* Adds the outline style toggle to the context menu.
*/
@Override
protected IContributionItem[] createMenuContributions(TreeViewer viewer) {
IContributionItem styleItem = new ActionContributionItem(
new OutlineStyleAction(viewer));
IContributionItem[] items = super.createMenuContributions(viewer);
if (items == null) {
items = new IContributionItem[] { styleItem };
}
else {