/*******************************************************************************
 * Copyright (c) 2004, 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
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/

module dwtx.jface.bindings.SchemeEvent;

import dwtx.jface.bindings.Scheme;

import dwtx.core.commands.common.AbstractNamedHandleEvent;

import dwt.dwthelper.utils;

/**
 * An instance of this class describes changes to an instance of
 * <code>IScheme</code>.
 * <p>
 * This class is not intended to be extended by clients.
 * </p>
 *
 * @since 3.1
 * @see ISchemeListener#schemeChanged(SchemeEvent)
 */
public final class SchemeEvent : AbstractNamedHandleEvent {

    /**
     * The bit used to represent whether the scheme has changed its parent.
     */
    private static const int CHANGED_PARENT_ID = LAST_USED_BIT << 1;

    /**
     * The scheme that has changed; this value is never <code>null</code>.
     */
    private const Scheme scheme;

    /**
     * Creates a new instance of this class.
     *
     * @param scheme
     *            the instance of the interface that changed; must not be
     *            <code>null</code>.
     * @param definedChanged
     *            true, iff the defined property changed.
     * @param nameChanged
     *            true, iff the name property changed.
     * @param descriptionChanged
     *            <code>true</code> if the description property changed;
     *            <code>false</code> otherwise.
     * @param parentIdChanged
     *            true, iff the parentId property changed.
     */
    public this(Scheme scheme, bool definedChanged,
            bool nameChanged, bool descriptionChanged,
            bool parentIdChanged) {
        super(definedChanged, descriptionChanged, nameChanged);

        if (scheme is null) {
            throw new NullPointerException();
        }
        this.scheme = scheme;

        if (parentIdChanged) {
            changedValues |= CHANGED_PARENT_ID;
        }
    }

    /**
     * Returns the instance of the scheme that changed.
     *
     * @return the instance of the scheme that changed. Guaranteed not to be
     *         <code>null</code>.
     */
    public final Scheme getScheme() {
        return scheme;
    }

    /**
     * Returns whether or not the parentId property changed.
     *
     * @return true, iff the parentId property changed.
     */
    public final bool isParentIdChanged() {
        return ((changedValues & CHANGED_PARENT_ID) !is 0);
    }
}