EDIT

import org.eclipse.core.runtime.IProgressMonitor;

import org.eclipse.core.runtime.IStatus;

import org.eclipse.core.runtime.Status;

import org.eclipse.core.runtime.jobs.Job;

import org.eclipse.jface.viewers.ISelection;

import org.eclipse.jface.viewers.StructuredSelection;

import org.eclipse.swt.widgets.Display;

import eu.etaxonomy.cdm.model.description.PolytomousKey;

import eu.etaxonomy.taxeditor.editor.EditorUtil;

import eu.etaxonomy.taxeditor.model.MessagingUtils;

import eu.etaxonomy.taxeditor.navigation.NavigationUtil;

import eu.etaxonomy.taxeditor.navigation.key.polytomous.PolytomousKeyViewLabels;

import eu.etaxonomy.taxeditor.navigation.key.polytomous.PolytomousKeyViewPart;

import eu.etaxonomy.taxeditor.navigation.key.polytomous.e4.handler.RemotingEditPolytomousKeyNodesHandlerE4;

        PolytomousKeyViewPart view = (PolytomousKeyViewPart) NavigationUtil.getView(PolytomousKeyViewPart.ID, false);

        ISelection selection = view.getSite().getSelectionProvider().getSelection();

        if(selection instanceof StructuredSelection){

            final StructuredSelection structuredSelection = (StructuredSelection) selection;

            Job job = new Job(RemotingEditPolytomousKeyNodesHandlerE4.OPENING_POLYTOMOUS_KEYS){

                @Override

                protected IStatus run(IProgressMonitor monitor) {

                    monitor.beginTask(RemotingEditPolytomousKeyNodesHandlerE4.OPENING_POLYTOMOUS_KEYS, structuredSelection.size());

                    for(final Object selectedObject : structuredSelection.toArray()){

                        if(selectedObject instanceof PolytomousKey){

                            Display.getDefault().asyncExec(new Runnable(){

                                @Override

                                public void run() {

                                    try {

                                        PolytomousKey key = (PolytomousKey) selectedObject;

                                    EditorUtil.openPolytomousKey(key.getUuid());

                                    } catch(Exception ex) {

                                        MessagingUtils.warningDialog(PolytomousKeyViewLabels.ERROR_OPENING_KEY_EDITOR_MESSAGE,

                                                event.getTrigger(),

                                                ex.getLocalizedMessage());

                                        ex.printStackTrace();

                                    }

                                }

                            });

                            monitor.worked(1);

                        }

                    }

                    monitor.done();

                    return Status.OK_STATUS;

                }

            };

            job.setPriority(Job.SHORT);

            job.schedule();

        }