--- branches/2.0-RC1/src/skrueger/AttributeMetadata.java	2009/12/09 14:15:53	604
+++ branches/2.0-RC2/src/skrueger/AttributeMetadata.java	2010/02/05 15:21:33	678
@@ -29,7 +29,7 @@
  ******************************************************************************/
 package skrueger;
 
-import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.List;
 
 import org.apache.log4j.Logger;
@@ -75,9 +75,9 @@
 	/**
 	 * Allows to define general NODATA values for an attribute. e.g. -9999 can
 	 * be set and will always be interpreted as NULL internally and will usually
-	 * be ignored. TODO not implemented yet
+	 * be ignored. This overcomes the problem, that 
 	 **/
-	protected List<Object> nodataValues = new ArrayList<Object>();
+	protected HashSet<Object> nodataValues = new HashSet<Object>();
 
 	/** Translation of the attribute's title **/
 	protected Translation title = new Translation();
@@ -137,6 +137,25 @@
 		this.visible = visible;
 		this.unit = unit;
 	}
+	
+
+	/**
+	 * Creates an {@link AttributeMetadata} object with the following
+	 * information
+	 * 
+	 * @param colIdx
+	 *            The column index of this attribute in the underlying
+	 *            table/dbf/etc...
+	 * @param visible
+	 *            Shall this attribute be displayed or hidden from the user?
+	 * @param unit
+	 *            {@link String} of the unit that the information is in
+	 */
+	public AttributeMetadata(final Name name, final Boolean visible, final String unit) {
+		this.setName(name);
+		this.visible = visible;
+		this.unit = unit;
+	}
 
 	/**
 	 * Creates a new visible {@link AttributeMetadata}
@@ -223,13 +242,16 @@
 		amd.setFunctionX(getFunctionX());
 		amd.setFunctionA(getFunctionA());
 
-		for (final Object nodataValue : getNodataValues()) {
-			amd.getNodataValues().add(nodataValue);
-		}
+		amd.setNodataValues(getNodataValues());
 
 		return amd;
 	}
 
+	// only to be used by copyTo()
+	private void setNodataValues(HashSet<Object> nodataValues2) {
+		nodataValues = nodataValues2;
+	}
+
 	public Translation getDesc() {
 		return desc;
 	}
@@ -256,7 +278,7 @@
 		return name;
 	}
 
-	public List<Object> getNodataValues() {
+	public HashSet<Object> getNodataValues() {
 		return nodataValues;
 	}
 
@@ -319,8 +341,12 @@
 		this.name = name;
 	}
 
-	public void setNodataValues(final List<Object> nodataValues) {
-		this.nodataValues = nodataValues;
+	public void addNodataValue(Object nodataValue) {
+		this.nodataValues.add(nodataValue);
+	}
+	
+	public void removeNodataValue(Object nodataValue) {
+		this.nodataValues.remove(nodataValue);
 	}
 
 	public void setTitle(final Translation title) {
@@ -364,4 +390,16 @@
 		sb.append("title="+getTitle().toString());
 		return sb.toString();
 	}
+
+	/**
+	 * Takes any value object and checks it against the NODATA values. If the
+	 * value equals a NODATA value, <code>null</code> is returned. Otherwise the
+	 * same object is returned.
+	 * 
+	 * Note: This method is called often.
+	 */
+	public Object fiterNodata(final Object value) {
+		if (nodataValues.contains(value)) return null;
+		return value;
+	}
 }