Bug fix issue 'No quality data generated'

New HydraulicAndQualitySim class to simulate hydraulic and Water quality
analysis in order to fill the water quality data in output.

It fixes the issue:
#4

Author: ahuarte47

src/org/addition/epanet/hydraulic/HydraulicAndQualitySim.java

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2012  Addition, Lda. (addition at addition dot pt)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see http://www.gnu.org/licenses/.
+ */
+package org.addition.epanet.hydraulic;
+
+import java.io.IOException;
+import java.util.logging.Logger;
+
+import org.addition.epanet.hydraulic.io.AwareStep;
+import org.addition.epanet.network.Network;
+import org.addition.epanet.network.PropertiesMap;
+import org.addition.epanet.quality.QualitySim;
+import org.addition.epanet.util.ENException;
+
+/**
+ * Hybrid Hydraulic and Water Quality simulation class.
+ */
+public class HydraulicAndQualitySim extends HydraulicSim {
+
+    /**
+     * Optional related QualitySim when Water Quality analysis is needed.
+     */
+    private QualitySim qualitySim;
+
+    /**
+     * Init hydraulic simulation, preparing the linear solver and the hydraulic structures wrappers.
+     *
+     * @param net Hydraulic network reference.
+     * @param log Logger reference.
+     * @throws ENException
+     */
+    public HydraulicAndQualitySim(Network net, Logger log) throws ENException {
+        super(net, log);
+        if (!net.getPropertiesMap().getQualflag().equals(PropertiesMap.QualType.NONE)) qualitySim = new QualitySim(net, log);
+    }
+
+    /**
+     * Write the simulation results to current output.
+     */
+    @Override
+    protected void writeSimulationOutput() throws ENException, IOException {
+        if (simulationOutput != null && qualitySim != null) {
+            AwareStep.writeHydAndQual(simulationOutput, this, qualitySim, Rtime-Htime, Htime);
+            return;
+        }
+        super.writeSimulationOutput();
+    }
+
+    /**
+     * Finds length of next time step & updates tank levels and rule-based control actions.
+     */
+    @Override
+    protected long nextHyd() throws ENException, IOException {
+        long hydstep = super.nextHyd();
+
+        if (qualitySim != null) {
+            for (long i = 0, qstep = pMap.getQstep(), numQsteps = hydstep/qstep; i < numQsteps; i++) {
+                qualitySim.simulateSingleStep(nNodes, nLinks, qstep);
+            }
+        }
+        return hydstep;
+    }
+}

src/org/addition/epanet/hydraulic/HydraulicSim.java

@@ -686,13 +686,20 @@ private void computeDemands() throws ENException {
     }
 
     /**
-     * Finds length of next time step & updates tank levels and rule-based contol actions.
+     * Write the simulation results to current output.
+     */
+    protected void writeSimulationOutput() throws ENException, IOException {
+        if (simulationOutput != null)
+            AwareStep.write(simulationOutput, this, Htime);
+    }
+
+    /**
+     * Finds length of next time step & updates tank levels and rule-based control actions.
      */
     protected long nextHyd() throws ENException, IOException {
         long hydstep = 0;
 
-        if (simulationOutput != null)
-            AwareStep.write(simulationOutput, this, Htime);
+        writeSimulationOutput();
 
         if (Htime < pMap.getDuration())
             hydstep = timeStep();