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

 * 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();

    }

}