Copyright (c) 2009, 2011 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
/*******************************************************************************
 * Copyright (c) 2009, 2011 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
 ******************************************************************************/
package org.eclipse.equinox.log;

import java.security.Permission;
import java.security.PermissionCollection;
import java.util.Enumeration;
import java.util.NoSuchElementException;

Stores a set of LogPermission permissions.
See Also:
Permission
Permissions
PermissionCollection
@ThreadSafe
Since:
3.7/**
 * Stores a set of <code>LogPermission</code> permissions.
 *
 * @ThreadSafe
 * @see java.security.Permission
 * @see java.security.Permissions
 * @see java.security.PermissionCollection
 * @since 3.7
 */
public final class LogPermissionCollection extends PermissionCollection {
	private static final long serialVersionUID = -1955409691185916778L;
	LogPermission logPermission;

	@Override
	public void add(Permission permission) {
		if (!(permission instanceof LogPermission))
			throw new IllegalArgumentException("invalid permission: " + permission); //$NON-NLS-1$
		if (isReadOnly())
			throw new SecurityException("attempt to add a LogPermission to a readonly LogPermissionCollection"); //$NON-NLS-1$
		if (permission != null)
			logPermission = (LogPermission) permission;
	}

	@Override
	public Enumeration<Permission> elements() {
		return new Enumeration<Permission>() {
			private boolean hasMore = (logPermission != null);

		@Override
			public boolean hasMoreElements() {
				return hasMore;
			}

		@Override
			public Permission nextElement() {
				if (hasMore) {
					hasMore = false;
					return logPermission;
				}
				throw new NoSuchElementException();
			}
		};
	}

	@Override
	public boolean implies(Permission permission) {
		return logPermission != null && logPermission.implies(permission);
	}

}