/*	Ticker Ver 1.51 by Toh Lik Khoong
	Vertical Scroller developed using MSDK 4.0
	Last revised 01/03/2001
	Please contact me at lktoh@navsurf.com for any comments or suggestions
	The source code is strictly for educational purposes and cannot be modified
	or used without the express permission of the author
	Visit http://navsurf.com for the latest version and other useful applets
*/

/*	sample applet for ticker
<applet code=ticker.class width=120 height=140>
<param name=filename value="news.txt">
<param name=font value="Arial, 0, 10">
<param name=fontcolor value="FFFFFF, FFFF00">
<param name=target value="_blank">
<param name=xmargin value="20">
<param name=ymargin value="20">
<param name=spacing value="10">
<param name=bgcolor value="1002CA">
<param name=rectcolor value="000000">
<param name=speed value="40">
</applet>
*/

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import java.net.*;
import java.io.*;
import java.awt.image.ImageObserver;

public class ticker extends Applet implements Runnable{

	// global parameters
	private Thread m_thread;
	private Image m_imgBuffer = null;
	private int y_pos = 0;		// scroller
	private int cur_news = 0;	// current news item
	private int cur_pos = 0;	// mouse cursor position
	private boolean pause = false;	// pause
	private boolean m_over = false;	// mouse over
	private Vector news = new Vector();	// contains the text to display
	private Vector urls = new Vector();	// contains the corresponding URL

	// default parameters
	private int size = 10;
	private Font ft = new Font("TimesRoman",Font.PLAIN,size);
	private FontMetrics fm;
	private String filename = "news.txt";
	private String target = "_blank";
	private int height;
	private int xmargin = 10;
	private int ymargin = 0;
	private Color[] fontcolor = new Color[2];
	private Color bgcolor = new Color(0);
	private Color rectcolor;
	private int speed = 100;
	private int spacing = 20;
	private Image bgimage = null;

	public void init(){

		// retrieval of applet parameters
		String param;
		param = getParameter("size");
		if (param != null) size = Integer.parseInt(param);
		param = getParameter("font");
		if (param != null) ft = parseFont(param, ", ");
		param = getParameter("target");
		if (param != null) target = param;
		param = getParameter("xmargin");
		if (param != null) xmargin = Integer.parseInt(param);
		param = getParameter("ymargin");
		if (param != null) ymargin = Integer.parseInt(param);
		param = getParameter("bgcolor");
		if (param != null) bgcolor = new Color(Integer.parseInt(param,16));
		param = getParameter("rectcolor");
		if (param != null) rectcolor = new Color(Integer.parseInt(param,16));
		else rectcolor = bgcolor;
		param = getParameter("fontcolor");
		if (param != null) parseColor(param, ", ", fontcolor);
		param = getParameter("spacing");
		if (param != null) spacing = Integer.parseInt(param);
		param = getParameter("filename");
		if (param != null) filename = param;
		param = getParameter("speed");
		if (param != null) speed = Integer.parseInt(param);
		param = getParameter("bgimage");
		if (param != null){
			bgimage = getImage(getDocumentBase(), param);
			// performs aynchronuous image loading correctly
			prepareImage(bgimage, this);
		}
		setFont(ft);
		fm = getFontMetrics(ft);
		height = fm.getAscent() + fm.getDescent();

		// read the news file
		readFile();
	}

	private Font parseFont(String text, String delimiter){
		String font_name = "Arial";
		int font_size = 12;
		int font_style = Font.PLAIN;
		StringTokenizer st = new StringTokenizer(text, delimiter);
		if (st.hasMoreTokens()){
			font_name = st.nextToken();
			if (st.hasMoreTokens()){
				font_style = Integer.parseInt(st.nextToken());
				if (st.hasMoreTokens()){
					font_size = Integer.parseInt(st.nextToken());
				}
			}
		}
		return (new Font(font_name, font_style, font_size));
	}

	private void parseColor(String text, String delimiter, Color[] color){
		color[0] = new Color(0);
		color[1] = new Color(255, 0, 0);
		StringTokenizer st = new StringTokenizer(text, delimiter);
		if (st.hasMoreTokens()){
			color[0] = new Color(Integer.parseInt(st.nextToken(), 16));
			if (st.hasMoreTokens())
				color[1] = new Color(Integer.parseInt(st.nextToken(), 16));
		}
	}

	public boolean mouseEnter(Event e, int x, int y){
		stop();
		m_over = true;
		cur_pos = e.y;
		repaint();
		return true;
	}

	public boolean mouseExit(Event e, int x, int y){
		start();
		m_over = false;
		repaint();
		return true;
	}

	public boolean mouseMove(Event e, int x, int y){
		cur_pos = e.y;
		m_over = true;
		repaint();
		return true;
	}

	public boolean mouseDown(Event e, int x, int y){
		if (urls.elementAt(cur_news) instanceof URL){
			URL myURL = (URL) urls.elementAt(cur_news);
			getAppletContext().showDocument(myURL,getParameter("target"));
		}
		return true;
	}

