--- a/flys-artifacts/ChangeLog	Mon Mar 28 09:17:25 2011 +0000
+++ b/flys-artifacts/ChangeLog	Mon Mar 28 10:48:27 2011 +0000
@@ -1,3 +1,10 @@
+2011-03-28  Ingo Weinzierl <ingo@intevation.de>
+
+	* src/main/java/de/intevation/flys/exports/ChartExportHelper.java:
+	  New. A helper class to exports charts.
+
+	* pom.xml: Added dependencies to iText, Batik and JFreeChart.
+
 2011-03-28	Sascha L. Teichmann	<sascha.teichmann@intevation.de>
 
 	* src/main/java/de/intevation/flys/artifacts/model/GaugesFactory.java:

--- a/flys-artifacts/pom.xml	Mon Mar 28 09:17:25 2011 +0000
+++ b/flys-artifacts/pom.xml	Mon Mar 28 10:48:27 2011 +0000
@@ -55,5 +55,25 @@
       <artifactId>flys-backend</artifactId>
       <version>1.0-SNAPSHOT</version>
     </dependency>
+    <dependency>
+      <groupId>jfree</groupId>
+      <artifactId>jfreechart</artifactId>
+      <version>1.0.13</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.xmlgraphics</groupId>
+      <artifactId>batik-dom</artifactId>
+      <version>1.7</version>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.xmlgraphics</groupId>
+      <artifactId>batik-svggen</artifactId>
+      <version>1.7</version>
+    </dependency>
+    <dependency>
+      <groupId>com.lowagie</groupId>
+      <artifactId>itext</artifactId>
+      <version>2.1.7</version>
+    </dependency>
   </dependencies>
 </project>

