{
Object obj = ( ( IStructuredSelection ) event.getSelection() ).getFirstElement();
if ( treeViewer.getExpandedState( obj ) )
treeViewer.collapseToLevel( obj, 1 );
else if ( ( ( ITreeContentProvider ) treeViewer.getContentProvider() ).hasChildren( obj ) )
treeViewer.expandToLevel( obj, 1 );
}
}
} );
this.refresh();