JTree color not changing in JFrame

Question

I have created a JTree for my application. Now I want to change the color of some nodes or of complete tree itself. I searched and found to create a custom TreeCellRendererComponent and update the color in it but it is not working for me. Maybe I am missing something or what I am thinking is maybe I'm updating certain property of JTree which is causing the color to not change.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Font;

import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.border.EmptyBorder;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.DefaultTreeModel;

public class TestClass2 extends JFrame {

    private JPanel contentPane;

    /**
     * Launch the application.
     */
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    TestClass2 frame = new TestClass2();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    /**
     * Create the frame.
     */
    public TestClass2() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(new BorderLayout());
        contentPane.add(prepareCommandTree(), BorderLayout.CENTER);
    }


    public static JTree prepareCommandTree()
    {
        // Root node name which is the name of the command e.g. Display Text
        DefaultMutableTreeNode commandNode = new DefaultMutableTreeNode("Command Name");
        DefaultMutableTreeNode completeData = new DefaultMutableTreeNode("Complete Data");

        // Adding all branches under root branch
        commandNode.add(completeData);

        //create the tree by passing in the root node
        JTree commandTree = new JTree(commandNode);
        DefaultTreeModel model = (DefaultTreeModel)commandTree.getModel();
        DefaultMutableTreeNode root = (DefaultMutableTreeNode)model.getRoot();
        model.reload(root);

        // Setting JTree background
        commandTree.setOpaque(false);
        commandTree.collapseRow(0);
        commandTree.setBorder(new EmptyBorder(5, 0, 0, 0));
        commandTree.setFont( new Font(Font.MONOSPACED, Font.PLAIN, 13));

        // Adding image icon to the tree
        commandTree.setCellRenderer(new DefaultTreeCellRenderer(){
        private static final long serialVersionUID = 1L;

        public Component getTreeCellRendererComponent(final JTree tree,Object value,
          boolean sel,boolean expanded,boolean leaf,int row,boolean hasFocus)
        {
            // Trying to change color of tree
            setForeground(Color.RED);
            JLabel label = (JLabel)super.getTreeCellRendererComponent(tree,value,
                                                  sel,expanded,leaf,row,hasFocus);
                return label;
        }
        });

        // Setting adjustments to JTree properties
        commandTree.putClientProperty("JTree.lineStyle", "None");
        commandTree.setAlignmentX(Component.LEFT_ALIGNMENT);
        DefaultTreeCellRenderer renderer = (DefaultTreeCellRenderer) commandTree.getCellRenderer();
        renderer.setLeafIcon(null);
        renderer.setClosedIcon(null);
        renderer.setOpenIcon(null);

        return commandTree;
    }
}

Any suggestion/correction will be helpful. Thanks. :-)

Answer 1

Your renderer sets its foreground Color before the super call has been performed.

The super method also sets a foreground Color, which will replace the one you have set.

Just apply the Color after the super call .

    public Component getTreeCellRendererComponent(final JTree tree, final Object value,
            final boolean sel, final boolean expanded, final boolean leaf, final int row,
            final boolean hasFocus) {
        // Trying to change color of tree

        JLabel label = (JLabel) super.getTreeCellRendererComponent(tree, value,
                sel, expanded, leaf, row, hasFocus);
        setForeground(Color.RED);
        return label;// Or "return this", since the method actually returns the renderer component itself
    }
});