QueueState.java

package ca.ubc.cs.spl.aspectPatterns.examples.state.java;

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/**
 * Defines the interface for <i>State</i>s within this queue example. The 
 * operations provided are <code>insert(..)</code>, <code>getFirst(..)</code>,
 * and <code>removeFirst(..)</code>.  
 *
 * @author  Jan Hannemann
 * @author  Gregor Kiczales
 * @version 1.1, 02/17/04
 */

public interface QueueState { 
    
    /**
     * Tries to insert an object into the queue. Returns true if successful, 
     * false otherwiese.
     *
     * @param context the <i>Context</i> for this design pattern (for update 
     * on demand)
     * @param arg the object to be inserted into the queue
     * @return true if insertion was successful, false otherwise.
     */ 
	
	public boolean insert(QueueContext context, Object arg);

    /**
     * Returns the first item in the queue
     *
     * @param context the <i>Context</i> for this design pattern (for update 
     * on demand)
     * @return the first item in the queue
     */ 

	public Object  getFirst(QueueContext context);	

    /**
     * Tries to remove an object from the queue. Returns true if successful,
     * false otherwiese.
     *
     * @param context the <i>Context</i> for this design pattern (for update 
     * on demand)
     * @return true if deletion was successful, false otherwise.
     */ 

	public boolean removeFirst(QueueContext context);	 

}