;;; hl-line.el --- highlight the current line ;; Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc. ;; Author: Dave Love <fx@gnu.org> ;; Created: 1998-09-13 ;; Keywords: faces, frames, emulation ;; This file is part of GNU Emacs. ;; GNU Emacs 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. ;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to the ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, ;; Boston, MA 02111-1307, USA. ;;; Commentary: ;; Provides a global minor mode (toggled by M-x hl-line-mode) to ;; highlight, on a suitable terminal, the line in the current window ;; on which point is (except in a minibuffer window). Done to satisfy ;; a request for a feature of Lesser Editors. ;; You probably don't really want this; if the cursor is difficult to ;; spot, try changing its colour, relying on `blink-cursor-mode' or ;; both. The hookery used might affect response noticeably on a slow ;; machine. ;; An overlay is used, active only on the selected window. Hooks are ;; added to `pre-command-hook' and `post-command-hook' to activate and ;; deactivate (by deleting) the overlay. `hl-line-unhighlight', on ;; `pre-command-hook', deactivates it unconditionally in case the ;; command changes the selected window. (It does so rather than ;; keeping track of changes in the selected window). ;; `hl-line-highlight', on `post-command-hook', activates it again ;; across the window width. ;; You could make variable `hl-line-mode' buffer-local to avoid ;; highlighting specific buffers. ;;; Code: (defgroup hl-line nil "Highlight the current line." :version "21.1" :group 'editing) (defcustom hl-line-face 'highlight "Face with which to highlight the current line." :type 'face :group 'hl-line) (defvar hl-line-overlay nil) (defun hl-line-highlight () "Active the Hl-Line overlay on the current line in the current window. \(Unless it's a minibuffer window.)" (when hl-line-mode ; Could be made buffer-local. (unless (window-minibuffer-p (selected-window)) ; silly in minibuffer (unless hl-line-overlay (setq hl-line-overlay (make-overlay 1 1)) ; to be moved (overlay-put hl-line-overlay 'face hl-line-face)) (overlay-put hl-line-overlay 'window (selected-window)) (move-overlay hl-line-overlay (line-beginning-position) (1+ (line-end-position)) (current-buffer))))) (defun hl-line-unhighlight () "Deactivate the Hl-Line overlay on the current line in the current window." (if hl-line-overlay (delete-overlay hl-line-overlay))) ;;;###autoload (define-minor-mode hl-line-mode "Minor mode to highlight the line about point in the current window. With ARG, turn Hl-Line mode on if ARG is positive, off otherwise. Uses functions `hl-line-unhighlight' and `hl-line-highlight' on `pre-command-hook' and `post-command-hook'." nil nil nil (if hl-line-mode (progn (add-hook 'pre-command-hook #'hl-line-unhighlight) (add-hook 'post-command-hook #'hl-line-highlight)) (hl-line-unhighlight) (remove-hook 'pre-command-hook #'hl-line-unhighlight) (remove-hook 'post-command-hook #'hl-line-highlight))) ;;;###autoload (easy-mmode-define-global-mode global-hl-line-mode hl-line-mode hl-line-mode :group 'hl-line) (provide 'hl-line) ;;; hl-line.el ends here