public void setExpanded(Object treeNode, boolean expanded) { if (_rootExpanded && treeNode == _rootTreeNode && !expanded) { return; } if (expanded) { if (_allExpanded) { _collapsedTreeNodes.removeObject(treeNode); } else { _expandedTreeNodes.addObject(treeNode); } } else { if (_allExpanded) { _collapsedTreeNodes.addObject(treeNode); } else { _expandedTreeNodes.removeObject(treeNode); } } }