playItem.setImage(_playImage);
playItem.addSelectionListener(new SelectionAdapter() {
public void widgetSelected(SelectionEvent e) {
Object selection = ((IStructuredSelection) treeViewer.getSelection()).getFirstElement();
RadioItem itemToPlay = null;
if (selection instanceof CategoryRadioItem) {
itemToPlay = (RadioItem) ((CategoryRadioItem) selection).getChildren().get(0);
} else {
itemToPlay = (RadioItem) selection;
}