/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.ui.internal;

import org.eclipse.core.commands.common.EventManager;
import org.eclipse.core.runtime.SafeRunner;
import org.eclipse.jface.util.SafeRunnable;
import org.eclipse.ui.IPageListener;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.internal.misc.UIStats;

/**
 * Part listener list.
 */
public class PageListenerList extends EventManager {

	/**
	 * PartNotifier constructor comment.
	 */
	public PageListenerList() {
		super();
	}

	/**
	 * Adds an IPartListener to the part service.
	 */
	public void addPageListener(IPageListener l) {
		addListenerObject(l);
	}

	/**
	 * Calls a page listener with associated performance event instrumentation
	 *
	 * @param runnable
	 * @param listener
	 * @param page
	 * @param description
	 */
	private void fireEvent(SafeRunnable runnable, IPageListener listener, IWorkbenchPage page, String description) {
		String label = null;// for debugging
		if (UIStats.isDebugging(UIStats.NOTIFY_PAGE_LISTENERS)) {
			label = description + page.getLabel();
			UIStats.start(UIStats.NOTIFY_PAGE_LISTENERS, label);
		}
		SafeRunner.run(runnable);
		if (UIStats.isDebugging(UIStats.NOTIFY_PAGE_LISTENERS)) {
			UIStats.end(UIStats.NOTIFY_PAGE_LISTENERS, listener, label);
		}
	}

	/**
	 * Notifies the listener that a part has been activated.
	 */
	public void firePageActivated(final IWorkbenchPage page) {
		for (Object listener : getListeners()) {
			final IPageListener pageListener = (IPageListener) listener;
			fireEvent(new SafeRunnable() {
				@Override
				public void run() {
					pageListener.pageActivated(page);
				}
			}, pageListener, page, "activated::"); //$NON-NLS-1$
		}
	}

	/**
	 * Notifies the listener that a part has been closed
	 */
	public void firePageClosed(final IWorkbenchPage page) {
		for (Object listener : getListeners()) {
			final IPageListener pageListener = (IPageListener) listener;
			fireEvent(new SafeRunnable() {
				@Override
				public void run() {
					pageListener.pageClosed(page);
				}
			}, pageListener, page, "closed::"); //$NON-NLS-1$
		}
	}

	/**
	 * Notifies the listener that a part has been opened.
	 */
	public void firePageOpened(final IWorkbenchPage page) {
		for (Object listener : getListeners()) {
			final IPageListener pageListener = (IPageListener) listener;
			fireEvent(new SafeRunnable() {
				@Override
				public void run() {
					pageListener.pageOpened(page);
				}
			}, pageListener, page, "opened::"); //$NON-NLS-1$
		}
	}

	/**
	 * Removes an IPartListener from the part service.
	 */
	public void removePageListener(IPageListener l) {
		removeListenerObject(l);
	}
}