* lisp/play/gomoku.el: Don't use intangible property. Use lexical-binding.

(gomoku--last-pos): New var.
(gomoku--intangible-chars): New const.
(gomoku--intangible): New function.
(gomoku-mode): Use it.  Derive from special-mode.
(gomoku-move-up): Adjust line count.
(gomoku-click, gomoku-point-y, gomoku-point-square, gomoku-goto-xy)
(gomoku-plot-square, gomoku-init-display, gomoku-cross-qtuple):
Simplify accordingly.

2 files changed, 68 insertions, 56 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d8b176fad65..9c89b7b1166 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,5 +1,15 @@
 2013-11-25  Stefan Monnier  <monnier@iro.umontreal.ca>
 
+        * play/gomoku.el: Don't use intangible property.  Use lexical-binding.
+        (gomoku--last-pos): New var.
+        (gomoku--intangible-chars): New const.
+        (gomoku--intangible): New function.
+        (gomoku-mode): Use it.  Derive from special-mode.
+        (gomoku-move-up): Adjust line count.
+        (gomoku-click, gomoku-point-y, gomoku-point-square, gomoku-goto-xy)
+        (gomoku-plot-square, gomoku-init-display, gomoku-cross-qtuple):
+        Simplify accordingly.
+
         * frame.el (handle-focus-in, handle-focus-out): Move from frame.c.
         Remove blink-cursor code.
         (blink-cursor-timer-function, blink-cursor-suspend):
diff --git a/lisp/play/gomoku.el b/lisp/play/gomoku.el
index 609585c9522..4a2523ad987 100644
--- a/lisp/play/gomoku.el
+++ b/lisp/play/gomoku.el
@@ -1,4 +1,4 @@
-;;; gomoku.el --- Gomoku game between you and Emacs
+;;; gomoku.el --- Gomoku game between you and Emacs  -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1988, 1994, 1996, 2001-2013 Free Software Foundation,
 ;; Inc.
@@ -176,14 +176,9 @@ One useful value to include is `turn-on-font-lock' to highlight the pieces."
     ("[-|/\\]" 0 (if gomoku-emacs-won 'gomoku-O 'gomoku-X)))
   "Font lock rules for Gomoku.")
 
-(put 'gomoku-mode 'front-sticky
-     (put 'gomoku-mode 'rear-nonsticky '(intangible)))
-(put 'gomoku-mode 'intangible 1)
 ;; This one is for when they set view-read-only to t: Gomoku cannot
 ;; allow View Mode to be activated in its buffer.
-(put 'gomoku-mode 'mode-class 'special)
-
-(define-derived-mode gomoku-mode nil "Gomoku"
+(define-derived-mode gomoku-mode special-mode "Gomoku"
   "Major mode for playing Gomoku against Emacs.
 You and Emacs play in turn by marking a free square.  You mark it with X
 and Emacs marks it with O.  The winner is the first to get five contiguous
@@ -196,7 +191,8 @@ Other useful commands:\n
   (gomoku-display-statistics)
   (make-local-variable 'font-lock-defaults)
   (setq font-lock-defaults '(gomoku-font-lock-keywords t)
-        buffer-read-only t))
+        buffer-read-only t)
+  (add-hook 'post-command-hook #'gomoku--intangible nil t))
 
 ;;;
 ;;; THE BOARD.
@@ -836,8 +832,7 @@ Use \\[describe-mode] for more info."
         (min (max (/ (+ (- (cdr click)
                            gomoku-y-offset
                            1)
-                        (let ((inhibit-point-motion-hooks t))
-                          (count-lines 1 (window-start)))
+                        (count-lines (point-min) (window-start))
                         gomoku-square-height
                         (% gomoku-square-height 2)
                         (/ gomoku-square-height 2))
@@ -961,16 +956,15 @@ If the game is finished, this command requests for another game."
 
