--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/exports/ChartInfoGenerator.java	Wed Jun 01 08:01:07 2011 +0000
@@ -0,0 +1,124 @@
+package de.intevation.flys.exports;
+
+import java.awt.Transparency;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.w3c.dom.Document;
+
+import org.apache.log4j.Logger;
+
+import org.jfree.chart.ChartRenderingInfo;
+import org.jfree.chart.JFreeChart;
+
+import de.intevation.artifacts.Artifact;
+import de.intevation.artifacts.CallContext;
+
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+
+/**
+ * An OutGenerator that generates meta information for charts. A concrete
+ * ChartInfoGenerator need to instantiate a concrete ChartGenerator and dispatch
+ * the methods to that instance. The only thing this ChartInfoGenerator needs
+ * to, is to overrite the generate() method which doesn't write the chart image
+ * to the OutputStream but a Document that contains some meta information of the
+ * created chart.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public abstract class ChartInfoGenerator implements OutGenerator {
+
+    /** The logger used in this generator.*/
+    private static Logger logger =
+        Logger.getLogger(ChartInfoGenerator.class);
+
+
+    /** The OutGenerator that creates the charts.*/
+    protected OutGenerator generator;
+
+    protected OutputStream out;
+
+
+
+    public ChartInfoGenerator(OutGenerator generator) {
+        this.generator = generator;
+    }
+
+
+    /**
+     * Dispatches the operation to the instantiated generator.
+     *
+     * @param request
+     * @param out
+     * @param context
+     */
+    public void init(Document request, OutputStream out, CallContext context) {
+        this.out = out;
+
+        generator.init(request, out, context);
+    }
+
+
+    /**
+     * Dispatches the operation to the instantiated generator.
+     *
+     * @param master
+     */
+    public void setMasterArtifact(Artifact master) {
+        generator.setMasterArtifact(master);
+    }
+
+
+    /**
+     * Dispatches the operation to the instantiated generator.
+     *
+     * @param artifacts
+     * @param facet
+     * @param attr
+     */
+    public void doOut(Artifact artifact, String facet, Document attr) {
+        generator.doOut(artifact, facet, attr);
+    }
+
+
+    /**
+     * This method generates the chart using a concrete ChartGenerator but
+     * doesn't write the chart itself to the OutputStream but a Document that
+     * contains meta information of the created chart.
+     */
+    @Override
+    public void generate()
+    throws IOException
+    {
+        logger.debug("ChartInfoGenerator.generate");
+
+        JFreeChart chart = generateChart();
+
+        int[] size = getSize();
+
+        ChartRenderingInfo info = new ChartRenderingInfo();
+
+        chart.createBufferedImage(size[0], size[1], Transparency.BITMASK, info);
+
+        Document doc = InfoGeneratorHelper.createInfoDocument(chart, info);
+
+        XMLUtils.toStream(doc, out);
+    }
+
+
+    /**
+     * Creates a chart object.
+     *
+     * @return a chart object.
+     */
+    protected abstract JFreeChart generateChart();
+
+    /**
+     * Returns the size of the generated chart.
+     *
+     * @return the size of the generated chart.
+     */
+    protected abstract int[] getSize();
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :