Bug 38477 add delegate methods: OK enabled even if nothing selected
20030604 the OK button is enabled even if nothing is selected in the dialog
org.eclipse.jdt.ui/ui/org/eclipse/jdt/ui/actions/AddDelegateMethodsAction.java
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;
import org.eclipse.jface.window.Window;
import org.eclipse.ui.IEditorPart;
import org.eclipse.ui.IWorkbenchSite;
import org.eclipse.ui.dialogs.ISelectionStatusValidator;
import org.eclipse.ui.help.WorkbenchHelp;
import org.eclipse.jdt.core.Flags;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IField;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jdt.ui.JavaElementLabelProvider;
import org.eclipse.jdt.ui.JavaElementSorter;
import org.eclipse.jdt.internal.corext.codemanipulation.AddDelegateMethodsOperation;
import org.eclipse.jdt.internal.corext.codemanipulation.CodeGenerationSettings;
import org.eclipse.jdt.internal.corext.codemanipulation.AddDelegateMethodsOperation.Methods2Field;
import org.eclipse.jdt.internal.corext.refactoring.util.JavaElementUtil;
import org.eclipse.jdt.internal.corext.util.JavaModelUtil;
import org.eclipse.jdt.internal.corext.util.JdtFlags;
import org.eclipse.jdt.internal.ui.IJavaHelpContextIds;
import org.eclipse.jdt.internal.ui.JavaPlugin;
import org.eclipse.jdt.internal.ui.actions.ActionMessages;
import org.eclipse.jdt.internal.ui.actions.ActionUtil;