SquirrelJME/SquirrelJME

// -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
// ---------------------------------------------------------------------------
// SquirrelJME
//     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
// ---------------------------------------------------------------------------
// SquirrelJME is under the Mozilla Public License Version 2.0.
// See license.mkd for licensing and copyright information.
// ---------------------------------------------------------------------------

package javax.microedition.swm;

import cc.squirreljme.runtime.cldc.annotation.Api;

/**
 * This class provides static methods for obtaining the application suite and
 * task manager.
 *
 * @since 2016/06/24
 */
@Api
public class ManagerFactory
{
    /** Lock for initialization. */
    private static final Object _LOCK =
        new Object();
    
    /** The suite manager. */
    private static volatile SuiteManager _SUITE_MANAGER;
    
    /** The task manager. */
    private static volatile TaskManager _TASK_MANAGER;
    
    /**
     * Returns an instance of the suite manager that the application may use
     * to manage suites on the system.
     *
     * @return The manager which is used to manage suites installed on the
     * system.
     * @throws SecurityException If the {@code {@link SWMPermission}("client",
     * "manageSuite")} or {@code {@link SWMPermission}("crossClient",
     * "manageSuite")} permission is not permitted.
     * @since 2016/06/24
     */
    @Api
    public static SuiteManager getSuiteManager()
        throws SecurityException
    {
        // Lazily initialize
        synchronized (ManagerFactory._LOCK)
        {
            SuiteManager rv = ManagerFactory._SUITE_MANAGER;
            if (rv == null)
                ManagerFactory._SUITE_MANAGER =
                    (rv = new __SystemSuiteManager__());
            return rv;
        }
    }
    
    /**
     * This returns an instance of the task manager which is used to start,
     * stop, and enumerate currently running tasks.
     *
     * @return The manager which is used to manage tasks which are currently
     * running.
     * @throws SecurityException If the {@code {@link SWMPermission}("client",
     * "manageTask")} or {@code {@link SWMPermission}("crossClient",
     * "manageTask")} permission is not permitted.
     * @since 2016/06/24
     */
    @Api
    public static TaskManager getTaskManager()
        throws SecurityException
    {
        // Lazily initialize so that the class is easier to bring up rather
        // than at class initialization time
        synchronized (ManagerFactory._LOCK)
        {
            TaskManager rv = ManagerFactory._TASK_MANAGER;
            if (rv == null)
                ManagerFactory._TASK_MANAGER =
                    (rv = new __SystemTaskManager__());
            return rv;
        }
    }
}