1 files changed, 103 insertions, 0 deletions
diff --git a/chess-module.el b/chess-module.el
new file mode 100644
index 0000000..8d6eed9
--- /dev/null
+++ b/chess-module.el
@@ -0,0 +1,103 @@
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; Basic module support code underlying all chess.el modules
+;;
+;; $Revision$
+
+(defvar chess-module-game nil)
+(defvar chess-module-event-handler nil)
+(defvar chess-module-leader nil)
+
+(make-variable-buffer-local 'chess-module-game)
+(make-variable-buffer-local 'chess-module-event-handler)
+(make-variable-buffer-local 'chess-module-leader)
+
+(chess-message-catalog 'english
+  '((no-such-module . "There is no module named '%s'")))
+
+(defmacro chess-with-current-buffer (buffer &rest body)
+  `(let ((buf ,buffer))
+     (if buf
+	 (with-current-buffer buf
+	   ,@body)
+       ,@body)))
+
+(defun chess-module-create (derived game &optional buffer-name
+				    &rest ctor-args)
+  (let* ((name (symbol-name derived))
+	 (handler (intern-soft (concat name "-handler")))
+	 buffer)
+    (unless handler
+      (chess-error 'no-such-module name))
+    (with-current-buffer (generate-new-buffer (or buffer-name
+						  (format " *%s*" name)))
+      (if (not (apply handler game 'initialize ctor-args))
+	  (ignore
+	   (kill-buffer (current-buffer)))
+	(add-hook 'kill-buffer-hook 'chess-module-destroy nil t)
+	(setq chess-module-event-handler handler)
+	(chess-module-set-game* nil game)
+	(current-buffer)))))
+
+(defun chess-module-game (module)
+  (chess-with-current-buffer module
+    chess-module-game))
+
+(defun chess-module-game-index (module)
+  (chess-with-current-buffer module
+    (chess-game-index chess-module-game)))
+
+(defun chess-module-detach-game (module)
+  (chess-with-current-buffer module
+    (chess-game-remove-hook chess-module-game
+			    'chess-module-event-handler
+			    (or module (current-buffer)))
+    ;; if we are the leader, shutdown the game we were attached to
+    ;; previously
+    (if chess-module-leader
+	(chess-game-run-hooks chess-module-game 'destroy))))
+
+(defun chess-engine-set-game (module game &optional no-setup)
+  (chess-with-current-buffer module
+    (let ((chess-game-inhibit-events no-setup))
+      (chess-game-copy-game chess-module-game game))))
+
+(defun chess-module-set-game* (module game)
+  (chess-with-current-buffer module
+    (assert game)
+    (if chess-module-game
+	(chess-module-detach-game nil))
+    (setq chess-module-game game)
+    (chess-game-add-hook game 'chess-module-event-handler
+			 (or module (current-buffer)))))
+
+(defsubst chess-module-leader-p (module)
+  (chess-with-current-buffer module
+    chess-module-leader))
+
+(defsubst chess-module-set-leader (module)
+  (chess-with-current-buffer module
+    (setq chess-module-leader t)))
+
+(defsubst chess-module-clear-leader (module)
+  (chess-with-current-buffer module
+    (setq chess-module-leader nil)))
+
+(defun chess-module-destroy (&optional module)
+  (interactive)
+  (let ((buf (or module (current-buffer))))
+    (when (buffer-live-p buf)
+      (with-current-buffer buf
+	(remove-hook 'kill-buffer-hook 'chess-module-destroy t))
+      (chess-module-detach-game nil)
+      (kill-buffer buf))))
+
+(defun chess-module-event-handler (game object event &rest args)
+  (with-current-buffer object
+    (apply chess-module-event-handler game event args)
+    (if (eq event 'destroy)
+	(chess-module-destroy nil))))
+
+(provide 'chess-module)
+
+;;; chess-module.el ends here