/*******************************************************************************
 * 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;

/**
 * Interface for listening to perspective lifecycle events.
 * <p>
 * This interface may be implemented by clients.
 * </p>
 *
 * @see IPageService#addPerspectiveListener(IPerspectiveListener)
 * @see PerspectiveAdapter
 */
public interface IPerspectiveListener {
    /**
     * Notifies this listener that a perspective in the given page
     * has been activated.
     *
     * @param page the page containing the activated perspective
     * @param perspective the perspective descriptor that was activated
     * @see IWorkbenchPage#setPerspective
     */
    public void perspectiveActivated(IWorkbenchPage page,
            IPerspectiveDescriptor perspective);

    /**
     * Notifies this listener that a perspective has changed in some way 
     * (for example, editor area hidden, perspective reset,
     * view show/hide, editor open/close, etc).
     *
     * @param page the page containing the affected perspective
     * @param perspective the perspective descriptor
     * @param changeId one of the <code>CHANGE_*</code> constants on IWorkbenchPage
     */
    public void perspectiveChanged(IWorkbenchPage page,
            IPerspectiveDescriptor perspective, String changeId);
}
