/*
 * Copyright (c) 2003-onwards Shaven Puppy Ltd
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'Shaven Puppy' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.puppygames.applet.widgets;

/**
 * An asyncronous operation is like a Runnable except it can throw an
 * Exception.
 * @author Cas
 */
public interface AsynchronousOperation {

	/**
	 * Do the asynchronous operation.
	 * @throws Exception
	 */
	public void run() throws Exception;

	/**
	 * Attempt to cancel the operation.
	 * @return true if the operation was successfully cancelled
	 */
	public boolean cancel();

	/**
	 * Poll the progress of the async op.
	 * @return the progress
	 */
	public int getProgress();

	/**
	 * Get the duration of the async op.
	 * @return the duration, or 0, if unknown
	 */
	public int getDuration();

	/**
	 * Get the error message if any. Call this if run() throws
	 * an Exception to get the human-readable error explanation.
	 * @return a String, or null
	 */
	public String getErrorMessage();

	/**
	 * Called when the operation is completed, in the main thread,
	 * whether successful or not
	 */
	public void onCompleted();

	/**
	 * Get the title to display for this operation, eg. "Please Wait"
	 * @return a String
	 */
	public String getTitle();

	/**
	 * Get the message to display for this operation, eg. "Loading Some Stuff"
	 * @return a String
	 */
	public String getMessage();

}