/*******************************************************************************
 * Copyright (c) 2007- VTT Technical Research Centre of Finland.
 * 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:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.g2d.element.handler;

import java.util.Collection;

import org.simantics.g2d.element.IElement;
import org.simantics.utils.datastructures.valueinterface.ValueAccess;

/**
 * Handlers public element properties
 * 
 * @See {@link PropertyHandlerImpl} default implementation
 * @author Toni Kalajainen
 */
public interface PropertyHandler extends ElementHandler {

	/**
	 * Enumerates property keys
	 * @param collection adds property keys
	 */
	void enumerateProperties(Collection<String> collection);
	
	/**
	 * Attach/deattach (=null) value access to this property handler.
	 * Though each propertyhandler can be attached only one value access,
	 * there can be parallel property handlers. 
	 *   
	 * @param e
	 * @param access value access or null (to deattach)
	 */
	void setValueSource(IElement e, ValueAccess<String> access);
	
	Object getValue(IElement e, String key);
	
}