--- a/flys-artifacts/src/main/java/de/intevation/flys/exports/ChartGenerator.java	Fri Oct 26 16:40:09 2012 +0200
+++ b/flys-artifacts/src/main/java/de/intevation/flys/exports/ChartGenerator.java	Fri Oct 26 16:41:36 2012 +0200
@@ -71,6 +71,11 @@
  * The base class for chart creation. It should provide some basic things that
  * equal in all chart types.
  *
+ * Annotations are added as FLYSAnnotations and come in mutliple basic forms:
+ * TextAnnotations are labels somewhere in data space, StickyAnnotations are
+ * labels of a slice or line in one data dimension (i.e. visualized as label
+ * on a single axis).
+ *
  * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
  */
 public abstract class ChartGenerator implements OutGenerator {
@@ -1458,8 +1463,10 @@
 
     /**
      * Returns the X-Axis range as String array from request document.
+     * If the (x|y)range elements are not found in request document, return
+     * null (i.e. not zoomed).
      *
-     * @return a String array with [lower, upper].
+     * @return a String array with [lower, upper], null if not in document.
      */
     protected String[] getDomainAxisRangeFromRequest() {
         Element xrange = (Element)XMLUtils.xpath(
@@ -1481,6 +1488,9 @@
     }
 
 
+    /** Returns null if the (x|y)range-element was not found in request document.
+     * This usally means that the axis are not manually zoomed, i.e. showing
+     * full data extent. */
     protected String[] getValueAxisRangeFromRequest() {
         Element yrange = (Element)XMLUtils.xpath(
             request,