Implemented update event

examples/simple.php

@@ -26,22 +26,21 @@ class MyShell extends Shell
         });
         $context->addCommand("mycommand", new MyCommand());
         $this->updatePrompt();
+
+        $this->addListener("update", function() {
+            static $lt;
+            $t = floor(microtime(true));
+            if ($t > $lt) {
+                $lt = $t + 5;
+                echo date("Y-m-d h:i:s")."\n";
+            }
+        });
     }
     
     protected function updatePrompt()
     {
         $this->setPrompt("test[{$this->seq}]: ");
     }
-
-    protected function onUpdate()
-    {
-        static $lt;
-        $t = floor(microtime(true));
-        if ($t > $lt) {
-            $lt = $t + 5;
-            echo date("Y-m-d h:i:s")."\n";
-        }
-    }
     
     protected function onCommand($buffer)
     {