@Override public boolean contributesTo(GraphContainer container) { T ref = findSingleSelectedItem(container); if (ref != null) { return contributesTo(ref, container); } return false; }
@Override public Component getComponent(GraphContainer container) { T ref = findSingleSelectedItem(container); Preconditions.checkState(ref != null, NOTHING_SELECTED); return getComponent(ref, container); }
@Override public String getTitle(GraphContainer container) { T ref = findSingleSelectedItem(container); Preconditions.checkState(ref != null, NOTHING_SELECTED); return getTitle(ref); }