franta-hg@1: /* ================================================================
franta-hg@1:  * Cewolf : Chart enabling Web Objects Framework
franta-hg@1:  * ================================================================
franta-hg@1:  *
franta-hg@1:  * Project Info:  http://cewolf.sourceforge.net
franta-hg@1:  * Project Lead:  Guido Laures (guido@laures.de);
franta-hg@1:  *
franta-hg@1:  * (C) Copyright 2002, by Guido Laures
franta-hg@1:  *
franta-hg@1:  * This library is free software; you can redistribute it and/or modify it under the terms
franta-hg@1:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
franta-hg@1:  * either version 2.1 of the License, or (at your option) any later version.
franta-hg@1:  *
franta-hg@1:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
franta-hg@1:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
franta-hg@1:  * See the GNU Lesser General Public License for more details.
franta-hg@1:  *
franta-hg@1:  * You should have received a copy of the GNU Lesser General Public License along with this
franta-hg@1:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
franta-hg@1:  * Boston, MA 02111-1307, USA.
franta-hg@1:  */
franta-hg@1: 
franta-hg@1: package de.laures.cewolf.util;
franta-hg@1: 
franta-hg@1: import java.awt.Color;
franta-hg@1: import java.awt.Font;
franta-hg@1: import java.awt.Graphics;
franta-hg@1: import java.awt.image.BufferedImage;
franta-hg@1: import java.io.IOException;
franta-hg@1: import java.io.OutputStream;
franta-hg@1: import java.io.PrintWriter;
franta-hg@1: import java.io.StringWriter;
franta-hg@1: import java.util.Enumeration;
franta-hg@1: import java.util.StringTokenizer;
franta-hg@1: 
franta-hg@1: import com.sun.image.codec.jpeg.JPEGCodec;
franta-hg@1: import com.sun.image.codec.jpeg.JPEGEncodeParam;
franta-hg@1: import com.sun.image.codec.jpeg.JPEGImageEncoder;
franta-hg@1: 
franta-hg@1: /**
franta-hg@1:  * Some methods to render messages or exceptions into an image.
franta-hg@1:  * @author glaures
franta-hg@1:  */
franta-hg@1: public class RenderingHelper {
franta-hg@1: 	
franta-hg@1: 	private final static int PADDING_X = 5;
franta-hg@1: 	
franta-hg@1: 	public static String renderMessage(String msg, int width, int height, OutputStream out) throws IOException {
franta-hg@1: 		BufferedImage image = ImageHelper.createImage(width, height);
franta-hg@1: 		Graphics gr = image.getGraphics();
franta-hg@1: 		gr.setColor(Color.white);
franta-hg@1: 		gr.fillRect(0, 0, width, height);
franta-hg@1: 		gr.setColor(Color.black);
franta-hg@1: 		gr.drawString(msg, PADDING_X, height/2 - 7);
franta-hg@1: 		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
franta-hg@1: 		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);
franta-hg@1: 		param.setQuality(1.0f, true);
franta-hg@1: 		encoder.encode(image, param);
franta-hg@1: 		return "image/jpeg";
franta-hg@1: 	}
franta-hg@1:     
franta-hg@1: 	public static String renderException(Throwable ex, int width, int height, OutputStream out) throws IOException {
franta-hg@1: 		BufferedImage image = ImageHelper.createImage(width, height);
franta-hg@1: 		Graphics gr = image.getGraphics();
franta-hg@1: 		gr.setColor(Color.white);
franta-hg@1: 		gr.fillRect(0, 0, width, height);
franta-hg@1: 		gr.setColor(Color.red);
franta-hg@1: 		gr.drawString(ex.getClass().getName() + " raised:", PADDING_X, 15);
franta-hg@1: 		gr.drawString(String.valueOf(ex.getMessage()), PADDING_X, 30);
franta-hg@1: 		gr.setColor(Color.black);
franta-hg@1: 		Font stFont = gr.getFont().deriveFont(9f);
franta-hg@1: 		gr.setFont(stFont);
franta-hg@1: 		drawStackTrace(gr, PADDING_X, 50, ex);
franta-hg@1: 		JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
franta-hg@1: 		JPEGEncodeParam param = encoder.getDefaultJPEGEncodeParam(image);
franta-hg@1: 		param.setQuality(1.0f, true);
franta-hg@1: 		encoder.encode(image, param);
franta-hg@1: 		return "image/jpeg";
franta-hg@1: 	}
franta-hg@1:     
franta-hg@1:     private static void drawStackTrace(Graphics gr, int x, int y, Throwable ex) {
franta-hg@1:         final int linePadding = 4;
franta-hg@1:         int lineHeight = gr.getFont().getSize() + linePadding;
franta-hg@1:         int currY = y;
franta-hg@1:         Enumeration lines = new StringTokenizer(getStackTrace(ex), "\n", false);
franta-hg@1:         while (lines.hasMoreElements()) {
franta-hg@1:             gr.drawString(((String)lines.nextElement()).trim(), x, currY);
franta-hg@1:             currY += lineHeight;
franta-hg@1:         }
franta-hg@1:     }
franta-hg@1:     
franta-hg@1:     private static String getStackTrace(Throwable t) {
franta-hg@1:         StringWriter sw = new StringWriter();
franta-hg@1:         PrintWriter pw = new PrintWriter(sw);
franta-hg@1:         t.printStackTrace(pw);
franta-hg@1:         pw.close();
franta-hg@1:         return sw.getBuffer().toString();
franta-hg@1:     }
franta-hg@1:     
franta-hg@1: }