--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gnv-artifacts/src/main/java/de/intevation/gnv/chart/AbstractHistogram.java	Fri Sep 28 12:14:00 2012 +0200
@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2010 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.gnv.chart;
+
+import java.util.Locale;
+
+import org.apache.log4j.Logger;
+
+import org.jfree.chart.ChartFactory;
+import org.jfree.chart.ChartTheme;
+import org.jfree.chart.JFreeChart;
+
+import org.jfree.chart.axis.NumberAxis;
+import org.jfree.chart.axis.TickUnitSource;
+
+import org.jfree.chart.plot.PlotOrientation;
+import org.jfree.chart.plot.XYPlot;
+
+import org.jfree.chart.renderer.xy.XYBarRenderer;
+
+/**
+ * This abstract class defines some methods to adjust chart settings after its
+ * creation.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public abstract class AbstractHistogram
+implements            Chart
+{
+    /**
+     * Logger used for logging with Apache log4j.
+     */
+    private Logger logger = Logger.getLogger(AbstractHistogram.class);
+
+    /**
+     * JFreeChart chart stored at this place after chart creation.
+     */
+    protected JFreeChart  chart;
+
+    /**
+     * Labels used for chart title, subtitle, axis description.
+     */
+    protected ChartLabels labels;
+
+    /**
+     * Theme which is used to adjust the styling of this chart.
+     */
+    protected ChartTheme  theme;
+
+    /**
+     * Raw data which should be displayed in the chart.
+     */
+    protected Object[]    data;
+
+    /**
+     * Locale object used for i18n support.
+     */
+    protected Locale     locale;
+
+
+    /**
+     * Constructor for creating histogram charts.
+     *
+     * @param labels See {@link #labels}
+     * @param data See {@link #data}
+     * @param theme See {@link #theme}
+     */
+    public AbstractHistogram(
+        ChartLabels labels, Object[] data, ChartTheme theme
+    ) {
+        this.labels = labels;
+        this.data   = data;
+        this.theme  = theme;
+    }
+
+
+    /**
+     * @see de.intevation.gnv.chart.Chart#generateChart()
+     */
+    public JFreeChart generateChart() {
+
+        if (chart != null)
+            return chart;
+
+        chart = ChartFactory.createHistogram(
+            labels.getTitle(),
+            labels.getDomainAxisLabel(),
+            labels.getRangeAxisLabel(),
+            null,
+            PlotOrientation.VERTICAL,
+            true,
+            false,
+            false);
+
+        applyDatasets();
+
+        theme.apply(chart);
+        adjustPlot();
+        adjustDomainAxis(chart);
+        adjustRangeAxis(chart);
+
+        return chart;
+    }
+
+
+    /**
+     * Method to do some changes in plot settings.
+     */
+    protected void adjustPlot() {
+        XYPlot plot = (XYPlot) chart.getPlot();
+        XYBarRenderer renderer = (XYBarRenderer) plot.getRenderer();
+
+        renderer.setShadowVisible(false);
+        renderer.setSeriesVisibleInLegend(0, false);
+    }
+
+
+    protected void adjustDomainAxis(JFreeChart chart) {
+        XYPlot plot           = (XYPlot) chart.getPlot();
+        NumberAxis domainAxis = (NumberAxis) plot.getDomainAxis();
+
+        TickUnitSource tus    = domainAxis.createStandardTickUnits(locale);
+        domainAxis.setStandardTickUnits(tus);
+    }
+
+
+    protected void adjustRangeAxis(JFreeChart chart) {
+        XYPlot plot           = (XYPlot) chart.getPlot();
+        NumberAxis rangeAxis = (NumberAxis) plot.getRangeAxis();
+
+        TickUnitSource tus    = rangeAxis.createStandardTickUnits(locale);
+        rangeAxis.setStandardTickUnits(tus);
+    }
+
+
+
+
+    /**
+     * This method needs to be implemented by subclasses and should add valid
+     * <code>HistogramDataset</code> objects to the created chart. It is called
+     * by {@link #generateChart} after chart creation.
+     */
+    protected abstract void applyDatasets();
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :