IDE network discovery now reacts to new networks: it monitors available IP addresses and, when one is added, it starts listening to bonjours coming from it

app/src/cc/arduino/packages/Discovery.java

@@ -23,7 +23,7 @@ public interface Discovery {
   /**
    * Stop discovery service
    */
-  public void stop();
+  public void stop() throws Exception;
 
   /**
    * Return the list of discovered ports.

app/src/cc/arduino/packages/DiscoveryManager.java

@@ -1,12 +1,12 @@
 package cc.arduino.packages;
 
-import static processing.app.I18n._;
+import cc.arduino.packages.discoverers.NetworkDiscovery;
+import cc.arduino.packages.discoverers.SerialDiscovery;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import cc.arduino.packages.discoverers.NetworkDiscovery;
-import cc.arduino.packages.discoverers.SerialDiscovery;
+import static processing.app.I18n._;
 
 public class DiscoveryManager {
 
@@ -25,7 +25,7 @@ public class DiscoveryManager {
         e.printStackTrace();
       }
     }
-    
+
     Runtime.getRuntime().addShutdownHook(closeHook);
   }
 
@@ -39,8 +39,13 @@ public class DiscoveryManager {
   private Thread closeHook = new Thread(new Runnable() {
     @Override
     public void run() {
-      for (Discovery d : discoverers)
-        d.stop();
+      for (Discovery d : discoverers) {
+        try {
+          d.stop();
+        } catch (Exception e) {
+          e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.
+        }
+      }
     }
   });
 }

app/src/cc/arduino/packages/discoverers/NetworkDiscovery.java

@@ -2,6 +2,7 @@ package cc.arduino.packages.discoverers;
 
 import cc.arduino.packages.BoardPort;
 import cc.arduino.packages.Discovery;
+import cc.arduino.packages.discoverers.network.NetworkChecker;
 import processing.app.Base;
 import processing.app.helpers.PreferencesMap;
 import processing.app.zeroconf.jmdns.ArduinoDNSTaskStarter;
@@ -12,17 +13,18 @@ import java.io.IOException;
 import java.net.Inet4Address;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
+import java.util.*;
 
-public class NetworkDiscovery implements Discovery, ServiceListener {
+public class NetworkDiscovery implements Discovery, ServiceListener, cc.arduino.packages.discoverers.network.NetworkTopologyListener {
 
+  private Timer timer;
   private List<BoardPort> ports;
+  private final Map<InetAddress, JmDNS> mappedJmDNSs;
 
   public NetworkDiscovery() {
     DNSTaskStarter.Factory.setClassDelegate(new ArduinoDNSTaskStarter());
     this.ports = new ArrayList<BoardPort>();
+    this.mappedJmDNSs = new Hashtable<InetAddress, JmDNS>();
   }
 
   @Override
@@ -56,21 +58,14 @@ public class NetworkDiscovery implements Discovery, ServiceListener {
 
   @Override
   public void start() throws IOException {
-    for (InetAddress addr : NetworkTopologyDiscovery.Factory.getInstance().getInetAddresses()) {
-      JmDNS jmDNS = JmDNS.create(addr);
-      jmDNS.addServiceListener("_arduino._tcp.local.", this);
-    }
+    this.timer = new Timer(this.getClass().getName() + " timer");
+    new NetworkChecker(this, NetworkTopologyDiscovery.Factory.getInstance()).start(timer);
   }
 
   @Override
-  public void stop() {
-    // Removed cleanup: is extremely slow on closing
-
-    // try {
-    // jmDNS.close();
-    // } catch (IOException e) {
-    // e.printStackTrace();
-    // }
+  public void stop() throws IOException {
+    timer.purge();
+    // we don't close each JmDNS instance as it's too slow
   }
 
   @Override
@@ -130,4 +125,29 @@ public class NetworkDiscovery implements Discovery, ServiceListener {
     }
   }
 
+  @Override
+  public void inetAddressAdded(InetAddress address) {
+    if (mappedJmDNSs.containsKey(address)) {
+      return;
+    }
+    try {
+      JmDNS jmDNS = JmDNS.create(address);
+      jmDNS.addServiceListener("_arduino._tcp.local.", this);
+      mappedJmDNSs.put(address, jmDNS);
+    } catch (Exception e) {
+      e.printStackTrace();
+    }
+  }
+
+  @Override
+  public void inetAddressRemoved(InetAddress address) {
+    JmDNS jmDNS = mappedJmDNSs.remove(address);
+    if (jmDNS != null) {
+      try {
+        jmDNS.close();
+      } catch (IOException e) {
+        e.printStackTrace();
+      }
+    }
+  }
 }

app/src/cc/arduino/packages/discoverers/network/NetworkChecker.java

@@ -0,0 +1,46 @@
+package cc.arduino.packages.discoverers.network;
+
+import javax.jmdns.NetworkTopologyDiscovery;
+import java.net.InetAddress;
+import java.util.*;
+
+public class NetworkChecker extends TimerTask {
+
+  private final NetworkTopologyListener topologyListener;
+  private final NetworkTopologyDiscovery topology;
+
+  private Set<InetAddress> knownAddresses;
+
+  public NetworkChecker(NetworkTopologyListener topologyListener, NetworkTopologyDiscovery topology) {
+    super();
+    this.topologyListener = topologyListener;
+    this.topology = topology;
+    this.knownAddresses = Collections.synchronizedSet(new HashSet<InetAddress>());
+  }
+
+  public void start(Timer timer) {
+    timer.schedule(this, 0, 3000);
+  }
+
+  @Override
+  public void run() {
+    try {
+      InetAddress[] curentAddresses = topology.getInetAddresses();
+      Set<InetAddress> current = new HashSet<InetAddress>(curentAddresses.length);
+      for (InetAddress address : curentAddresses) {
+        current.add(address);
+        if (!knownAddresses.contains(address)) {
+          topologyListener.inetAddressAdded(address);
+        }
+      }
+      for (InetAddress address : knownAddresses) {
+        if (!current.contains(address)) {
+          topologyListener.inetAddressRemoved(address);
+        }
+      }
+      knownAddresses = current;
+    } catch (Exception e) {
+      e.printStackTrace();
+    }
+  }
+}

app/src/cc/arduino/packages/discoverers/network/NetworkTopologyListener.java

@@ -0,0 +1,11 @@
+package cc.arduino.packages.discoverers.network;
+
+import java.net.InetAddress;
+
+public interface NetworkTopologyListener {
+
+  void inetAddressAdded(InetAddress address);
+
+  void inetAddressRemoved(InetAddress address);
+
+}