TreeView nodes names bugging

Question

I'm having a lot of trouble dealing with TreeView, more specificcaly with the text shown per node.

Starting with an initializer for the Tree, where I expected a single node with the text, it might make the program more intuitive for the users:

private void defineEmpityTree(){            
    cbt.setModel(new DefaultTreeModel(
        new DefaultMutableTreeNode("Relat\u00F3rios Individuais") {
            {
            }
        }
    ));
}

and I add initialize the Tree:

cbt = new JCheckBoxTree();
    defineEmpityTree();
    scrollPane.setViewportView(cbt);

"Relatórios Individuais" aren't shown, Tree Ok, another bug

I ignored this problem and continued with the actual filling of the nodes, the user specifies his search and press "ok", thats when we get the Tree filled, 2nd image.

But then then another strange problem comes, if "ok" is pressed again, some texts go strange, 3rd image.

Heres the part of the cade where the nodes are created. For an array of files nodes are created for each type of report and each report lot, its not really important.

private void defineNewTree(ArrayList<File> files){
    DefaultMutableTreeNode dmtRoot = new DefaultMutableTreeNode("Relat\u00F3rios Individuais");
    DefaultMutableTreeNode dmtSubFolder = null;
    DefaultMutableTreeNode dmtLotFolder = null;
    int childsRoot = 0;
    int childsSub = 0;

    for(File f : files){
        String subFolder = f.getName().substring(17,f.getName().length()-4);
        String name = f.getName();
        String lot = f.getName().substring(0, 3);
        childsRoot = dmtRoot.getChildCount();
        boolean subFoldExists = false;
        boolean foldLotExists = false;
        //creatingo folder reports:
        for(int i = 0;i<childsRoot;i++){
            if(dmtRoot.getChildAt(i).toString().equals(subFolder)){
                dmtSubFolder = (DefaultMutableTreeNode) dmtRoot.getChildAt(i);          
                subFoldExists = true;
                i=childsRoot;
            }
        }
        if(!subFoldExists){ 
            dmtSubFolder = new DefaultMutableTreeNode(subFolder);
            dmtRoot.add(dmtSubFolder);
        }
        for(int j = 0;j<childsSub;j++){
            if(dmtSubFolder.getChildAt(j).toString().equals(lot)){
                dmtLotFolder = (DefaultMutableTreeNode) dmtSubFolder.getChildAt(j);
                foldLotExists = true;
                j=childsSub;
            }
        }
        if(!foldLotExists){
            dmtLotFolder = new DefaultMutableTreeNode("lote "+lot);
            dmtSubFolder.add(dmtLotFolder);
        }
        dmtLotFolder.add(new DefaultMutableTreeNode(name));

    }
    DefaultTreeModel myTree = new DefaultTreeModel(dmtRoot);

    cbt.setModel(myTree);
}

I think the real problem is that:

cbt.setModel(myTree);

Is that the correct way to define the Tree contents?

Edit.: Button OK:

...
JButton btnOk = new JButton("OK");
btnOk.setBounds(161, 37, 49, 23);
btnOk.setActionCommand("ok");
btnOk.addActionListener(buttonListener);
panel.add(btnOk);
...

class ButtonListener implements ActionListener{
    @Override
    public void actionPerformed(ActionEvent a) {
        switch(a.getActionCommand()){
            case "ok":                  
                search();
                self.requestFocusInWindow();
                break;
            case "cancel":
                dispose();
                break;
            case "print":
                TreePath[] tp = cbt.getCheckedPaths();
                for(TreePath t : tp){
                    System.out.println(t.getLastPathComponent().toString());
                }
                self.requestFocusInWindow();
                break;
            default:
                break;
        }
    }
}

private void search(){
    FileSeeker fs = new FileSeeker(textField.getText());
    ArrayList<File> files = fs.getFiles();

    defineNewTree(files);
}

Edit.: CheckBoxCellRenderer:

private class CheckBoxCellRenderer extends JPanel implements TreeCellRenderer {     
    private static final long serialVersionUID = -7341833835878991719L;     
    JCheckBox checkBox;     
    public CheckBoxCellRenderer() {
        super();
        this.setLayout(new BorderLayout());
        checkBox = new JCheckBox();
        add(checkBox, BorderLayout.CENTER);
        setOpaque(false);
    }

    @Override
    public Component getTreeCellRendererComponent(JTree tree, Object value,
            boolean selected, boolean expanded, boolean leaf, int row,
            boolean hasFocus) {
        DefaultMutableTreeNode node = (DefaultMutableTreeNode)value;
        Object obj = node.getUserObject();          
        TreePath tp = new TreePath(node.getPath());
        CheckedNode cn = nodesCheckingState.get(tp);
        if (cn == null) {
            return this;
        }
        checkBox.setSelected(cn.isSelected);
        checkBox.setText(obj.toString());
        checkBox.setOpaque(cn.isSelected && cn.hasChildren && ! cn.allChildrenSelected);
        return this;
    }       
}

Answer 1

So, for the first problem the solution is:

private void defineEmpityTree(){            
    DefaultMutableTreeNode dmtn = new DefaultMutableTreeNode("Relat\u00F3rios Individuais");
    cbt.setModel(new DefaultTreeModel(dmtn));   
    ((DefaultTreeModel) cbt.getModel()).nodeChanged(dmtn);
}

I simply had to notify that the node had changed.

For the truncation problem,

cbt.setLargeModel(true);

did the trick.