/*******************************************************************************
 * Copyright (c) 2000, 2004 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.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;
    }
}