diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
index a40d55d8..67d102e2 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ArchiveWidget.java
@@ -20,7 +20,6 @@
  * SOFTWARE.
  *******************************************************************************/
 
-
 package org.opt4j.viewer;
 
 import java.awt.BorderLayout;
@@ -259,18 +258,22 @@ public void stateChanged(ChangeEvent e) {
 
 			@Override
 			public void columnAdded(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnMarginChanged(ChangeEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnMoved(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
 			public void columnRemoved(TableColumnModelEvent arg0) {
+				// nothing to be done
 			}
 
 			@Override
@@ -342,7 +345,7 @@ protected void sortIndividiualMouseListeners() {
 	 */
 	@Override
 	public synchronized void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	protected boolean updateOrder() {
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
index aefe96fd..1054cfcf 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotData.java
@@ -19,7 +19,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *******************************************************************************/
- 
+
 package org.opt4j.viewer;
 
 import java.awt.geom.Point2D;
@@ -79,7 +79,7 @@ protected static class PlotDataObjective {
 		protected final List<Point2D.Double> meanValues = new CopyOnWriteArrayList<Point2D.Double>();
 		protected final int MAXVALUES = 2000;
 
-		final Set<Double> currentIteration = new HashSet<Double>();
+		protected final Set<Double> currentIteration = new HashSet<Double>();
 
 		PlotDataObjective(Objective objective) {
 			this.objective = objective;
@@ -98,7 +98,7 @@ public void update(Objectives objectives) {
 			}
 		}
 
-		protected synchronized void simplify(List<java.awt.geom.Point2D.Double> values) {
+		protected synchronized void simplify(List<Point2D.Double> values) {
 			if (values.size() > MAXVALUES) {
 				List<Point2D.Double> copy = new ArrayList<Point2D.Double>(values);
 
@@ -167,17 +167,15 @@ public void complete(int iteration) {
 			}
 		}
 
-		private void addValue(double min, List<java.awt.geom.Point2D.Double> points, int iteration) {
-			if (!Double.isInfinite(min)) {
-				if (points.isEmpty() || points.get(points.size() - 1).getY() != min) {
-					if (!points.isEmpty()) {
-						Point2D.Double steppoint = new Point2D.Double(iteration, points.get(points.size() - 1).getY());
-						points.add(steppoint);
-					}
-
-					Point2D.Double point = new Point2D.Double(iteration, min);
-					points.add(point);
+		private void addValue(double min, List<Point2D.Double> points, int iteration) {
+			if (!Double.isInfinite(min) && (points.isEmpty() || points.get(points.size() - 1).getY() != min)) {
+				if (!points.isEmpty()) {
+					Point2D.Double steppoint = new Point2D.Double(iteration, points.get(points.size() - 1).getY());
+					points.add(steppoint);
 				}
+
+				Point2D.Double point = new Point2D.Double(iteration, min);
+				points.add(point);
 			}
 		}
 	}
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
index 11bddec3..d2f3234a 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ConvergencePlotWidget.java
@@ -211,7 +211,7 @@ public JPanel getPanel() {
 	 */
 	@Override
 	public void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
index a492a43a..98bb9953 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/ParetoPlotWidget.java
@@ -217,7 +217,7 @@ public void registerAtObjectivesMonitor(ObjectivesMonitor objectivesMonitor) {
 	 */
 	@Override
 	public void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
index dcb015eb..296e35ef 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/PopulationWidget.java
@@ -252,7 +252,7 @@ protected final JTable getTable() {
 	 */
 	@Override
 	public synchronized void init(Viewport viewport) {
-
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
index 5e5ac1d6..4c801caa 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/StatusBar.java
@@ -168,6 +168,7 @@ public void iterationComplete(int iteration) {
 	 */
 	@Override
 	public void optimizationStarted(Optimizer optimizer) {
+		// nothing to be done
 	}
 
 	/*
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
index 68012736..12c409bc 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewer.java
@@ -168,6 +168,7 @@ public void windowClosing(WindowEvent e) {
 					break;
 				default:
 					control.doStop();
+					break;
 				}
 				frame.dispose();
 			}
diff --git a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
index b649824e..43b29527 100644
--- a/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
+++ b/opt4j-viewer/src/main/java/org/opt4j/viewer/Viewport.java
@@ -56,14 +56,6 @@ public class Viewport {
 
 	protected final Map<Widget, JInternalFrame> widgets = new HashMap<Widget, JInternalFrame>();
 
-	/**
-	 * Constructs a {@link Viewport} for {@link Widget}s.
-	 * 
-	 */
-	public Viewport() {
-
-	}
-
 	/**
 	 * Initialization. This method has to be called once after construction.
 	 */