content: /**
   * 	Copyright (c) 2010 Philipp Giese
   * 
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * "Software"), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   * 
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   * 
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
   * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
   * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  package com.orm.androrm.statement;
  
  import java.util.HashSet;
  import java.util.Set;
  
  /**
   * This is the abstract superclass of all composed statements. 
   * Composed statement have a left and a right side that is also
   * a statement. Both sides are separated by a certain keyword.
   * <br /><br />
   * Examples are {@link AndStatement} and {@link OrStatement}. 
   * 
   * @author Philipp Giese
   */
  public abstract class ComposedStatement extends Statement {
  
  	/**
  	 * Left side of the {@link Statement}.
  	 */
  	protected Statement mLeft;
  	/**
  	 * Right side of the {@link Statement}.
  	 */
  	protected Statement mRight;
  	/**
  	 * String that separates the left side of this statement
  	 * from the right side.
  	 */
  	protected String mSeparator;
  	
  	public ComposedStatement(Statement left, Statement right) {
  		mLeft = left;
  		mRight = right;
  	}
  	
  	@Override
  	public Set<String> getKeys() {
  		Set<String> keys = new HashSet<String>();
  		
  		keys.addAll(mLeft.getKeys());
  		keys.addAll(mRight.getKeys());
  		
  		return keys;
  	}
  	
  	@Override
  	public String toString() {
  		if(mRight != null) {
  			return mLeft.toString() + mSeparator + mRight.toString();
  		}
  		
  		if(mLeft != null) {
  			return mLeft.toString();
  		}
  		
  		return super.toString();
  	}
  }
  