From b8eccd977caae279a6ca4de5de52f1506ca736ff Mon Sep 17 00:00:00 2001
From: Jochen Keil <jochen.keil@gmail.com>
Date: Sat, 3 Jul 2010 09:55:59 +0200
Subject: [PATCH] apply the observer pattern for the gui to get notifications
 from AntView

the update method does the following:
it removes the applet from the list of observers in the Environment
(which updates the graph etc.)
then it sets antView to null since it got disposed; we check somewhere
else for it being null;
if the Environment thread is not null and hasn't terminated yet we send
it an interrupt so it can return gracefully.
when this is done we set antThread to null so we can check for it later
finally we need to reset the button text
and after everything is done we run the gc since it might take a view
seconds before a user wants to start a new computation
---
 src/aco/TspAcoGui.java | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/src/aco/TspAcoGui.java b/src/aco/TspAcoGui.java
index fae428d..f42c2ca 100644
--- a/src/aco/TspAcoGui.java
+++ b/src/aco/TspAcoGui.java
@@ -8,15 +8,21 @@ import java.io.*;
 import java.util.ArrayList;
 import java.util.Collections;
 
-import aco.environment.*;
+import java.util.Observer;
+import java.util.Observable;
+
+import aco.antview.*;
+import aco.mediator.*;
 
 public class TspAcoGui
   extends JFrame
-  implements PopupMenuListener, ItemListener, ActionListener {
+  implements PopupMenuListener, ItemListener, ActionListener, Observer {
 
   static final long serialVersionUID = 100000000L;
 
   protected AntView antView = null;
+  protected ACOMediator acom = null;
+  protected Thread antThread = null;
   protected final String tspdir = "../src/aco/tspproblems/";
 
   String filename;// = "rat99.tsp";
@@ -332,11 +338,30 @@ public class TspAcoGui
           antThread =
             EnvironmentFactory.acs(filename, beta, q, roh, cl, ants, runs);
           break;
-      }
 
     return antThread;
   }
 
+  public void update(Observable o, Object arg) {
+    acom.getEnvironment().deleteObserver(antView);
+    antView = null;
+
+    if (antThread != null) {
+      antThread.interrupt();
+      try {
+        antThread.join();
+      } catch (InterruptedException ie) {
+        System.err.println(ie);
+        return;
+      }
+    }
+
+    antThread = null;
+    startButton.setText("Run selected Algorithm");
+    System.gc();
+
+  }
+
   public static void main(String[] args) {
     new TspAcoGui();
   }
-- 
2.11.4.GIT