/* ================================================================

  * Cewolf : Chart enabling Web Objects Framework

  * ================================================================

  *

  * Project Info:  http://cewolf.sourceforge.net

  * Project Lead:  Guido Laures (guido@laures.de);

  *

  * (C) Copyright 2002, by Guido Laures

  *

  * 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., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  */

 package de.laures.cewolf.util;

 import java.awt.Color;

 import java.awt.Font;

 import java.awt.Graphics;

 import java.awt.image.BufferedImage;

 import java.io.IOException;

 import java.io.OutputStream;

 import java.io.PrintWriter;

 import java.io.StringWriter;

 import java.util.Enumeration;

 import java.util.StringTokenizer;

 import com.sun.image.codec.jpeg.JPEGCodec;

 import com.sun.image.codec.jpeg.JPEGEncodeParam;

 import com.sun.image.codec.jpeg.JPEGImageEncoder;

 /**

  * Some methods to render messages or exceptions into an image.

  * @author glaures

  */

 public class RenderingHelper {

 	private final static int PADDING_X = 5;

 	public static String renderMessage(String msg, int width, int height, OutputStream out) throws IOException {

 		BufferedImage image = ImageHelper.createImage(width, height);

 		Graphics gr = image.getGraphics();

 		gr.setColor(Color.white);

 		gr.fillRect(0, 0, width, height);

 		gr.setColor(Color.black);

 		gr.drawString(msg, PADDING_X, height/2 - 7);

 		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

 		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);

 		param.setQuality(1.0f, true);

 		encoder.encode(image, param);

 		return "image/jpeg";

 	}

 	public static String renderException(Throwable ex, int width, int height, OutputStream out) throws IOException {

 		BufferedImage image = ImageHelper.createImage(width, height);

 		Graphics gr = image.getGraphics();

 		gr.setColor(Color.white);

 		gr.fillRect(0, 0, width, height);

 		gr.setColor(Color.red);

 		gr.drawString(ex.getClass().getName() + " raised:", PADDING_X, 15);

 		gr.drawString(String.valueOf(ex.getMessage()), PADDING_X, 30);

 		gr.setColor(Color.black);

 		Font stFont = gr.getFont().deriveFont(9f);

 		gr.setFont(stFont);

 		drawStackTrace(gr, PADDING_X, 50, ex);

 		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);

 		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);

 		param.setQuality(1.0f, true);

 		encoder.encode(image, param);

 		return "image/jpeg";

 	}

     private static void drawStackTrace(Graphics gr, int x, int y, Throwable ex) {

         final int linePadding = 4;

         int lineHeight = gr.getFont().getSize() + linePadding;

         int currY = y;

         Enumeration lines = new StringTokenizer(getStackTrace(ex), "\n", false);

         while (lines.hasMoreElements()) {

             gr.drawString(((String)lines.nextElement()).trim(), x, currY);

             currY += lineHeight;

         }

     }

     private static String getStackTrace(Throwable t) {

         StringWriter sw = new StringWriter();

         PrintWriter pw = new PrintWriter(sw);

         t.printStackTrace(pw);

         pw.close();

         return sw.getBuffer().toString();

     }

 }