--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/states/DGMSelect.java	Mon Dec 19 09:08:40 2011 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/states/DGMSelect.java	Mon Dec 19 10:01:17 2011 +0000
@@ -6,12 +6,16 @@
 
 import org.apache.log4j.Logger;
 
+import de.intevation.artifacts.Artifact;
 import de.intevation.artifacts.CallContext;
 
 import de.intevation.artifacts.common.utils.XMLUtils.ElementCreator;
 
+import de.intevation.flys.model.DGM;
+import de.intevation.flys.model.River;
+
 import de.intevation.flys.artifacts.FLYSArtifact;
-import de.intevation.flys.model.DGM;
+import de.intevation.flys.utils.FLYSUtils;
 
 
 /**
@@ -21,6 +25,11 @@
 
     private static final Logger logger = Logger.getLogger(DGMSelect.class);
 
+    public static final String ERR_EMPTY         = "error_no_dgm_selected";
+    public static final String ERR_INVALID_DGM   = "error_invalid_dgm_selected";
+    public static final String ERR_BAD_DGM_RANGE = "error_bad_dgm_range";
+    public static final String ERR_BAD_DGM_RIVER = "error_bad_dgm_river";
+
 
     @Override
     protected String getUIProvider() {
@@ -66,5 +75,66 @@
 
         return "";
     }
+
+
+    @Override
+    public boolean validate(Artifact artifact)
+    throws IllegalArgumentException
+    {
+        FLYSArtifact flys = (FLYSArtifact) artifact;
+
+        DGM dgm = getDGM(flys);
+
+        if (dgm == null) {
+            throw new IllegalArgumentException(ERR_INVALID_DGM);
+        }
+
+        double l = dgm.getLower().doubleValue();
+        double u = dgm.getUpper().doubleValue();
+
+        double[] range = FLYSUtils.getKmFromTo(flys);
+
+        if (range[0] < l || range[0] > u || range[1] < l || range[1] > u) {
+            throw new IllegalArgumentException(ERR_BAD_DGM_RANGE);
+        }
+
+        River selectedRiver = FLYSUtils.getRiver(flys);
+        River dgmRiver      = dgm.getRiver();
+
+        if (selectedRiver != dgmRiver) {
+            throw new IllegalArgumentException(ERR_BAD_DGM_RIVER);
+        }
+
+        return true;
+    }
+
+
+    /**
+     * Returns the DGM specified in the parameters of <i>flys</i>.
+     *
+     * @param flys The FLYSArtifact that knows the ID of a DGM.
+     *
+     * @throws IllegalArgumentException If the FLYSArtifact doesn't know the ID
+     * of a DGM.
+     *
+     * @return the DGM specified by FLYSArtifact's parameters.
+     */
+    public static DGM getDGM(FLYSArtifact flys)
+    throws IllegalArgumentException
+    {
+        try {
+            Integer dgmId = flys.getDataAsInteger("dgm");
+            if (dgmId == null) {
+                throw new IllegalArgumentException(ERR_EMPTY);
+            }
+
+            logger.debug("Found selected dgm: '" + dgmId + "'");
+
+            return DGM.getDGM(dgmId);
+        }
+        catch (NumberFormatException nfe) {
+            throw new IllegalArgumentException(ERR_INVALID_DGM);
+        }
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :