better customizability, using thingsatpt now instead own matcher, fixed fontlocking issue

followcursor-mode.el

@@ -19,7 +19,7 @@
 ;; Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 ;; USA
 
-;; Version: 0.01
+;; Version: 0.02
 ;; Author: T.v.Dein <tlinden@cpan.org>
 ;; Keywords: files
 ;; URL: https://github.com/tlinden/followcursor
@@ -36,6 +36,11 @@
 
 ;;     (followcursor-mode)
 
+;; You  will  be   asked  for  a  `thing-at-point'  to   be  used  for
+;; highlighting,  the  default  being  `lazyword',  which  is  a  mode
+;; indepenent  thing matching  words including  some punctuation.  You
+;; may, however, use any other symbol from the list.
+
 ;; Move around in that buffer as you wish. Whenever `point' is on a
 ;; match, it will be highlighted in both buffers.
 
@@ -44,6 +49,7 @@
 ;;;; Deps
 
 (require 'hi-lock)
+(require 'thingatpt)
 
 ;;;; Customizables
 
@@ -54,15 +60,28 @@
 
 (defcustom followcursor-highlight-there 'highlight-lines-matching-regexp
   ;; also: highlight-regexp
-  "Function used to highlight matching things in there other buffer.")
+  "Function used to highlight matching things in there other buffer."
+  :group 'followcursor)
 
 (defcustom followcursor-highlight-here 'highlight-regexp
-  "Function used to highlight matching things in there current buffer.")
+  "Function used to highlight matching things in there current buffer."
+  :group 'followcursor)
 
-(defcustom followcursor-mark-thing 'followcursor-mark-symbol-lazy
-  "Custom mark function, must set region.
-Use the default or someting like:
-'(lambda() (thing-at-point 'word))")
+(defcustom followcursor-mark-thing 'lazyword
+  "THING at point to highlight.
+
+The default thing, `lazyword', is defined by `followcursor-mode' for
+convenience.
+
+For a list of THINGS, read the documentation of `thing-at-point'."
+  :group 'followcursor)
+
+(defcustom followcursor-available-things
+  '(word lazyword symbol list filename url email line)
+  "THINGs usable with `thing-at-point' to be prompted for.
+
+If you define your own THINGs, add them here."
+  :group 'followcursor)
 
 ;;;; Variables
 
@@ -74,6 +93,14 @@ Use the default or someting like:
  (defvar followcursor-previous-thing nil
    "Buffer local variable storing last thing at point, if any"))
 
+(make-variable-buffer-local
+ (defvar followcursor-font-lock-here nil
+   "font-lock-mode enabled before followcursor-mode?"))
+
+(make-variable-buffer-local
+ (defvar followcursor-font-lock-there nil
+   "font-lock-mode enabled before followcursor-mode?"))
+
 ;;;; Internal Functions
 
 (defun followcursor--setup-ok ()
@@ -81,25 +108,86 @@ Use the default or someting like:
 Return t if there are currently 2 visible windows."
   (eq (count-windows) 2))
 
+(defun followcursor--get-thing-at-point (thing)
+  "Return THING thing-at-point.
+Just a wrapper to omit string properties, if any."
+  (interactive)
+  (thing-at-point thing t))
+
 (defun followcursor--mark-and-highlight (mark-what hl-here hl-there)
   "Marks thing at point using form ''WHAT and highlights using form ''WHICH."
   (interactive)
   (when (followcursor--setup-ok)
-    (let ((thing (funcall mark-what)))
+    (let ((thing (followcursor--get-thing-at-point mark-what)))
       (if thing
         (unless (eq thing followcursor-previous-thing)
           ;; highlight here
           (hi-lock-mode 0)
           (funcall hl-here thing)
+          (font-lock-ensure (point-min) (point-max))
           (other-window 1)
           ;; highlight there
           (hi-lock-mode 0)
           (funcall hl-there thing)
+          (font-lock-ensure (point-min) (point-max))
           ;; go to here buffer
           (other-window 1)
           (setq followcursor-previous-thing thing))
         (followcursor-remove-highlights)))))
 
