 with tree nodes using categories along with other tree nodes which does not use categories. 

Lets create a formatted tree to demonstrate this. 

\code
TreeNode* nodeA = new TreeNode("Node A");
TreeNode* nodeB = nodeA->addNode("Node B");
TreeNode* nodeC = nodeA->addNode("Node C");
nodeC->enableCategorizedDisplay();

// Add some formatting to the nodes:
nodeA->setForegroundRole(QBrush(Qt::darkRed));
nodeA->setFont(QFont("Helvetica [Cronyx]",20));
nodeA->setAlignment(Qt::AlignCenter);
nodeA->setBackgroundRol