/*******************************************************************************
 * Copyright (c) 2000, 2005 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module dwtx.jface.dialogs.IPageChangeProvider;

import dwtx.jface.dialogs.IPageChangedListener;

import dwt.dwthelper.utils;

/**
 * Minimal interface to a page change provider. Used for dialogs which can
 * switch between multiple pages.
 *
 * @since 3.1
 */
public interface IPageChangeProvider {
    /**
     * Returns the currently selected page in the dialog.
     *
     * @return the selected page in the dialog or <code>null</code> if none is
     *         selected. The type may be domain specific. In
     *         the JFace provided dialogs this will be an instance of
     *         <code>IDialogPage</code>.
     */
    Object getSelectedPage();

    /**
     * Adds a listener for page changes in this page change provider. Has no
     * effect if an identical listener is already registered.
     *
     * @param listener
     *            a page changed listener
     */
    void addPageChangedListener(IPageChangedListener listener);

    /**
     * Removes the given page change listener from this page change provider.
     * Has no effect if an identical listener is not registered.
     *
     * @param listener
     *            a page changed listener
     */
    void removePageChangedListener(IPageChangedListener listener);

}