small fix

de.bmotionstudio.gef.editor/src/de/bmotionstudio/gef/editor/observer/ListenOperationObject.java

@@ -13,6 +13,12 @@ public class ListenOperationObject extends BindingObject implements Cloneable {
 	private String operationName;
 	private String predicate;
 
+	public ListenOperationObject() {
+		super();
+		this.operationName = "";
+		this.predicate = "";
+	}
+
 	public ListenOperationObject clone() throws CloneNotSupportedException {
 		return (ListenOperationObject) super.clone();
 	}

de.bmotionstudio.gef.editor/src/de/bmotionstudio/gef/editor/observer/ToggleObjectCoordinates.java

@@ -6,16 +6,19 @@
 
 package de.bmotionstudio.gef.editor.observer;
 
-
 public class ToggleObjectCoordinates extends ObserverEvalObject implements
 		Cloneable {
 
 	private String bcontrol;
 	private String x;
 	private String y;
-	private Boolean animate = false;
+	private Boolean animate;
 
 	public ToggleObjectCoordinates() {
+		super();
+		this.x = "";
+		this.y = "";
+		this.animate = false;
 	}
 
 	public ToggleObjectCoordinates(String type, String bcontrol, String x,

de.bmotionstudio.gef.editor/src/de/bmotionstudio/gef/editor/observer/wizard/WizardObserverListenOperationByPredicate.java

@@ -16,6 +16,7 @@ import org.eclipse.core.databinding.observable.list.WritableList;
 import org.eclipse.core.databinding.observable.map.IObservableMap;
 import org.eclipse.jface.databinding.viewers.ObservableListContentProvider;
 import org.eclipse.jface.databinding.viewers.ObservableMapLabelProvider;
+import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.viewers.CellEditor;
 import org.eclipse.jface.viewers.ComboBoxViewerCellEditor;
 import org.eclipse.jface.viewers.EditingSupport;
@@ -314,6 +315,24 @@ public class WizardObserverListenOperationByPredicate extends ObserverWizard {
 
 	@Override
 	protected Boolean prepareToFinish() {
+		if (((ListenOperationByPredicate) getObserver()).getList().size() == 0) {
+			setObserverDelete(true);
+		} else {
+			for (PredicateOperation obj : ((ListenOperationByPredicate) getObserver())
+					.getList()) {
+				if (obj.getOperationName().isEmpty()) {
+					MessageDialog
+							.openError(getShell(), "Please check your entries",
+									"Please check your entries. The operation field must not be empty.");
+					return false;
+				} else if (obj.getAttribute() == null) {
+					MessageDialog
+							.openError(getShell(), "Please check your entries",
+									"Please check your entries. The attribute field must not be empty.");
+					return false;
+				}
+			}
+		}
 		return true;
 	}