1 files changed, 190 insertions, 0 deletions
diff --git a/TAO/examples/Simulator/DOVEBrowser/Queue.java b/TAO/examples/Simulator/DOVEBrowser/Queue.java
new file mode 100644
index 00000000000..7ffaba15c52
--- /dev/null
+++ b/TAO/examples/Simulator/DOVEBrowser/Queue.java
@@ -0,0 +1,190 @@
+// $Id$
+
+
+import java.util.Enumeration;
+
+public class Queue
+{
+  // Friendly?
+  Queue_Node head_ = null;
+  Queue_Node tail_ = null;
+  
+  private int length_ = 0;
+  
+  public Queue()
+    {     
+    }
+
+  public Enumeration forward_iterator()
+    {
+      return new Queue_Iterator(this, Queue_Iterator.FORWARD);
+    }
+
+  public Enumeration reverse_iterator()
+    {
+      return new Queue_Iterator(this, Queue_Iterator.REVERSE);
+    }
+  
+  public void enqueue_tail(Object new_data)
+    {
+      Queue_Node new_node = new Queue_Node(new_data);
+
+      if (tail_ == null)
+	{
+	  tail_ = new_node;
+	  head_ = new_node;
+	}
+      else
+	{
+	  new_node.prev_ = tail_;
+	  tail_.next_ = new_node;
+	  tail_ = new_node;
+	}
+
+      length_++;
+    }
+
+  public void enqueue_head(Object new_data)
+    {
+      Queue_Node new_node = new Queue_Node(new_data);
+	    
+      if (head_ == null)
+	{
+	  tail_ = new_node;
+	  head_ = new_node;
+	}
+      else
+	{
+	  new_node.next_ = head_;
+	  head_.prev_ = new_node;
+	  head_ = new_node;
+	}
+
+      length_++;
+    }
+  
+  public Object dequeue_head()
+    {
+      Object return_value = null;
+      
+      if (head_ == null)
+	return_value = null;
+      else if (tail_ == head_)
+	{
+	  return_value = head_.data_;
+	  tail_ = null;
+	  head_ = null;
+	}
+      else
+	{
+	  return_value = head_.data_;
+	  head_ = head_.next_;
+	  head_.prev_ = null;	  
+	}
+
+      length_--;
+
+      return return_value;
+    }
+  
+  public Object dequeue_tail()
+    {
+      Object return_value = null;
+      
+      if (tail_ == null)
+	return_value = null;
+      else if (tail_ == head_)
+	{
+	  return_value = tail_.data_;
+	  tail_ = null;
+	  head_ = null;
+	}
+      else
+	{	  
+	  return_value = tail_.data_;
+	  tail_ = tail_.prev_;
+	  tail_.next_ = null;	  
+	}
+
+      length_--;
+
+      return return_value;
+    }
+
+  public int length()
+    {
+      return length_;
+    }
+
+  public Object head()
+    {
+      if (head_ != null)
+	return head_.data_;
+      else
+	return null;
+    }
+
+  public Object tail()
+    {
+      if (tail_ != null)
+	return tail_.data_;
+      else
+	return null;
+    }
+}
+
+class Queue_Node
+{
+  public Queue_Node prev_ = null;
+  public Queue_Node next_ = null;;
+  public Object data_;
+
+  public Queue_Node(Object data)
+    {
+      data_ = data;
+    }
+}
+
+class Queue_Iterator implements Enumeration
+{
+  public static final boolean FORWARD = true;
+  public static final boolean REVERSE = false;
+  
+  private Queue queue_;
+  private Queue_Node queue_ptr_;
+  private boolean direction_ = FORWARD;
+  
+  public Queue_Iterator(Queue queue)
+    {
+      queue_ = queue;
+      queue_ptr_ = queue.head_;
+    }
+
+  public Queue_Iterator(Queue queue, boolean direction)
+    {
+      queue_ = queue;
+      direction_ = direction;
+
+      if (direction_)
+	queue_ptr_ = queue_.head_;
+      else
+	queue_ptr_ = queue_.tail_;
+    }
+
+  public Object nextElement()
+    {
+      Object data = queue_ptr_.data_;
+      
+      if (direction_)
+	queue_ptr_ = queue_ptr_.next_;
+      else
+	queue_ptr_ = queue_ptr_.prev_;
+
+      return data;
+    }
+
+  public boolean hasMoreElements()
+    {
+      return queue_ptr_ != null;
+    }
+}