Rewrote the local minor mode so that it can be

sticky as well and made sticky the default.  Reimplemented the
global minor mode.  Updated the commentary section to document
these changes.
(hl-line-sticky-flag): New user option.
(hl-line-overlay): Made it buffer-local and gave it a docstring.
(global-hl-line-overlay): New variable.
(hl-line-mode): Rewritten to use `hl-line-sticky-flag'.
(hl-line-highlight): Rewritten to use `hl-line-sticky-flag'.
(hl-line-unhighlight): Updated docstring.
(global-hl-line-mode): Implemented directly so that is does not
depend on `hl-line-mode' any more.
(global-hl-line-highlight, global-hl-line-unhighlight): New
functions.

1 files changed, 112 insertions, 45 deletions

diff --git a/lisp/hl-line.el b/lisp/hl-line.el
index 727f859a32e..880ec4ae93e 100644
--- a/lisp/hl-line.el
+++ b/lisp/hl-line.el
@@ -1,6 +1,6 @@
 ;;; hl-line.el --- highlight the current line
 
-;; Copyright (C) 1998, 2000, 2001 Free Software Foundation, Inc.
+;; Copyright (C) 1998, 2000, 2001, 2003 Free Software Foundation, Inc.
 
 ;; Author:  Dave Love <fx@gnu.org>
 ;; Created: 1998-09-13
@@ -25,26 +25,36 @@
 
 ;;; Commentary:
 
-;; Provides a minor mode (toggled by M-x hl-line-mode) and a global minor
-;; mode (toggled by M-x global-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.  It may be useful in "non-text" buffers such as Gnus or
-;; PCL-CVS though.
-
-;; 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.
+;; Provides a buffer-local minor mode (toggled by M-x hl-line-mode)
+;; and a global minor mode (toggled by M-x global-hl-line-mode) to
+;; highlight, on a suitable terminal, the line on which point is.  The
+;; global mode highlights the current line in the selected window only
+;; (except when the minibuffer window is selected).  This was
+;; implemented to satisfy a request for a feature of Lesser Editors.
+;; The local mode is sticky: it highlights the line about the buffer's
+;; point even if the buffer's window is not selected.  Caveat: the
+;; buffer's point might be different from the point of a non-selected
+;; window.  Set the variable `hl-line-sticky-flag' to nil to make the
+;; local mode behave like the global mode.
+
+;; You probably don't really want to use the global mode; 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.  The local mode may be
+;; useful in non-editing buffers such as Gnus or PCL-CVS though.
+
+;; An overlay is used.  In the non-sticky cases, this overlay is
+;; active only on the selected window.  A hook is added to
+;; `post-command-hook' to activate the overlay and move it to the line
+;; about point.  To get the non-sticky behavior, `hl-line-unhighlight'
+;; is added to `pre-command-hook' as well.  This function deactivates
+;; the overlay unconditionally in case the command changes the
+;; selected window.  (It does so rather than keeping track of changes
+;; in the selected window).
+
+;; You could make variable `global-hl-line-mode' buffer-local and set
+;; it to nil to avoid highlighting specific buffers, when the global
+;; mode is used.
 
 ;;; Code:
 
@@ -58,46 +68,103 @@
   :type 'face
   :group 'hl-line)
 
-(defvar hl-line-overlay nil)
+(defcustom hl-line-sticky-flag t
+  "*Non-nil means highlight the current line in all windows.
+Otherwise Hl-Line mode will highlight only in the selected
+window.  Setting this variable takes effect the next time you use
+the command `hl-line-mode' to turn Hl-Line mode on."
+  :type 'boolean
+  :version "21.4"
+  :group 'hl-line)
+
+(defvar hl-line-overlay nil
+  "Overlay used by Hl-Line mode to highlight the current line.")
+(make-variable-buffer-local 'hl-line-overlay)
+
+(defvar global-hl-line-overlay nil
+  "Overlay used by Global-Hl-Line mode to highlight the current line.")
 
