--- a/src/main/java/jp/ac/u_ryukyu/treevnc/TreeRFBProto.java	Wed Aug 03 19:09:11 2016 +0900
+++ b/src/main/java/jp/ac/u_ryukyu/treevnc/TreeRFBProto.java	Wed Aug 03 20:58:36 2016 +0900
@@ -43,6 +43,7 @@
     private Deflater deflater = new Deflater();
     ViewerInterface viewer;
     private short id = 0;  // my tree node id ( = 0 in root ), -1 means no parent
+    private short sharingId = -1; // VNCServer's id. this is used control visivility
     private TreeVncCommandChannelListener acceptThread;
     private TreeRootFinderListener getCast;
     private CreateConnectionParam cp;
@@ -756,8 +757,8 @@
     }
 
     public int getNewNodeId () {
-        return uniqueNodeId++;
-    }
+        return ++uniqueNodeId;
+    } // 0 is reserved for root
 
     /**
      * change VNCServer is called when host change.
@@ -912,8 +913,16 @@
         multicastqueue.put(errorAnnounce);
     }
 
-
     public void setConnectionPresenter(ConnectionPresenter connectionPresenter) {
         this.connectionPresenter = connectionPresenter;
     }
+
+    public short getSharingId() {
+        return sharingId;
+    }
+
+    public void setSharingId(short sharingId) {
+        this.sharingId = sharingId;
+    }
+
 }
\ No newline at end of file