From 3888d7726a9db5918de644e6a6ee5ba938fb0727 Mon Sep 17 00:00:00 2001
From: Thad House <ThadHouse@users.noreply.github.com>
Date: Tue, 6 Sep 2016 21:30:59 -0700
Subject: [PATCH] Adds connection listeners that can be called statically
 (#111)

This way you can have a connection listener before initializing NetworkTables.
---
 .../wpilibj/networktables/NetworkTable.java   | 39 ++++++++++++++++++-
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/java/src/edu/wpi/first/wpilibj/networktables/NetworkTable.java b/java/src/edu/wpi/first/wpilibj/networktables/NetworkTable.java
index 962780308f..b4650fae64 100644
--- a/java/src/edu/wpi/first/wpilibj/networktables/NetworkTable.java
+++ b/java/src/edu/wpi/first/wpilibj/networktables/NetworkTable.java
@@ -223,11 +223,11 @@ public class NetworkTable implements ITable, IRemote {
     return !client;
   }
 
-  private class ListenerBase {
+  private static class ListenerBase {
     public int uid;
   }
 
-  private class ConnectionListenerAdapter extends ListenerBase implements NetworkTablesJNI.ConnectionListenerFunction {
+  private static class ConnectionListenerAdapter extends ListenerBase implements NetworkTablesJNI.ConnectionListenerFunction {
     private final IRemote targetSource;
     private final IRemoteConnectionListener targetListener;
 
@@ -243,6 +243,41 @@ public class NetworkTable implements ITable, IRemote {
         targetListener.disconnectedEx(targetSource, conn);
     }
   }
+  
+  private static IRemote staticRemote = new IRemote() {
+    public void addConnectionListener(IRemoteConnectionListener listener, boolean immediateNotify) {
+      NetworkTable.addGlobalConnectionListener(listener, immediateNotify);
+    }
+    public void removeConnectionListener(IRemoteConnectionListener listener) {
+      NetworkTable.removeGlobalConnectionListener(listener);
+    }
+    public boolean isConnected() {
+      ConnectionInfo[] conns = NetworkTablesJNI.getConnections();
+      return conns.length > 0;
+    }
+    public boolean isServer() {
+      return !client;
+    }
+  };
+  
+  private static final Hashtable<IRemoteConnectionListener,ConnectionListenerAdapter> globalConnectionListenerMap = new Hashtable<IRemoteConnectionListener,ConnectionListenerAdapter>();
+  public static synchronized void addGlobalConnectionListener(IRemoteConnectionListener listener,
+                                                              boolean immediateNotify) {
+    ConnectionListenerAdapter adapter = globalConnectionListenerMap.get(listener);
+    if (adapter != null)
+      throw new IllegalStateException("Cannot add the same listener twice");
+    adapter = new ConnectionListenerAdapter(staticRemote, listener);
+    adapter.uid = NetworkTablesJNI.addConnectionListener(adapter, immediateNotify);
+    globalConnectionListenerMap.put(listener, adapter);
+  }
+
+  public static synchronized void removeGlobalConnectionListener(IRemoteConnectionListener listener) {
+    ConnectionListenerAdapter adapter = globalConnectionListenerMap.get(listener);
+    if (adapter != null) {
+      NetworkTablesJNI.removeConnectionListener(adapter.uid);
+      globalConnectionListenerMap.remove(listener);
+    }
+  }
 
   private final Hashtable<IRemoteConnectionListener,ConnectionListenerAdapter> connectionListenerMap = new Hashtable<IRemoteConnectionListener,ConnectionListenerAdapter>();
   public synchronized void addConnectionListener(IRemoteConnectionListener listener,