+(defun followcursor--enable-font-lock ()
+  "Enable font-lock, if not yet enabled.
+Store current state."
+  (unless font-lock-mode
+    (setq followcursor-font-lock-here t)
+    (font-lock-mode))
+  (other-window 1)
+  (unless font-lock-mode
+    (setq followcursor-font-lock-there t)
+    (font-lock-mode))
+  (other-window 1))
+
+(defun followcursor--disable-font-lock ()
+  "Disable font-lock if it were disabled previously."
+  (when followcursor-font-lock-here
+    (font-lock-mode nil)
+    (setq followcursor-font-lock-here nil))
+  (other-window 1)
+  (when followcursor-font-lock-there
+    (font-lock-mode nil)
+    (setq followcursor-font-lock-there nil))
+  (other-window 1))
+
+;;;; Thing-at-Point wrapper[s]
+
+;; Thing[s] used  as the default,  so that  we don' depend  on current
+;; mode's syntax  table. However,  IF the user  want's to  use current
+;; mode, she  can just  select another thing  on startup  or configure
+;; one.
+
+(defun lazyword-bounds-of-lazyword-at-point ()
+  "Return the start and end points of a lazyword at the current point."
+  (let ((pattern "[:alnum:][:punct:]"))
+    (save-excursion
+      (skip-chars-backward pattern)
+      (if (looking-at (concat "[" pattern "]+"))
+          (cons (point) (match-end 0))
+        nil))))
+
+(put 'lazyword 'bounds-of-thing-at-point
+     'lazyword-bounds-of-lazyword-at-point)
+
+(defun followcursor--ask-for-thing-type ()
+  "Ask with completion for THING to be used for highlighting."
+  (interactive)
+  (let ((sym (completing-read
+              (concat "which thing to mark? ["
+                      (symbol-name followcursor-mark-thing) "] ")
+              followcursor-available-things)))
+    (if (string= "" sym)
+        (symbol-name followcursor-mark-thing)
+      sym)))
+
 ;;;; Public Functions
 
 (defun followcursor-remove-highlights ()
@@ -109,39 +197,22 @@ Return t if there are currently 2 visible windows."
   (hi-lock-mode 0)
   (other-window 1))
 
-(defun followcursor-mark-symbol-lazy ()
-  "Mark symbol at point, be tolerant about what constitutes a symbol."
-  (interactive)
-  (let ((thing nil)
-        (beg nil)
-        (end nil))
-    (when (not (looking-at "[ \t\n]"))
-      (save-excursion
-        (unless (looking-back "[ \t\n]")
-          (backward-word)
-          (while (looking-back "[-_\.]")
-            (backward-word)))
-        (setq beg (point))
-        (forward-word)
-        (while (looking-at "[-_\.]")
-          (forward-word))
-        (setq end (point)))
-      (unless (eq beg end)
-        (buffer-substring-no-properties beg end)))))
-
 (defun followcursor-mode-enable ()
   "Enable followcursor-mode."
   (interactive)
   (add-hook 'post-command-hook 'followcursor-mark-when-moved)
   (hi-lock-mode 0)
-  (setq followcursor--last-point (point))
+  (setq followcursor--last-point (point)
+        followcursor-mark-thing (intern (followcursor--ask-for-thing-type)))
+  (followcursor--enable-font-lock)
   (followcursor-mark-when-moved))
 
 (defun followcursor-mode-disable ()
   "Disable followcursor-mode."
   (interactive)
   (remove-hook 'post-command-hook 'followcursor-mark-when-moved)
-  (followcursor-remove-highlights))
+  (followcursor-remove-highlights)
+  (followcursor--disable-font-lock))
 
 ;;;###autoload
 (defun followcursor-mark-when-moved ()