Watchable.java

/*
 * $Id: Watchable.java,v 1.3 2009-01-16 16:26:15 tomoke Exp $
 *
 * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle,
 * Santa Clara, California 95054, U.S.A. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
package com.sun.pdfview;

/**
 * An interface for rendering or parsing, which can be stopped and started.
 */
public interface Watchable {

    /** the possible statuses */
    public static final int UNKNOWN = 0;
    public static final int NOT_STARTED = 1;
    public static final int PAUSED = 2;
    public static final int NEEDS_DATA = 3;
    public static final int RUNNING = 4;
    public static final int STOPPED = 5;
    public static final int COMPLETED = 6;
    public static final int ERROR = 7;

    /**
     * Get the status of this watchable
     *
     * @return one of the well-known statuses
     */
    public int getStatus();

    /**
     * Stop this watchable.  Stop will cause all processing to cease,
     * and the watchable to be destroyed.
     */
    public void stop();

    /**
     * Start this watchable and run until it is finished or stopped.
     * Note the watchable may be stopped if go() with a
     * different time is called during execution.
     */
    public void go();

    /**
     * Start this watchable and run for the given number of steps or until
     * finished or stopped.
     *
     * @param steps the number of steps to run for
     */
    public void go(int steps);

    /**
     * Start this watchable and run for the given amount of time, or until
     * finished or stopped.
     *
     * @param millis the number of milliseconds to run for
     */
    public void go(long millis);
}