 (defun gomoku-point-y ()
   "Return the board row where point is."
-  (let ((inhibit-point-motion-hooks t))
-    (1+ (/ (- (count-lines 1 (point)) gomoku-y-offset (if (bolp) 0 1))
-           gomoku-square-height))))
+  (1+ (/ (- (count-lines (point-min) (point))
+            gomoku-y-offset (if (bolp) 0 1))
+         gomoku-square-height)))
 
 (defun gomoku-point-square ()
   "Return the index of the square point is on."
-  (let ((inhibit-point-motion-hooks t))
-    (gomoku-xy-to-index (1+ (/ (- (current-column) gomoku-x-offset)
-                               gomoku-square-width))
-                        (gomoku-point-y))))
+  (gomoku-xy-to-index (1+ (/ (- (current-column) gomoku-x-offset)
+                             gomoku-square-width))
+                      (gomoku-point-y)))
 
 (defun gomoku-goto-square (index)
   "Move point to square number INDEX."
@@ -978,20 +972,18 @@ If the game is finished, this command requests for another game."
 
 (defun gomoku-goto-xy (x y)
   "Move point to square at X, Y coords."
-  (let ((inhibit-point-motion-hooks t))
-    (goto-char (point-min))
-    (forward-line (+ gomoku-y-offset (* gomoku-square-height (1- y)))))
+  (goto-char (point-min))
+  (forward-line (+ gomoku-y-offset (* gomoku-square-height (1- y))))
   (move-to-column (+ gomoku-x-offset (* gomoku-square-width (1- x)))))
 
 (defun gomoku-plot-square (square value)
   "Draw 'X', 'O' or '.' on SQUARE depending on VALUE, leave point there."
   (or (= value 1)
       (gomoku-goto-square square))
-  (let ((inhibit-read-only t)
-        (inhibit-point-motion-hooks t))
-    (insert-and-inherit (cond ((= value 1) ?X)
-                              ((= value 6) ?O)
-                              (?.)))
+  (let ((inhibit-read-only t))
+    (insert (cond ((= value 1) ?X)
+                  ((= value 6) ?O)
+                  (?.)))
     (and (zerop value)
          (add-text-properties
           (1- (point)) (point)
@@ -1004,8 +996,7 @@ If the game is finished, this command requests for another game."
   "Display an N by M Gomoku board."
   (buffer-disable-undo (current-buffer))
   (let ((inhibit-read-only t)
-        (point 1) opoint
-        (intangible t)
+        (point (point-min)) opoint
         (i m) j x)
     ;; Try to minimize number of chars (because of text properties)
     (setq tab-width
@@ -1014,17 +1005,15 @@ If the game is finished, this command requests for another game."
             (max (/ (+ (% gomoku-x-offset gomoku-square-width)
                        gomoku-square-width 1) 2) 2)))
     (erase-buffer)
-    (newline gomoku-y-offset)
+    (insert-char ?\n gomoku-y-offset)
     (while (progn
              (setq j n
                    x (- gomoku-x-offset gomoku-square-width))
              (while (>= (setq j (1- j)) 0)
-               (insert-char ?\t (/ (- (setq x (+ x gomoku-square-width))
-                                      (current-column))
-                                   tab-width))
-               (insert-char ?  (- x (current-column)))
-               (if (setq intangible (not intangible))
-                   (put-text-property point (point) 'intangible 2))
+               (insert-char ?\t (/ (- (setq x (+ x gomoku-square-width))
+                                      (current-column))
+                                   tab-width))
+               (insert-char ?\s (- x (current-column)))
                (and (zerop j)
                     (= i (- m 2))
                     (progn
@@ -1042,16 +1031,9 @@ If the game is finished, this command requests for another game."
       (if (= i (1- m))
           (setq opoint point))
       (insert-char ?\n gomoku-square-height))
-    (or (eq (char-after 1) ?.)
-        (put-text-property 1 2 'point-entered
-                           (lambda (_x _y) (if (bobp) (forward-char)))))
-    (or intangible
-        (put-text-property point (point) 'intangible 2))
-    (put-text-property point (point) 'point-entered
-                       (lambda (_x _y) (if (eobp) (backward-char))))
-    (put-text-property (point-min) (point) 'category 'gomoku-mode))
+    (insert-char ?\n))
   (gomoku-goto-xy (/ (1+ n) 2) (/ (1+ m) 2)) ; center of the board
-  (sit-for 0))                          ; Display NOW
+  (sit-for 0))                               ; Display NOW
 
