public JComponent getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded,
boolean leaf, int row, boolean hasFocus) {
JComponent c = super.getTreeCellRendererComponent(tree, value, sel, expanded, leaf, row, hasFocus);
boolean enabled = true;
if (value instanceof KongaTreeNode) {
KongaTreeNode node = (KongaTreeNode) value;
Object nodeObject = node.getUserObject();
if (nodeObject instanceof Schedule) {
enabled = checkEnabledState(node, (Schedule) nodeObject);
} else if (nodeObject instanceof Operation) {
enabled = checkEnabledState(node, (Operation) nodeObject);
}