demo waiting for response

tutorial/23-tutorial.lisp

@@ -0,0 +1,34 @@
+(defpackage #:clog-user
+  (:use #:cl #:clog #:clog-gui)
+  (:export start-tutorial))
+
+(in-package :clog-user)
+
+;; This is a simple demo using semaphores to wait for user input
+(defun ask (obj)
+  (let ((result nil)
+	(hold (bordeaux-threads:make-semaphore))
+	(q-box (create-div obj)))
+    (set-on-click (create-button q-box :content "Yes")
+		  (lambda (obj)
+		    (setf result :yes)
+		    (bordeaux-threads:signal-semaphore hold)))
+    (set-on-click (create-button q-box :content "No")
+		  (lambda (obj)
+		    (setf result :no)
+		    (bordeaux-threads:signal-semaphore hold)))
+    (bordeaux-threads:wait-on-semaphore hold :timeout 10)
+    (destroy q-box)
+    result))
+
+(defun on-new-window (body)
+  (set-on-click (create-button body :content
+			       "Click for my question. You have 10 seconds to answer.")
+		(lambda (obj)
+		  (create-div body :content (ask body))))
+  (run body))
+
+(defun start-tutorial ()
+  "Start turtorial."
+  (initialize #'on-new-window)
+  (open-browser))

tutorial/README.md

@@ -55,3 +55,4 @@ Tutorial Summary
 - 20-tutorial.lisp - New CLOG plugin from JavaScript component
 - 21-tutorial.lisp - New CLOG plugin in Common-Lisp
 - 22-tutorial.lisp - CLOG GUI Menus and Desktop Look and Feel
+- 23-tutorial.lisp - Using semaphores to wait for input