/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.examples.propertysheet;

import java.util.Vector;

import org.eclipse.swt.graphics.RGB;

/**
 * A Group Element
 */
public class GroupElement extends OrganizationElement {
	public static String P_USERS = "users"; //$NON-NLS-1$
	public static String P_SUBGROUPS = "subgroups"; //$NON-NLS-1$
	public static String P_CONTENTS = "contents"; //$NON-NLS-1$
	private Vector subGroups;
	private Vector users;
	// must be synchronized to contain both the references of subGroups and users
	private Vector contents;
/**
 * Constructor.
 * Creates a new GroupElement within the passed parent GroupElement,
 * gives it the passed name property, sets Icon.
 *
 * @param name the name 
 * @param parent the parent
 */
public GroupElement(String name, GroupElement parent) {
	super(name, parent);
}
/**
 * Adds an OrganizationElement to this GroupElement.
 *
 * @param userGroup The Organization Element
 */
public void add(OrganizationElement userGroup) {
	if (userGroup.isUser() || userGroup.isGroup()) {
		getContents().add(userGroup);		
	}
	if (userGroup.isGroup()) {
		getSubGroups().add(userGroup);
		// synchronizes backpointer of userGroup: defensive
		userGroup.setParent(this);
	}
	if (userGroup.isUser()) {
		getUsers().add(userGroup);
		// synchronizes backpointer of userGroup: defensive
		userGroup.setParent(this);
	}

}
/**
 * Creates a new <code>GroupElement</code>
 * nested in this <code>GroupElement<code>
 *
 * @param name the name of the sub group
 */
public GroupElement createSubGroup(String name) {
	GroupElement newGroup = new GroupElement(name, this);
	add(newGroup);
	return newGroup;
}
/**
 * Creates a new <code>UserElement</code>
 *
 * @param the name of the user element
 */
public UserElement createUser(String name) {
	UserElement newUser = new UserElement(name, this);
	add(newUser);
	return newUser;
}
/**
 * Deletes an OrganizationElement from this GroupElement.
 *
 * @param userGroup the Organization Element
 */
public void delete(OrganizationElement userGroup) {
	if (userGroup.isUser() || userGroup.isGroup()) {
		getContents().remove(userGroup);
	}
	if (userGroup.isGroup()) {
		getSubGroups().remove(userGroup);
		// synchronizes backpointer of userGroup: defensive
	}
	if (userGroup.isUser()) {
		getUsers().remove(userGroup);
		// synchronizes backpointer of userGroup: defensive
	}
}
/* (non-Javadoc)
 * Method declared on IWorkbenchAdapter
 */
public Object[] getChildren(Object o) {
	return getContents().toArray();
}
/**
 * Returns the content
 */
private Vector getContents() {
	if (contents == null)
		contents = new Vector();
	return contents;
}
/* (non-Javadoc)
 * Method declared on IPropertySource
 */
public Object getEditableValue() {
	return this.toString();
}
/**
 * Returns the error message
 */
public String getErrorMessage() {
	return null;
}
/**
 * Returns the subgroups
 */
private Vector getSubGroups() {
	if (subGroups == null)
		subGroups = new Vector();
	return subGroups;
}
/**
 * Returns the users
 */
private Vector getUsers() {
	if (users == null)
		users = new Vector();
	return users;
}
/* (non-Javadoc)
 * Method declared on OrganizationElement
 */
public boolean isGroup() {
	return true;
}
/* (non-Javadoc)
 * @see org.eclipse.ui.model.IWorkbenchAdapter#getForeground(java.lang.Object)
 */
public RGB getForeground(Object element) {
    return null;
}
/* (non-Javadoc)
 * @see org.eclipse.ui.model.IWorkbenchAdapter#getBackground(java.lang.Object)
 */
public RGB getBackground(Object element) {
    return null;
}
}