text: /*******************************************************************************
   * Copyright (c) 2004 Actuate Corporation.
   * All rights reserved. This program and the accompanying materials
   * are made available under the terms of the Eclipse Public License v1.0
   * which accompanies this distribution, and is available at
   * http://www.eclipse.org/legal/epl-v10.html
   *
   * Contributors:
   *  Actuate Corporation  - initial API and implementation
   *******************************************************************************/
  
  package org.eclipse.birt.report.model.elements;
  
  import org.eclipse.birt.report.model.api.DesignElementHandle;
  import org.eclipse.birt.report.model.api.ParameterGroupHandle;
  import org.eclipse.birt.report.model.api.elements.ReportDesignConstants;
  import org.eclipse.birt.report.model.core.ContainerSlot;
  import org.eclipse.birt.report.model.core.DesignElement;
  import org.eclipse.birt.report.model.core.Module;
  import org.eclipse.birt.report.model.elements.interfaces.IParameterGroupModel;
  
  /**
   * This class represents a parameter group. A parameter group creates a visual
   * grouping of parameters. The developer controls the order that groups appear
   * in the UI, and the order in which parameters appear in the group. The
   * BIRT-provided runtime UI will may choose to allow the user to expand &
   * collapse parameter groups independently.
   * 
   */
  
  public class ParameterGroup extends DesignElement
  		implements
  			IParameterGroupModel
  {
  
  	/**
  	 * Default constructor.
  	 */
  
  	public ParameterGroup( )
  	{
  		initSlots( );
  	}
  
  	/**
  	 * Constructs the parameter group with an optional name.
  	 * 
  	 * @param theName
  	 *            the optional name
  	 */
  
  	public ParameterGroup( String theName )
  	{
  		super( theName );
  		initSlots( );
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.eclipse.birt.report.model.core.DesignElement#getSlot(int)
  	 */
  
  	public ContainerSlot getSlot( int slot )
  	{
  		assert slot == PARAMETERS_SLOT;
  		return slots[PARAMETERS_SLOT];
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.eclipse.birt.report.model.core.DesignElement#apply(org.eclipse.birt.report.model.elements.ElementVisitor)
  	 */
  
  	public void apply( ElementVisitor visitor )
  	{
  		visitor.visitParameterGroup( this );
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.eclipse.birt.report.model.core.DesignElement#getElementName()
  	 */
  
  	public String getElementName( )
  	{
  		return ReportDesignConstants.PARAMETER_GROUP_ELEMENT;
  	}
  
  	/*
  	 * (non-Javadoc)
  	 * 
  	 * @see org.eclipse.birt.report.model.core.DesignElement#getHandle(org.eclipse.birt.report.model.elements.ReportDesign)
  	 */
  
  	public DesignElementHandle getHandle( Module module )
  	{
  		return handle( module );
  	}
  
  	/**
  	 * Returns an API handle for this element.
  	 * 
  	 * @param module
  	 *            the report design
  	 * @return an API handle for this element
  	 */
  
  	public ParameterGroupHandle handle( Module module )
  	{
  		if ( handle == null )
  		{
  			handle = new ParameterGroupHandle( module, this );
  		}
  		return (ParameterGroupHandle) handle;
  	}
  
  }