 (defun gomoku-display-statistics ()
   "Obnoxiously display some statistics about previous games in mode line."
@@ -1114,8 +1096,7 @@ If the game is finished, this command requests for another game."
   "Cross every square between SQUARE1 and SQUARE2 in the DX, DY direction."
   (save-excursion                       ; Not moving point from last square
     (let ((depl (gomoku-xy-to-index dx dy))
-          (inhibit-read-only t)
-          (inhibit-point-motion-hooks t))
+          (inhibit-read-only t))
       ;; WARNING: this function assumes DEPL > 0 and SQUARE2 > SQUARE1
       (while (/= square1 square2)
         (gomoku-goto-square square1)
@@ -1134,36 +1115,57 @@ If the game is finished, this command requests for another game."
                (setq n (1+ n))
                (forward-line 1)
                (indent-to column)
-               (insert-and-inherit ?|))))
+               (insert ?|))))
           ((= dx -1)                    ; 1st Diagonal
            (indent-to (prog1 (- (current-column) (/ gomoku-square-width 2))
                         (forward-line (/ gomoku-square-height 2))))
-           (insert-and-inherit ?/))
+           (insert ?/))
           (t                            ; 2nd Diagonal
            (indent-to (prog1 (+ (current-column) (/ gomoku-square-width 2))
                         (forward-line (/ gomoku-square-height 2))))
-           (insert-and-inherit ?\\))))))
+           (insert ?\\))))))
   (sit-for 0))                          ; Display NOW
 
 ;;;
 ;;; CURSOR MOTION.
 ;;;
+
+(defvar-local gomoku--last-pos 0)
+
+(defconst gomoku--intangible-chars "- \t\n|/\\\\")
+
+(defun gomoku--intangible ()
+  (when (or (eobp)
+            (save-excursion
+              (not (zerop (skip-chars-forward gomoku--intangible-chars)))))
+    (if (<= gomoku--last-pos (point))   ;Moving forward.
+        (progn
+          (skip-chars-forward gomoku--intangible-chars)
+          (when (eobp)
+            (skip-chars-backward gomoku--intangible-chars)
+            (forward-char -1)))
+      (skip-chars-backward gomoku--intangible-chars)
+      (if (bobp)
+          (skip-chars-forward gomoku--intangible-chars)
+        (forward-char -1))))
+  (setq gomoku--last-pos (point)))
+
 ;; previous-line and next-line don't work right with intangible newlines
 (defun gomoku-move-down ()
   "Move point down one row on the Gomoku board."
   (interactive)
-  (if (< (gomoku-point-y) gomoku-board-height)
-      (let ((column (current-column)))
-        (forward-line gomoku-square-height)
-        (move-to-column column))))
+  (when (< (gomoku-point-y) gomoku-board-height)
+    (let ((column (current-column)))
+      (forward-line gomoku-square-height)
+      (move-to-column column))))
 
 (defun gomoku-move-up ()
   "Move point up one row on the Gomoku board."
   (interactive)
-  (if (> (gomoku-point-y) 1)
-      (let ((column (current-column)))
-        (forward-line (- 1 gomoku-square-height))
-        (move-to-column column))))
+  (when (> (gomoku-point-y) 1)
+    (let ((column (current-column)))
+      (forward-line (- gomoku-square-height))
+      (move-to-column column))))
 
 (defun gomoku-move-ne ()
   "Move point North East on the Gomoku board."