AddImplementedInterfaceVisitor.java

/*
 *  Author:  Chris Seguin
 *
 *  This software has been developed under the copyleft
 *  rules of the GNU General Public License.  Please
 *  consult the GNU General Public License for more
 *  details about use and distribution of this software.
 */
package org.acm.seguin.refactor.type;

import org.acm.seguin.parser.ChildrenVisitor;
import org.acm.seguin.parser.ast.ASTName;
import org.acm.seguin.parser.ast.ASTNameList;
import org.acm.seguin.parser.ast.ASTUnmodifiedClassDeclaration;

/**
 *  Walks the parse tree and updates it
 *
 *@author     Grant Watson
 *@created    December 1, 2000
 */
public class AddImplementedInterfaceVisitor extends ChildrenVisitor {

	/**
	 *  Constructor for the AddImplementedInterfaceVisitor object
	 */
	public AddImplementedInterfaceVisitor() { }


	/**
	 *  The ASTNameList of an ASTUnmodifiedClassDeclaration holds the names of
	 *  interfaces implemented by the class. This method adds an interface name
	 *  specified by the data parameter to the ASTNameList . If no ASTNameList is
	 *  present, then one is created.
	 *
	 *@param  node  Description of Parameter
	 *@param  data  Description of Parameter
	 *@return       Description of the Returned Value
	 */
	public Object visit(ASTUnmodifiedClassDeclaration node, Object data)
	{
		ASTName interfaceName = (ASTName) data;
		ASTNameList nameList = null;
		// Find the ASTNameList or add one
		for (int i = 0; i < node.jjtGetNumChildren(); i++) {
			if (node.jjtGetChild(i) instanceof ASTNameList) {
				nameList = (ASTNameList) node.jjtGetChild(i);
			}
		}
		if (nameList == null) {
			nameList = new ASTNameList(0);
			node.jjtInsertChild(nameList, node.jjtGetNumChildren() - 1);
		}
		// Determine whether the interface name is already in the list of implemented interfaces
		boolean exists = false;
		for (int i = 0; i < nameList.jjtGetNumChildren(); i++) {
			ASTName astName = (ASTName) nameList.jjtGetChild(i);
			if (astName.equals(interfaceName)) {
				exists = true;
				break;
			}
		}
		// If the interface is not there, then add it.
		if (!exists) {
			nameList.jjtAddChild(interfaceName, nameList.jjtGetNumChildren());
		}
		return null;
	}

}