Necesito usar un renderizador de celdas personalizado para mi JTree para agregar algo de JLabel en cada celda. Y luego permita que el usuario haga clic en estas etiquetas sin necesidad de seleccionar primero la celda.

Entonces, he creado un Renderer que devuelve un JPanel que contiene un DefaultTreeCellRenderer y 2 JLabel.

    public class TreeNodeRenderer extends DefaultTreeCellRenderer implements TreeCellRenderer
    {
        private JPanel panel1 = new JPanel();
        private JLabel delete = new JLabel("");
        private JLabel upload = new JLabel("");

        public Component getTreeCellRendererComponent(JTree tree, 
                            Object value,
                boolean selected, boolean expanded, boolean leaf, int row,
                boolean hasFocus) 
        {   
            //
            // DELETE label
            //
            delete.setName("delete");
            delete.setIcon(new ImageIcon("Data/trash.png"));

            //
            // UPLOAD label
            //
            upload.setName("upload");
            upload.setIcon(new ImageIcon("Data/app_up.png"));


            DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();
            Color backgroundSelectionColor = defaultRenderer.getBackgroundSelectionColor();
            Color backgroundNonSelectionColor = defaultRenderer.getBackgroundNonSelectionColor();

            if(selected)
                panel1.setBackground(backgroundSelectionColor);
            else
                panel1.setBackground(backgroundNonSelectionColor);


            component = (DefaultTreeCellRenderer) super.getTreeCellRendererComponent(tree,
                    value, selected, expanded, leaf, row, hasFocus);

            panel1.add(component);
            panel1.add(delete);
            panel1.add(upload);

            return panel1;
        }
    }

Entonces he creado el editor para permitir al usuario hacer clic en estas etiquetas gracias a MouseListener. Todo funciona bien, excepto que el usuario debe seleccionar la celda antes de hacer clic en una etiqueta. Traté de devolver "false" con el método "ShouldSelectCell" pero no funciona.

¿Alguien sabe por qué?

Aquí el editor:

public class TreeNodeEditor extends AbstractCellEditor implements TreeCellEditor
{
    private TreeNodeRenderer renderer;

    public TreeNodeEditor(TreeNodeRenderer treeRenderer)
    {
        this.renderer = treeRenderer;

    //change the cursor when it's over a label  renderer.getDeleteButton().setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
    renderer.getUploadButton().setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));       renderer.getDownloadButton().setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));

                 //add labels' mouse listeners 
        addLabelMouseListener(renderer.getDeleteButton());
        addLabelMouseListener(renderer.getUploadButton());
    }

    public Component getTreeCellEditorComponent(JTree tree, Object value, boolean isSelected, boolean expanded, boolean leaf, int row)
    {
        ...

        return renderer.getTreeCellRendererComponent(
                tree, value, isSelected,
                expanded, leaf, row, true);
    }

    public boolean isCellEditable(EventObject anEvent) 
    {
        return true;
    }

    public boolean shouldSelectCell(EventObject anEvent) 
    {
        return false;
    }


    public boolean stopCellEditing() 
    {
        return super.stopCellEditing();
    }

    public void cancelCellEditing() 
    {
        super.cancelCellEditing();
    }

    public void addCellEditorListener(CellEditorListener l)
    {
        super.addCellEditorListener(l);
    }

    public void removeCellEditorListener(CellEditorListener l) 
    {
        super.removeCellEditorListener(l);
    }

    public Object getCellEditorValue() 
    {
        return null;
    }
}

EDIT - Aquí un SSCCE:

import java.awt.Color;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.EventObject;

import javax.swing.AbstractCellEditor;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.CellEditorListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeCellEditor;
import javax.swing.tree.TreeCellRenderer;



public class EditJTreeCell extends JFrame
{
    /**
     * 
     */
    private static final long serialVersionUID = 4745146614430249610L;

    private JTree tree;
    private DefaultTreeModel treeModel;
    private DefaultMutableTreeNode root;

    public EditJTreeCell()
    {
        super("Sample");
        root = new DefaultMutableTreeNode("Root folder");
        treeModel = new DefaultTreeModel(root);
        tree = new JTree(treeModel);

        TreeNodeRenderer renderer = new TreeNodeRenderer();
        tree.setCellRenderer(renderer);
        tree.setCellEditor(new TreeNodeEditor());
        tree.setEditable(true);