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/exports/ChartExportHelper.java	Mon Mar 28 10:48:27 2011 +0000
@@ -0,0 +1,307 @@
+/*
+ * Copyright (c) 2011 by Intevation GmbH
+ *
+ * This program is free software under the LGPL (>=v2.1)
+ * Read the file LGPL.txt coming with the software for details
+ * or visit http://www.gnu.org/licenses/ if it does not exist.
+ */
+package de.intevation.flys.exports;
+
+import com.lowagie.text.Document;
+import com.lowagie.text.DocumentException;
+import com.lowagie.text.PageSize;
+import com.lowagie.text.Rectangle;
+
+import com.lowagie.text.pdf.PdfContentByte;
+import com.lowagie.text.pdf.PdfTemplate;
+import com.lowagie.text.pdf.PdfWriter;
+
+import java.awt.Graphics2D;
+import java.awt.Transparency;
+
+import java.awt.geom.Rectangle2D.Double;
+
+import java.awt.geom.Rectangle2D;
+
+import java.awt.image.BufferedImage;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.UnsupportedEncodingException;
+
+import javax.imageio.ImageIO;
+
+import org.apache.batik.svggen.SVGGraphics2D;
+import org.apache.batik.svggen.SVGGraphics2DIOException;
+
+import org.apache.log4j.Logger;
+
+import org.jfree.chart.JFreeChart;
+
+import de.intevation.artifacts.CallContext;
+
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+
+/**
+ * This class is a helper class which supports some methods to export charts
+ * into specific formats.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public class ChartExportHelper {
+
+    /**
+     * Constant field to define A4 as default page size.
+     */
+    private static final String  DEFAULT_PAGE_SIZE = "A4";
+
+    /**
+     * Constant field to define UTF-8 as default encoding.
+     */
+    private static final String  DEFAULT_ENCODING  = "UTF-8";
+
+    /**
+     * Logger used for logging with log4j.
+     */
+    private static Logger log = Logger.getLogger(ChartExportHelper.class);
+
+
+    /**
+     * A method to export a <code>JFreeChart</code> as image to an
+     * <code>OutputStream</code> with a given format, width and height.
+     *
+     * @param out OutputStream
+     * @param chart JFreeChart object to be exported.
+     * @param format Format (e.g. png, gif, jpg)
+     * @param width Width, the image used to be
+     * @param height Height, the image used to be
+     *
+     * @throws IOException if writing image to OutputStream failed.
+     */
+    public static void exportImage(
+        OutputStream out,
+        JFreeChart chart,
+        String format,
+        int width,
+        int height
+    )
+    throws IOException
+    {
+        log.info("export chart as png");
+
+        ImageIO.write(
+            chart.createBufferedImage(
+                width, height, Transparency.BITMASK, null
+            ),
+            format,
+            out
+        );
+    }
+
+
+    /**
+     * A method to export a <code>JFreeChart</code> as SVG to an
+     * <code>OutputStream</code>.
+     *
+     * @param out OutputStream
+     * @param chart JFreeChart to be exported
+     * @param encoding Encoding, defaults to {@link #DEFAULT_ENCODING} if null
+     * @param width Width the svg used to be
+     * @param height Height the svg used to be
+     */
+    public static void exportSVG(
+        OutputStream out,
+        JFreeChart   chart,
+        String       encoding,
+        int          width,
+        int          height
+    ) {
+        log.info("export chart as svg");
+
+        if (encoding == null)
+            encoding = DEFAULT_ENCODING;
+
+        org.w3c.dom.Document document = XMLUtils.newDocument();
+        SVGGraphics2D        graphics = new SVGGraphics2D(document);
+
+        chart.draw(graphics, new Rectangle2D.Double(0.0D, 0.0D,width,height));
+
+        try {
+            graphics.stream(new OutputStreamWriter(out, encoding));
+        }
+        catch (SVGGraphics2DIOException svge) {
+            log.error("Error while writing svg export to output stream.", svge);
+        }
+        catch (UnsupportedEncodingException uee) {
+            log.error("Unsupported encoding: " + encoding, uee);
+        }
+    }
+
+
+    /**
+     * A method to export a <code>JFreeChart</code> as PDF to an
+     * <code>OutputStream</code>.
+     *
+     * @param out OutputStream
+     * @param chart JFreeChart
+     * @param pageFormat String to specify a page format, {@link
+     * #DEFAULT_PAGE_SIZE} is used if no pageFormat is given
+     * @param landscape If this is true, the pdf is delivered in landscape
+     * format
+     * @param marginLeft Space to left border
+     * @param marginRight Space to right border
+     * @param marginTop Space to upper border
+     * @param marginBottom Space to lower border
+     */
+    public static void exportPDF(
+        OutputStream out,
+        JFreeChart   chart,
+        String       pageFormat,
+        float        marginLeft,
+        float        marginRight,
+        float        marginTop,
+        float        marginBottom,
+        CallContext  context
+    ) {
+        log.info("export chart as pdf.");
+
+        if (pageFormat == null)
+            pageFormat = DEFAULT_PAGE_SIZE;
+
+        // max size of the chart
+        Rectangle page = PageSize.getRectangle(pageFormat);
+        float pageWidth  = page.getWidth();
+        float pageHeight = page.getHeight();
+
+        // the chart width
+        int chartWidth  = (Integer) context.getContextValue("chart.width");
+        int chartHeight = (Integer) context.getContextValue("chart.height");
+
+        boolean landscape = chartWidth > chartHeight ? true : false;
+
+        float width  = 0;
+        float height = 0;
+        if (landscape) {
+            width  = pageHeight;
+            height = pageWidth;
+        }
+        else {
+            width  = pageWidth;
+            height = pageHeight;
+        }
+
+        float spaceX = width  - marginLeft - marginRight;
+        if (chartWidth > spaceX) {
+            log.warn("Width of the chart is too big for pdf -> resize it now.");
+            double ratio = ((double)spaceX) / chartWidth;
+            chartWidth  *= ratio;
+            chartHeight *= ratio;
+            log.debug("Resized chart to " + chartWidth + "x" + chartHeight);
+        }
+
+        float spaceY = height - marginTop  - marginBottom;
+        if (chartHeight > spaceY) {
+            log.warn("Height of the chart is too big for pdf -> resize it now.");
+            double ratio = ((double)spaceY) / chartHeight;
+            chartWidth  *= ratio;
+            chartHeight *= ratio;
+            log.debug("Resized chart to " + chartWidth + "x" + chartHeight);
+        }
+
+        Document document = null;
+        if (landscape) {
+            document = new Document(page.rotate());
+            log.debug("Create landscape pdf.");
+        }
+        else
+            document = new Document(page);
+
+        try {
+            PdfWriter writer = PdfWriter.getInstance(document, out);
+
+            document.addSubject(chart.getTitle().getText());
+            document.addCreationDate();
+            document.open();
+
+            PdfContentByte content  = writer.getDirectContent();
+
+            PdfTemplate template = content.createTemplate(width, height);
+            Graphics2D  graphics = template.createGraphics(width, height);
+
+            double[] origin = getCenteredAnchor(
+                marginLeft, marginRight, marginBottom, marginTop,
+                width, height,
+                chartWidth, chartHeight);
+
+            Rectangle2D area = new Rectangle2D.Double(
+                origin[0], origin[1], chartWidth, chartHeight);
+
+            chart.draw(graphics, area);
+            graphics.dispose();
+            content.addTemplate(template, 0f, 0f);
+        }
+        catch (DocumentException de) {
+            log.error("Error while exporting chart to pdf.", de);
+        }
+        finally {
+            document.close();
+        }
+    }
+
+
+    /**
+     * This method returns the anchor of the chart so that the chart is centered
+     * according to the given parameters.
+     *
+     * @param mLeft Left margin
+     * @param mRight Right margin
+     * @param mBottom Bottom margin
+     * @param mTop Top margin
+     * @param width The complete width of the drawing area.
+     * @param height The complete height of the drawing area.
+     * @param chartWidth The width of the chart.
+     * @param chartHeight The height of the chart.
+     *
+     * @return an array that contains the anchor for a chart with the given
+     * parameters. The first value is the x point, the second value is the y
+     * point.
+     */
+    public static double[] getCenteredAnchor(
+        double mLeft,      double mRight,      double mBottom, double mTop,
+        double width,      double height,
+        double chartWidth, double chartHeight
+    ) {
+        if (log.isDebugEnabled()) {
+            log.debug("Calculate centered origin...");
+            log.debug("-> PDF width    : " + width);
+            log.debug("-> PDF height   : " + height);
+            log.debug("-> Chart width  : " + chartWidth);
+            log.debug("-> Chart height : " + chartHeight);
+            log.debug("-> margin left  : " + mLeft);
+            log.debug("-> margin right : " + mRight);
+            log.debug("-> margin bottom: " + mBottom);
+            log.debug("-> margin top   : " + mTop);
+        }
+
+        double[] origin = new double[2];
+
+        double centerX = width  / 2;
+        double centerY = height / 2;
+
+        origin[0] = centerX - chartWidth / 2;
+        origin[1] = centerY - chartHeight / 2;
+
+        origin[0] = origin[0] >= mLeft ? origin[0] : mLeft;
+        origin[1] = origin[1] >= mTop ? origin[1] : mTop;
+
+        if (log.isDebugEnabled()) {
+            log.debug("==> centered left origin: " + origin[0]);
+            log.debug("==> centered top  origin: " + origin[1]);
+        }
+
+        return origin;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :