public void toggleExpandState(int state, StructuredSelection selection) {
TreeItem[] items = fExtensionTree.getTree().getSelection();
if (state == NEEDS_EXPAND) { // expand sub tree
traverseChildrenAndSetExpanded(items); // load non-expanded children
fExtensionTree.refresh();
expandChildrenElements(selection.toArray(), true);
fExtensionTree.setSelection(selection, false);
} else { // collapse sub tree
for (Iterator<?> iterator = selection.iterator(); iterator.hasNext(); ) {
fExtensionTree.setExpandedState(iterator.next(), false);
}
}
}
