sentences. ;; 2005/12/31 dadams ;; column-marker-create: Add marker to column-marker-vars inside the defun, ;; so it is done in the right buffer, updating column-marker-vars buffer-locally. ;; column-marker-find: Corrected comment. Changed or to progn for clarity. ;; 2005/12/29 dadams ;; Updated wrt new version of column-marker.el (multi-column characters). ;; Corrected stray occurrences of column-marker-here to column-marker-1. ;; column-marker-vars: Added make-local-variable. ;; column-marker-create: Changed positive to non-negative. ;; column-marker-internal: Turn off marker when col is negative, not < 1. ;; 2005-12-29 RGB ;; column-marker.el now supports multi-column characters. ;; 2005/11/21 dadams ;; Combined static and dynamic. ;; Use separate faces for each marker. Different interactive spec. ;; 2005/10/19 RGB ;; Initial release of column-marker.el. ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;; This program 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 2, or (at your option) ;; any later version. ;; This program 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 this program; see the file COPYING. If not, write to ;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth ;; Floor, Boston, MA 02110-1301, USA. ;; ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;; ;;; Code: ;;;;;;;;;;;;;;;;;;;;;; (defface column-marker-1 '((t (:background "gray"))) "Face used for a column marker. Usually a background color." :group 'faces) (defvar column-marker-1-face 'column-marker-1 "Face used for a column marker. Usually a background color. Changing this directly affects only new markers.") (defface column-marker-2 '((t (:background "cyan3"))) "Face used for a column marker. Usually a background color." :group 'faces) (defvar column-marker-2-face 'column-marker-2 "Face used for a column marker. Usually a background color. Changing this directly affects only new markers." ) (defface column-marker-3 '((t (:background "orchid3"))) "Face used for a column marker. Usually a background color." :group 'faces) (defvar column-marker-3-face 'column-marker-3 "Face used for a column marker. Usually a background color. Changing this directly affects only new markers." ) (defvar column-marker-vars () "List of all internal column-marker variables") (make-variable-buffer-local 'column-marker-vars) ; Buffer local in all buffers. (defmacro column-marker-create (var &optional face) "Define a column marker named VAR. FACE is the face to use. If nil, then face `column-marker-1' is used." (setq face (or face 'column-marker-1)) `(progn ;; define context variable ,VAR so marker can be removed if desired (defvar ,var () "Buffer local. Used internally to store column marker spec.") ;; context must be buffer local since font-lock is (make-variable-buffer-local ',var) ;; Define wrapper function named ,VAR to call `column-marker-internal' (defun ,var (arg) ,(concat "Highlight column with face `" (symbol-name face) "'.\nWith no prefix argument, highlight current column.\n" "With non-negative numeric prefix arg, highlight that column number.\n" "With plain `C-u' (no number), turn off this column marker.\n" "With `C-u C-u' or negative prefix arg, turn off all column-marker highlighting.") (interactive "P") (unless (memq ',var column-marker-vars) (push ',var column-marker-vars)) (cond ((null arg) ; Default: highlight current column. (column-marker-internal ',var (1+ (current-column)) ,face)) ((consp arg) (if (= 4 (car arg)) (column-marker-internal ',var nil) ; `C-u': Remove this column highlighting. (dolist (var column-marker-vars) (column-marker-internal var nil)))) ; `C-u C-u': Remove all column highlighting. ((and (integerp arg) (>= arg 0)) ; `C-u 70': Highlight that column. (column-marker-internal ',var (1+ (prefix-numeric-value arg)) ,face)) (t ; `C-u -40': Remove all column highlighting. (dolist (var column-marker-vars) (column-marker-internal var nil))))))) (defun column-marker-find (col) "Defines a function to locate a character in column COL. Returns the function symbol, named `column-marker-move-to-COL'." (let ((fn-symb (intern (format "column-marker-move-to-%d" col)))) (fset `,fn-symb `(lambda (end) (let ((start (point))) (when (> end (point-max)) (setq end (point-max))) ;; Try to keep `move-to-column' from going backward, though it still can. (unless (< (current-column) ,col) (forward-line 1)) ;; Again, don't go backward. Try to move to correct column. (when (< (current-column) ,col) (move-to-column ,col)) ;; If not at target column, try to move to it. (while (and (< (current-column) ,col) (< (point) end) (= 0 (+ (forward-line 1) (current-column)))) ; Should be bol. (move-to-column ,col)) ;; If at target column, not past end, and not prior to start, ;; then set match data and return t. Otherwise go to start ;; and return nil. (if (and (= ,col (current-column)) (<= (point) end) (> (point) start)) (progn (set-match-data (list (1- (point)) (point))) t) ; Return t. (goto-char start) nil)))) ; Return nil. fn-symb)) (defun column-marker-internal (sym col &optional face) "SYM is the symbol for holding the column marker context. COL is the column in which a marker should be set. Supplying nil or 0 for COL turns off the marker. FACE is the face to use. If nil, then face `column-marker-1' is used." (setq face (or face 'column-marker-1)) (when (symbol-value sym) ; Remove any previously set column marker (font-lock-remove-keywords nil (symbol-value sym)) (set sym nil)) (when (or (listp col) (< col 0)) (setq col nil)) ; Allow nonsense stuff to turn off the marker (when col ; Generate a new column marker (set sym `((,(column-marker-find col) (0 ',face prepend t)))) (font-lock-add-keywords nil (symbol-value sym) t)) (font-lock-fontify-buffer)) ;; If you need more markers you can create your own similarly. ;; All markers can be in use at once, and each is buffer-local, ;; so there is no good reason to define more unless you need more ;; markers in a single buffer. (column-marker-create column-marker-1 column-marker-1-face) (column-marker-create column-marker-2 column-marker-2-face) (column-marker-create column-marker-3 column-marker-3-face) ;;;###autoload (autoload 'column-marker-1 "column-marker" "Highlight a column." t) ;;;;;;;;;;;;;;;;;; (provide 'column-marker) ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ;;; column-marker.el ends here