EDIT

import eu.etaxonomy.taxeditor.editor.CdmEntitySessionInput;

import eu.etaxonomy.taxeditor.editor.view.derivate.DerivateView;

        	IEditorPart editor = null;

            if (input instanceof CdmEntitySessionInput) {

        } else if (e4WrappedPart instanceof DerivateView){

        	 DerivateView view = (DerivateView) e4WrappedPart;

                 ISelection selection = mediaView.getViewer().getSelection();

                 if (selection instanceof TreeSelection) {

                     TreePath[] paths = ((TreeSelection) selection).getPaths();

                     int count = paths[0].getSegmentCount();

                     DescriptionBase description = null;

                     for (int i = 0; i < count; i++ ) {

                         if (paths[0].getSegment(i) instanceof DescriptionBase) {

                             description = (DescriptionBase) paths[0].getSegment(i);

                             break;

                         }

                     }

                     // TODO use undo context specific to editor

                     MediaDeletionConfigurator config = new MediaDeletionConfigurator();

                     config.setDeleteFromDescription(true);

                     config.setOnlyRemoveFromGallery(false);

                     if (description instanceof SpecimenDescription){

                     	config.setDeleteFrom(((SpecimenDescription)description).getDescribedSpecimenOrObservation());

                     } else if (description instanceof TaxonDescription){

                     	config.setDeleteFrom(((TaxonDescription)description).getTaxon());

                     }else if (description instanceof TaxonNameDescription){

                     	config.setDeleteFrom(((TaxonNameDescription)description).getTaxonName());

                     }

                     DeleteConfiguratorDialog dialog;

                     dialog = new DeleteConfiguratorDialog(config, shell, Messages.DeleteMediaHandler_CONFIRM,  null,  Messages.DeleteMediaHandler_CONFIRM_MESSAGE, MessageDialog.WARNING, new String[] { Messages.DeleteMediaHandler_DELETE, Messages.DeleteMediaHandler_SKIP }, 0);

                     int result_dialog= dialog.open();

                     if (result_dialog != IStatus.OK){

                         return;

                     }

                     AbstractPostOperation<?> operation = new DeleteMediaOperation(menuItem.getLocalizedLabel(), EditorUtil.getUndoContext(), description, media, config, mediaView);

                     AbstractUtility.executeOperation(operation);

                 }

             }

		if (!config.isOnlyRemoveFromGallery()){

			DeleteResult result = CdmStore.getService(IMediaService.class).delete(media.getUuid(), config);

			String errorMessage = "The media ";

			if (!result.isOk()){

				List<String> messages = new ArrayList<String>();

				int i = result.getExceptions().size();

				for (Exception e:result.getExceptions()){

					messages.add(e.getMessage());

				}

				errorMessage += "could not be deleted from database. ";

				//MessagingUtils.errorDialog("test", getClass(), "message", TaxeditorBulkeditorPlugin.PLUGIN_ID, result.getExceptions().iterator().next(),true);

				DeleteResultMessagingUtils.messageDialogWithDetails(result,errorMessage, TaxeditorBulkeditorPlugin.PLUGIN_ID);

				if (config.isDeleteFromDescription()){

					ImagesUtility.removeMediaFromGallery(description, media);

				}

			}else{

				ImagesUtility.removeMediaFromGallery(description, media);

		} else{

			ImagesUtility.removeMediaFromGallery(description, media);