        //tree creation
        DefaultMutableTreeNode folder = new DefaultMutableTreeNode("folder1");
        DefaultMutableTreeNode file = new DefaultMutableTreeNode("file1");
        folder.add(file);
        file = new DefaultMutableTreeNode("file2");
        folder.add(file);
        root.add(folder);
        folder = new DefaultMutableTreeNode("folder2");
        file = new DefaultMutableTreeNode("file1");
        folder.add(file);
        file = new DefaultMutableTreeNode("file2");
        folder.add(file);
        file = new DefaultMutableTreeNode("file3");
        folder.add(file);
        root.add(folder);

        this.setSize(400, 800);
        this.add(tree);
        this.setVisible(true);
    }

    public static void main(String[] args) 
    {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel");
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (UnsupportedLookAndFeelException e) {
            e.printStackTrace();
        }
        new EditJTreeCell();
    }
}

class TreeNodeRenderer extends DefaultTreeCellRenderer implements TreeCellRenderer
{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private JPanel panel1 = new JPanel();
    private JLabel delete = new JLabel("DELETE");
    private JLabel upload = new JLabel("UPLOAD");

    public Component getTreeCellRendererComponent(JTree tree, Object value,
            boolean selected, boolean expanded, boolean leaf, int row,
            boolean hasFocus) 
    {   
        //
        // DELETE label
        //
        delete.setName("delete");
        delete.setIcon(new ImageIcon("trash.png"));
        //addLabelMouseListener(delete);
        //
        // UPLOAD label
        //
        upload.setName("upload");
        upload.setIcon(new ImageIcon("app_up.png"));
        //addLabelMouseListener(upload);


        DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();
        Color backgroundSelectionColor = defaultRenderer.getBackgroundSelectionColor();
        Color backgroundNonSelectionColor = defaultRenderer.getBackgroundNonSelectionColor();

        DefaultTreeCellRenderer component = (DefaultTreeCellRenderer) super.getTreeCellRendererComponent(tree,
                value, selected, expanded, leaf, row, hasFocus);

        if(selected)
        {   
            panel1.setBackground(backgroundSelectionColor);
        }
        else
        {
            panel1.setBackground(backgroundNonSelectionColor);
        }

        panel1.add(component);
        panel1.add(delete);
        panel1.add(upload);

        return panel1;
    }
}

class TreeNodeEditor extends AbstractCellEditor implements TreeCellEditor
{
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private JLabel button1;
    private JLabel button2;
    private JPanel panel1;
    private DefaultMutableTreeNode node = null;
    private DefaultTreeCellRenderer defaultRenderer;


    public TreeNodeEditor()
    {
        super();
        panel1 = new JPanel();
        defaultRenderer = new DefaultTreeCellRenderer();
        button1 = new JLabel("DELETE");
        button1.setOpaque(true);
        button1.setIcon(new ImageIcon("trash.png"));
        button1.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
        button1.addMouseListener(new MouseListener() 
        {
            public void mouseClicked(MouseEvent arg0) {
                System.out.println("Delete clicked");
            }
            public void mouseEntered(MouseEvent arg0) {}
            public void mouseExited(MouseEvent arg0) {}
            public void mousePressed(MouseEvent arg0) {}
            public void mouseReleased(MouseEvent arg0) {}

        });
        button2 = new JLabel("UPLOAD");
        button2.setOpaque(true);
        button2.setIcon(new ImageIcon("app_up.png"));
        button2.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
        button2.addMouseListener(new MouseListener() 
        {
            public void mouseClicked(MouseEvent arg0) {
                System.out.println("Upload clicked");
            }
            public void mouseEntered(MouseEvent arg0) {}
            public void mouseExited(MouseEvent arg0) {}
            public void mousePressed(MouseEvent arg0) {}
            public void mouseReleased(MouseEvent arg0) {}

        });
    }


    public Component getTreeCellEditorComponent(JTree tree, Object value, 
            boolean isSelected, boolean expanded, boolean leaf, int row)
    {
        //in order to do some actions on a node
        if(value instanceof DefaultMutableTreeNode)
        {
            node = (DefaultMutableTreeNode) value;
        }


         defaultRenderer.getTreeCellRendererComponent(tree,
                    value, isSelected, expanded, leaf, row, true);

        panel1.add(defaultRenderer);
        panel1.add(button1);
        panel1.add(button2);
        return panel1;
    }

    public boolean isCellEditable(EventObject anEvent) 
    {
        return true;
    }

    public boolean shouldSelectCell(EventObject anEvent) 
    {
        return false;
    }


    public boolean stopCellEditing() 
    {
        return super.stopCellEditing();
    }

    public void cancelCellEditing() 
    {
        super.cancelCellEditing();
    }

    public void addCellEditorListener(CellEditorListener l)
    {
        super.addCellEditorListener(l);
    }

    public void removeCellEditorListener(CellEditorListener l) 
    {
        super.removeCellEditorListener(l);
    }

    public Object getCellEditorValue() 
    {
        return null;
    }
}