StructuredSelection structured = (StructuredSelection) selection;
final Object element = structured.getFirstElement();
viewer.expandToLevel(element, 1);
if (element instanceof HasDoubleClickAction) {
HasDoubleClickAction hdc = (HasDoubleClickAction) element;
Action doubleClickAction = hdc.getDoubleClickAction();
if (doubleClickAction != null) {
doubleClickAction.run();
}
} else if (element instanceof Fabric) {
final Fabric fabric = (Fabric) element;