EDIT

import eu.etaxonomy.taxeditor.editor.view.descriptive.DescriptiveContentProvider;

import eu.etaxonomy.taxeditor.editor.view.descriptive.DescriptiveLabelProvider;

import eu.etaxonomy.taxeditor.editor.view.descriptive.DescriptiveViewerSorter;

import eu.etaxonomy.taxeditor.editor.view.media.e4.MediaViewPartE4;

import eu.etaxonomy.taxeditor.event.WorkbenchEventConstants;

import eu.etaxonomy.taxeditor.model.FeatureNodeContainer;

        treeViewer.setContentProvider(provider);

        treeViewer.setLabelProvider(new DescriptiveLabelProvider());

        treeViewer.setSorter(new DescriptiveViewerSorter());

        treeViewer.setAutoExpandLevel(2);

        Transfer[] transfers = new Transfer[] { DescriptionElementTransfer.getInstance() };

        treeViewer.addDragSupport(dndOperations, transfers, new DescriptionElementDragListener(

        viewer.addSelectionChangedListener(selectionChangedListener);

        DescriptionElementDropAdapter dropListener = new DescriptionElementDropAdapter(viewer);

        ContextInjectionFactory.inject(dropListener, context);

        treeViewer.addDropSupport(dndOperations, transfers,

                dropListener);

        //create context menu