/*******************************************************************************
 * Copyright (c) 2005, 2006 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal.dialogs;

import java.util.Collection;
import java.util.HashSet;

import org.eclipse.jface.preference.IPreferenceNode;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerFilter;

/**
 * The PreferenceNodeFilter is a filter that only matches
 * a set of ids.
 */
public class PreferenceNodeFilter extends ViewerFilter {

	Collection ids = new HashSet();

	/**
	 * Create a new instance of the receiver on a
	 * list of filteredIds.
	 * @param filteredIds The collection of ids that
	 * will be shown.
	 */
	public PreferenceNodeFilter(String[] filteredIds) {
		super();
		for (int i = 0; i < filteredIds.length; i++) {
			ids.add(filteredIds[i]);
		}
	}

	/* (non-Javadoc)
	 * @see org.eclipse.jface.viewers.ViewerFilter#select(org.eclipse.jface.viewers.Viewer, java.lang.Object, java.lang.Object)
	 */
	public boolean select(Viewer viewer, Object parentElement, Object element) {
		return checkNodeAndChildren((IPreferenceNode) element);
	}

	/**
	 * Check to see if the node or any of its children 
	 * have an id in the ids.
	 * @param node WorkbenchPreferenceNode
	 * @return boolean <code>true</code> if node or oe of its children
	 * has an id in the ids.
	 */
	private boolean checkNodeAndChildren(IPreferenceNode node) {
		if(ids.contains(node.getId())) {
			return true;
		}
		
		IPreferenceNode[] subNodes = node.getSubNodes();
		for (int i = 0; i < subNodes.length; i++) {
			if(checkNodeAndChildren(subNodes[i])) {
				return true;
			}
			
		}
		return false;
	}

}