/*
 * Banner.java
 *      A simple Java Banner set
 *      Usage:  <applet code="Banner.class width=100 height=30>
 *		# Required parameters:
 *		<param name="font" value="a_font_file.pcf">	#font
 *		<param name="text" value="the message">		#message
 *		# Optional parameters:
 *		<param name="fg" value="#ffccee">	#fg color
 *		<param name="bg" value="green">		#bg color
 *		<param name="margin" value="3">	#top margin
 *		<param name="delay" value="50">	#delay in ms between moves
 *		<param name="step" value="3">	#size of move
 *              </applet>
 *
 * Ken Shirriff         ken.shirriff@eng.sun.com
 *
 * Copyright (c) 1997 Sun Microsystems, Inc. All Rights Reserved.
 *
 * SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 * Please refer to the file "license.txt"
 * for further important copyright and licensing information.
 */

import java.awt.*;
import java.awt.image.*;
import java.applet.Applet;
import java.net.*;
import java.io.*;
import pcffont.*;

public class Banner extends Applet implements Runnable {
	PCFFont font;
	Thread thread;
	int dispWidth, dispHeight;
	Image scrollImg = null;
	Image backImg = null;
	Color bg = Color.white;
	int topMargin;
	int delay = 50;
	int step = 5;
	String back = null;
	boolean okay = false;

	public void init() {

		// Read the parameters
		String fontname = getParameter("font");
		String text = getParameter("text");
		String fgColor = getParameter("fg");
		String bgColor = getParameter("bg");
		String margin = getParameter("margin");
		String delayString = getParameter("delay");
		String stepString = getParameter("step");
		String offset = getParameter("offset");
		back = getParameter("backwards");
		if (fontname == null || text == null) {
			err("Must specify text and font");
			return;
		}

		// Convert the text to unicode (i.e. handle \u1234)
		text = PCFFont.toUnicode(text);

		// Apply offset if any
		if (offset != null) {
			int off = Integer.parseInt(offset);
			StringBuffer sb = new StringBuffer(text);
			for (int i = 0; i < text.length(); i++) {
				int ch = (int)sb.charAt(i);
				if (ch+off < 256) {
					sb.setCharAt(i, (char)(ch+off));
				}
			}
			text = new String(sb);
		}
		if (back != null) {
			StringBuffer sb = new StringBuffer(text);
			StringBuffer sb2 = new StringBuffer(text);
			for (int i = 0; i < sb.length(); i++) {
				sb2.setCharAt(i,
					sb.charAt(sb.length()-i-1));
			}
			text = new String(sb2);
		}

		// Load the font
		showStatus("Loading font...");
		try {
			URL url = new URL(getDocumentBase(), fontname);
			font = new PCFFont(url.openStream());
		} catch (Exception e) {
			err("Couldn't open the font "+fontname);
			return;
		}
		showStatus("");

		// Compute the size of the display and create the image buffer
		dispWidth = size().width;
		dispHeight = size().height;
		if (margin != null) {
			topMargin = Integer.parseInt(margin);
		} else {
			topMargin = (dispHeight-font.getHeight())/2;
			if (topMargin<0) {
				topMargin = 0;
			}
		}
		backImg = createImage(dispWidth, dispHeight);

		// Set the colors
		font.setBgColor(null);
		if (bgColor != null) {
			try {
				bg = parseColor(bgColor);
			} catch (Exception e) {}
		}
		if (fgColor != null) {
			try {
				font.setFgColor(parseColor(fgColor));
			} catch (Exception e) {
				System.out.println("Exception "+e);
			}
		}

		// Render the text into the image
		scrollImg = font.stringImage(text);

		// Set the scrolling parameters
		if (delayString != null) {
			delay = Integer.parseInt(delayString);
		}
		if (stepString != null) {
			step = Integer.parseInt(stepString);
		}

		okay = true;
		start();
	}

	String err_str = null;

	// Display errors in the window to aid debugging
	public void paint(Graphics g) {
		if (err_str != null) {
			g.setColor(Color.blue);
			g.fillRect(0,0,500,500);
			g.setColor(Color.black);
			g.drawString(err_str, 10, 20);
		}
	}

	void err(String s) {
		err_str = s;
		repaint();
		showStatus(s);
		System.out.println("Error: "+s);
	}

	String colornames[] = { "black", "blue", "cyan", "darkGray", "gray",
		"green", "lightGray", "magenta", "orange", "pink", "red",
		"white", "yellow", "clear"};

	Color colors[] = {Color.black, Color.blue, Color.cyan, Color.darkGray,
		Color.gray, Color.green, Color.lightGray, Color.magenta,
		Color.orange, Color.pink, Color.red, Color.white,
		Color.yellow, null};


	// Convert a color name or #aabbcc color into a Java Color
	Color parseColor(String s) throws Exception {
		if (s.length()==7 && s.charAt(0)=='#') {
			return new Color(
			    Integer.parseInt(s.substring(1,3),16), // r
			    Integer.parseInt(s.substring(3,5),16), // g
			    Integer.parseInt(s.substring(5,7),16)); // b
		} else {
			for (int i=0; i<colors.length; i++) {
				if (s.equalsIgnoreCase(colornames[i])) {
					return colors[i];
				}
			}
		}
		throw new Exception("Couldn't identify color "+s);
	}

	// Start the movement thread
	public void start() {
		if (!okay) {
			return;
		}
		if (thread == null) {
			thread = new Thread(this);
			thread.start();
		}
	}

	// Stop the movement thread
	public void stop() {
		if (thread != null) {
			thread.stop();
		}
		thread = null;
	}

	// Move the image across the screen
	public void run() {
		int xpos = 0;
		if (!okay) {
			return;
		}

		while (thread == Thread.currentThread()) {
			try {
				thread.sleep(delay);
			} catch (InterruptedException e) {}
			xpos += step;
			if (xpos > scrollImg.getWidth(null) + dispWidth) {
				xpos = 0;
			}
			if (xpos < 0) {
				xpos = scrollImg.getWidth(null) + dispWidth;
			}
			Graphics g = backImg.getGraphics();
			g.setColor(bg);
			g.fillRect(0, 0, dispWidth,
			    dispHeight);
			g.drawImage(scrollImg, dispWidth-xpos, topMargin,
			    null);
			try {
				thread.sleep(50);
			} catch (InterruptedException e) {}
			getGraphics().drawImage(backImg, 0, 0, null);
		}
	}

        public String getAppletInfo() {
                return "Banner by Ken Shirriff  shirriff@eng.sun.com";
        }
 
}