algthread.java

java算法大全

/* AlgThread.java */

import java.awt.*;
import java.io.*;
import java.applet.*;
import java.net.*;
import java.util.*;

/**
 * <code>AlgThread</code> is an extension of the provided Java 
 * multi-threading package.
 * It enables the graphical display of the main execution thread to be
 * updated during the execution of the algorithm.
 * <p>
 * A section of this source file is normally displayed on the TextFrame.
 * This section starts with the line after 
 * <code>/*------------------*</code><code>/
 * </code> and finishes before the line <code>//------------
 * </code>.
 * Every line starting with <code>/*-*</code><code>/</code> will be discarded in
 * the source code display area and each line is terminated by the first
 * encounter of <code>/*-*</code><code>/</code>.
 * <p>
 * The source file <code>AlgThread.java</code> is <b>to be
 * modified/completed</b> for separate animation algorithms.
 *
 * @authorWoi L Ang
 * @sinceJDK1.0
 */
public class AlgThread extends Thread {
	/**
	 * Size of the data set appropriate for algorighm animation.
	 */
	public int max_data = 7;
	/**
	 * Array of strings used to set the choices of the data choice button
	 * in data menu.
	 */
	public static String[] dataSets = 
	{"Data Set 1", "Data Set 2", "Data Set 3"};

	private static String[] URLs =
		{ "http://ciips.ee.uwa.edu.au/~koh-ta/BD/BD.form",
		 "BD/BD.form",
		 "http://ciips.ee.uwa.edu.au/~koh-ta/BD/BD1.form"
		};

	/**
	 * The initial caller of the constructor of this class.
	 * It holds the references to all existing panels.
	 */ 
	public AlgAnimFrame frame;
	/**
	 * A reference to the drawing panel in order to update the animation
	 * during the execution of the algorithm.
	 * @see DrawingPanel
	 */
	public DrawingPanel drawingPanel;

	BlockDiagram bd;
	//TransDiagram td;

	/**
	 * Creates a new thread using the frame passed in as the parameter.
	 * If this constructor is called from the frame constructor,
	 * a drawingPanel will be initialized and assigned to the frame
	 * class.
	 * 
	 * @param frame An extended frame where the algorithm is going to 
	 * execute in.
	 *
	 * @see AlgAnimFrame
	 */
	public AlgThread(AlgAnimFrame frame) {
			this.frame = frame;
			this.drawingPanel = frame.getDrawingPanel();
			if (frame != null && frame.getAlg() != null && 
					frame.getAlg().drawingPanel != null) {
					// drawingPanel already created -> this constructor called from
					// clicking the run button -> use the generated data set
			}
	}

	/**
	 * Sets the delay between each animation step. This determines
	 * the rate the drawingPanel is updated. The <code>setDelay</code>
	 * method is normally called by the action listener of
	 * the <code>delay choice button</code> on the control panel.
	 * @param delay The delay set in milliseconds.
	 */
	public void setDelay(int delay) {
		drawingPanel.setDelay(delay);
	}

	/**
	 * Generate data based on the choice made on the menu.
	 * This method is application specific
	 * and the contents for the satisfaction of each 'if' statement
	 * have to be filled in based on the algorithm.
	 */
	public void generateData() {
		URL url;
		this.drawingPanel = frame.getDrawingPanel();
		int choice = frame.getDataChoice();
		System.out.println("genData " + choice );
		switch( choice ) {
			case 0: 
				bd = new BlockDiagram("Test");
				bd.ConsTestCase();
				break;
			case 1:
			case 2:
				System.out.println("URL: " + URLs[choice] );
				URL homeURL = frame.getApplet().getCodeBase();
				try {
					url = new URL( homeURL, URLs[choice] );
					bd = new BlockDiagram( url );
				} catch( Exception e ) {
					System.out.println("Error forming URL from " + URLs[choice] );
				}
				break;
			default:
				System.out.println("Invalid choice");
			} 
		System.out.println("generateData: exit" );
		drawingPanel.init();
		}

/*--------------------------------------------------------------------*/
//----
	/**
	 * This method is invoked when the <code>Thread</code> class
	 * <code>start()</code> method is called.
	 * It contains the statements to execute the methods which perform
	 * the algorithm. This method is to be completed based on separate
	 * animation algorithms.
	 * @see java.lang.Thread
	 */
	public void run() {
		generateData();
		frame.getTextFrame();
		// alg here
		drawingPanel.addDrawingObj( bd );

		// finish sorting
		frame.finishAlg();
		}

	/**
	 * Restore the drawing panel at the beginning or the end of each
	 * simulation.
	 */
	public void restoreDrawingPanel() {
		}

	/**
	 * This method is to be placed after the line where the fast
	 * forward function is to be performed.
	 */
	public void waitSkip() {
		if (!drawingPanel.getSkip()) return;
		((ImageButton)frame.getSkipItem()).setEnable();
		((ImageButton)frame.getRunItem()).setEnable();
		((ImageButton)frame.getStopItem()).setDisable();
		drawingPanel.setSkip(false);
		frame.setStep(true);
		frame.waitStep();
		}
}