 ;;;###autoload
 (define-minor-mode hl-line-mode
-  "Minor mode to highlight the line about point in the current window.
+  "Buffer-local minor mode to highlight the line about point.
 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'."
+
+If `hl-line-sticky-flag' is non-nil, Hl-Line mode highlights the
+line about the buffer's point in all windows.  Caveat: the
+buffer's point might be different from the point of a
+non-selected window.  Hl-Line mode uses the function
+`hl-line-highlight' on `post-command-hook' in this case.
+
+When `hl-line-sticky-flag' is nil, Hl-Line mode highlights the
+line about point in the selected window only.  In this case, it
+uses the function `hl-line-unhighlight' on `pre-command-hook' in
+addition to `hl-line-highlight' on `post-command-hook'."
   nil nil nil
   (if hl-line-mode
       (progn
-	(add-hook 'pre-command-hook #'hl-line-unhighlight nil t)
+        ;; In case `kill-all-local-variables' is called.
+        (add-hook 'change-major-mode-hook #'hl-line-unhighlight nil t)
+        (if hl-line-sticky-flag
+            (remove-hook 'pre-command-hook #'hl-line-unhighlight t)
+          (add-hook 'pre-command-hook #'hl-line-unhighlight nil t))
+        (hl-line-highlight)
 	(add-hook 'post-command-hook #'hl-line-highlight nil t))
+    (remove-hook 'post-command-hook #'hl-line-highlight t)
     (hl-line-unhighlight)
-    (remove-hook 'pre-command-hook #'hl-line-unhighlight t)
-    (remove-hook 'post-command-hook #'hl-line-highlight t)))
-
-;;;###autoload
-(easy-mmode-define-global-mode
- global-hl-line-mode hl-line-mode (lambda () (hl-line-mode 1))
- :group 'hl-line)
+    (remove-hook 'change-major-mode-hook #'hl-line-unhighlight t)
+    (remove-hook 'pre-command-hook #'hl-line-unhighlight t)))
 
 (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		; Might be changed outside the mode function.
-    (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)))))
+  "Active the Hl-Line overlay on the current line."
+  (if hl-line-mode	; Might be changed outside the mode function.
+      (progn
+        (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 (unless hl-line-sticky-flag (selected-window)))
+        (move-overlay hl-line-overlay
+                      (line-beginning-position) (1+ (line-end-position))))
+    (hl-line-unhighlight)))
 
 (defun hl-line-unhighlight ()
-  "Deactivate the Hl-Line overlay on the current line in the current window."
+  "Deactivate the Hl-Line overlay on the current line."
   (if hl-line-overlay
       (delete-overlay hl-line-overlay)))
 
+;;;###autoload
+(define-minor-mode global-hl-line-mode
+  "Global minor mode to highlight the line about point in the current window.
+With ARG, turn Global-Hl-Line mode on if ARG is positive, off otherwise.
+
+Global-Hl-Line mode uses the functions `global-hl-line-unhighlight' and
+`global-hl-line-highlight' on `pre-command-hook' and `post-command-hook'."
+  :global t
+  :group 'hl-line
+  (if global-hl-line-mode
+      (progn
+	(add-hook 'pre-command-hook #'global-hl-line-unhighlight)
+	(add-hook 'post-command-hook #'global-hl-line-highlight))
+    (global-hl-line-unhighlight)
+    (remove-hook 'pre-command-hook #'global-hl-line-unhighlight)
+    (remove-hook 'post-command-hook #'global-hl-line-highlight)))
+
+(defun global-hl-line-highlight ()
+  "Active the Global-Hl-Line overlay on the current line in the current window."
+  (when global-hl-line-mode	; Might be changed outside the mode function.
+    (unless (window-minibuffer-p (selected-window))
+      (unless global-hl-line-overlay
+        (setq global-hl-line-overlay (make-overlay 1 1)) ; to be moved
+        (overlay-put global-hl-line-overlay 'face hl-line-face))
+      (overlay-put global-hl-line-overlay 'window (selected-window))
+      (move-overlay global-hl-line-overlay
+                    (line-beginning-position) (1+ (line-end-position))))))
+
+(defun global-hl-line-unhighlight ()
+  "Deactivate the Global-Hl-Line overlay on the current line."
+  (if global-hl-line-overlay
+      (delete-overlay global-hl-line-overlay)))
+
 (provide 'hl-line)
 
 ;;; hl-line.el ends here