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1 | ;;; hl-line.el --- highlight the current line |
2 | ||
c5967e91 | 3 | ;; Copyright (C) 1998, 2000 Free Software Foundation, Inc. |
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4 | |
5 | ;; Author: Dave Love <fx@gnu.org> | |
6 | ;; Created: 1998-09-13 | |
7 | ;; Keywords: faces, frames | |
8 | ||
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9 | ;; This file is part of GNU Emacs. |
10 | ||
11 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
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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 | ||
643c911e | 16 | ;; GNU Emacs is distributed in the hope that it will be useful, |
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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., 59 Temple Place - Suite 330, | |
24 | ;; Boston, MA 02111-1307, USA. | |
25 | ||
26 | ;;; Commentary: | |
27 | ||
28 | ;; Provides a global minor mode (toggled by M-x hl-line-mode) to | |
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29 | ;; highlight, on a suitable terminal, the line in the current window |
30 | ;; on which point is (except in a minibuffer window). Done to satisfy | |
31 | ;; a request for a feature of Lesser Editors. | |
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32 | |
33 | ;; You probably don't really want this; if the cursor is difficult to | |
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34 | ;; spot, try changing its colour or relying on `blink-cursor-mode' The |
35 | ;; hookery involved here might slow Emacs noticeably on a slow | |
36 | ;; machine. | |
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37 | |
38 | ;; An overlay is used, active only on the selected window. Hooks are | |
39 | ;; added to `pre-command-hook' and `post-command-hook' to activate and | |
40 | ;; deactivate (by deleting) the overlay. `hl-line-unhighlight', on | |
41 | ;; `pre-command-hook', deactivates it unconditionally in case the | |
42 | ;; command changes the selected window. (It does so rather than | |
43 | ;; keeping track of changes in the selected window). | |
44 | ;; `hl-line-highlight', on `post-command-hook', activates it again | |
45 | ;; across the window width. | |
46 | ||
47 | ;;; Code: | |
48 | ||
49 | (defgroup hl-line nil | |
50 | "Highliight the current line." | |
eee06d26 | 51 | :version "21.1" |
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52 | :group 'editing) |
53 | ||
ceafc2fa | 54 | ;;;###autoload |
798330fe | 55 | (defcustom hl-line-mode nil |
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56 | "Toggle Hl-Line mode. |
57 | Setting this variable directly does not take effect; | |
58 | use either \\[customize] or the function `hl-line-mode'." | |
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59 | :set (lambda (symbol value) |
60 | (hl-line-mode (or value 0))) | |
61 | :initialize 'custom-initialize-default | |
62 | :type 'boolean | |
63 | :group 'hl-line | |
64 | :require 'hl-line) | |
65 | ||
66 | (defcustom hl-line-face 'highlight | |
67 | "Face with which to highlight the current line." | |
68 | :type 'face | |
69 | :group 'hl-line) | |
70 | ||
71 | (defvar hl-line-overlay nil) | |
72 | (make-variable-buffer-local 'hl-line-overlay) | |
73 | ||
74 | (defun hl-line-highlight () | |
75 | "Active the Hl-Line overlay on the current line in the current window. | |
76 | \(Unless it's a minibuffer window.)" | |
77 | (unless (window-minibuffer-p (selected-window)) ; silly in minibuffer | |
78 | (unless hl-line-overlay ; new overlay for this buffer | |
79 | (setq hl-line-overlay (make-overlay 1 1)) ; to be moved | |
80 | (overlay-put hl-line-overlay 'face hl-line-face)) | |
81 | (overlay-put hl-line-overlay 'window (selected-window)) | |
82 | (move-overlay hl-line-overlay | |
83 | (line-beginning-position) (1+ (line-end-position))))) | |
84 | ||
85 | (defun hl-line-unhighlight () | |
86 | "Deactivate the Hl-Line overlay on the current line in the current window." | |
87 | (if hl-line-overlay | |
88 | (delete-overlay hl-line-overlay))) | |
89 | ||
ceafc2fa | 90 | ;;;###autoload |
798330fe | 91 | (defun hl-line-mode (&optional arg) |
c5967e91 | 92 | "Global minor mode to highlight the line about point in the current window. |
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93 | |
94 | With ARG, turn Hl-Line mode on if ARG is positive, off otherwise. | |
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95 | Uses functions `hl-line-unhighlight' and `hl-line-highlight' on |
96 | `pre-command-hook' and `post-command-hook'." | |
97 | (interactive "P") | |
98 | (setq hl-line-mode (if (null arg) | |
99 | (not hl-line-mode) | |
100 | (> (prefix-numeric-value arg) 0))) | |
101 | (cond (hl-line-mode | |
102 | (add-hook 'pre-command-hook #'hl-line-unhighlight) | |
103 | (add-hook 'post-command-hook #'hl-line-highlight)) | |
104 | (t | |
105 | (hl-line-unhighlight) | |
106 | (remove-hook 'pre-command-hook #'hl-line-unhighlight) | |
107 | (remove-hook 'post-command-hook #'hl-line-highlight))) | |
108 | (if (interactive-p) | |
109 | (message "Hl-Line mode %sabled" (if hl-line-mode "en" "dis")))) | |
110 | ||
111 | (provide 'hl-line) | |
112 | ||
113 | ;;; hl-line.el ends here |