	// function to read file
	private void readFile()
	{
		String line;
		try{
			URL url = new URL(getDocumentBase(), filename);
			try{	// read file
				BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
				do{
					line = in.readLine();
					if (line != null){
						try{
							StringTokenizer st = new StringTokenizer(line, "|");
							news.addElement(st.nextToken());	// get display text
							if (st.hasMoreTokens()){	// get url
								urls.addElement(new URL(getDocumentBase(), st.nextToken()));
							}
							else{	// no url, adding indicator
								urls.addElement("nourl");
							}
						}catch (NoSuchElementException nsee){}	// exception if carriage return at eof

					}
				}while (line != null);
			}
			catch (IOException e){
				news.addElement("Could not open news feed file.");
				urls.addElement("nourl");
				System.err.println("Could not open news feed file.");
			}
		}catch (MalformedURLException e){}
	}

	public void paint(Graphics g){
		if (m_imgBuffer == null){	// double buffering
			m_imgBuffer = createImage(size().width, size().height);
			render(g);	// display the ticker
		}
		g.drawImage(m_imgBuffer, 0, 0, null);
	}

	public void update(Graphics g){
		render(g);
		paint(g);
	}

	// function that displays the ticker
	public void render(Graphics g)
	{
		// drawing of the background
		g = m_imgBuffer.getGraphics();
		g.setColor(rectcolor);
		g.fillRect(0, 0, size().width, size().height);
		g.setColor(bgcolor);
		g.fillRect(xmargin, ymargin, size().width - 2 * xmargin, size().height - 2 * ymargin);
		if (bgimage != null){
			g.drawImage(bgimage, 0, 0, this);
		}
		g.setColor(fontcolor[0]);
		// set clip area for the scrolling text
		g.setClip(xmargin, ymargin, size().width - 2 * xmargin, size().height - 2 * ymargin);

		boolean reset = false;	// if true, reset the value of y_pos
		int y = 0;
		String s = "";

		while (y + y_pos < size().height){
			// calculate the position of the news item
			for (int i = 0; i < news.size(); i++){
				if (m_over){	// mouse over the text
					int b1 = y_pos + ymargin;	// top current news border
					int b2 = y_pos + ymargin;	// bottom current news border

					// search for the current news to highlight
					while (b2 < size().height){
						for (int j = 0; j < news.size(); j++){
							b1 = b2;	// set top border
							StringTokenizer st = new StringTokenizer((String) news.elementAt(j)," ",false);
							String t = "";
							while (st.hasMoreTokens()){
								s = "";
								do{
									if (!t.equals("")) s += t + " ";
									t = st.nextToken();
								}while (fm.stringWidth(s + t) < size().width - 2 * xmargin - 5 && st.hasMoreTokens());

								if (!st.hasMoreTokens() && fm.stringWidth(s + t) > size().width - 2 * xmargin - 5){
									b2 += 2 * height;
								}
								else{
									b2 += height;
								}
							}
							if (cur_pos > b1 && cur_pos < b2){	// look for current news
								cur_news = j;
							}
							b2 += spacing;	// calculate bottom border
						}
					}
					// highlight item
					if (i == cur_news && (urls.elementAt(i) instanceof URL)) g.setColor(fontcolor[1]);
					else g.setColor(fontcolor[0]);
				}

				// pause the ticker when new item appears
				if (y_pos + y == 0){
					pause = true;
				}

				// display the text
				String t = "";
				StringTokenizer st = new StringTokenizer((String) news.elementAt(i)," ",false);
				while (st.hasMoreTokens()){
					s = "";
					do{
						if (!t.equals("")) s += t + " ";
						t = st.nextToken();
					}while (fm.stringWidth(s + t) < size().width - 2 * xmargin - 5 && st.hasMoreTokens());

					y += height;

					if (st.hasMoreTokens()){
						if (y + y_pos > 0 && y + y_pos < size().height)
							g.drawString(s, xmargin + 2, y + y_pos + ymargin);
					}
					else{	// special treatment for last line (no more tokens left)
						if (fm.stringWidth(s + t) > size().width - 2 * xmargin - 5){
							// not enough space, draw on different lines
							if (y + y_pos > 0 && y + y_pos < size().height)
								g.drawString(s, xmargin + 2, y + y_pos + ymargin);
							y += height;
							if (y + y_pos > 0 && y + y_pos < size().height)
								g.drawString(t, xmargin + 2, y + y_pos + ymargin);
						}
						else{	// if not, draw on same line
							if (y + y_pos > 0 && y + y_pos < size().height)
								g.drawString(s + t, xmargin + 2, y + y_pos + ymargin);
						}
					}
				}
				y += spacing;
			}
			if (y + y_pos < 0) reset = true;
		}
		if (reset) y_pos = 0;	// reset the scroller position
	}

	// performs aynchronuous image loading correctly
	public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height){
		if ((infoflags & ImageObserver.ALLBITS) != 0){
			repaint();
			return false;
		}
		return true;
	}

	public void start(){
		m_thread = new Thread(this);
		m_thread.start();
	}

	public void stop(){
		if (m_thread != null){
			m_thread.stop();
	    	m_thread = null;
		}
		//m_thread = null;
	}

	public void run(){
		try{
			while(true){
				if (pause){	// pause when new item appears
					m_thread.sleep(4000);
					pause = false;
				}
				m_thread.sleep(speed);
				if (!m_over) y_pos--;	// scroll the ticker
				repaint();
			}
		}
		catch (InterruptedException e){}
	}
}