JTree: setting custom open / close icons for specific groups

• I know how to set custom leaf icons in JTree
• I know how to set custom private / public icons for all nodes in a group.

But I cannot set custom public / private icons based on node group names, for example a node could be called emails (so nice to have an envelope icon), or a single group could be triggered by tasks, etc.

I tried to do this by overriding the getTreeCellRendererComponent

class methodDefaultTreeCellRenderer

But changing icon

to the current one node

will only affect the next node!

How do I set custom public / private icons for specific groups?

Please take a look at my code:

Employee.java

package com.ehsunbehravesh.swing;

import java.util.Random;

public class Employee {

  public String name;
  public int id;
  public boolean isBoss;
  public Employee[] employees;

  public Employee(String name, boolean isBoss) {
    this.name = name;
    this.isBoss = isBoss;
    this.id = new Random(System.currentTimeMillis()).nextInt(Integer.MAX_VALUE);
  }  

  @Override
  public String toString() {
    return this.name;
  }

    static String randomName() {
    String chars = "abcdefghijklmnopqrstuvwxyz";
    StringBuilder builder = new StringBuilder();
    Random r = new Random(System.currentTimeMillis());
    int length = r.nextInt(10) + 1;
    for (int i = 0; i < length; i++) {
      builder.append(chars.charAt(r.nextInt(chars.length())));
    }

    return builder.toString();
  }
}

      

        
        
        
      

    

CustomTreeNode.java

package com.ehsunbehravesh.swing;

import javax.swing.ImageIcon;
import javax.swing.tree.DefaultMutableTreeNode;

public class CustomTreeNode extends DefaultMutableTreeNode {

  /**
   * The icon which is displayed on the JTree object. open, close, leaf icon.
   */
  private ImageIcon icon;

  public CustomTreeNode(ImageIcon icon) {
    this.icon = icon;
  }

  public CustomTreeNode(ImageIcon icon, Object userObject) {
    super(userObject);
    this.icon = icon;
  }

  public CustomTreeNode(ImageIcon icon, Object userObject, boolean allowsChildren) {
    super(userObject, allowsChildren);
    this.icon = icon;
  }

  public ImageIcon getIcon() {
    return icon;
  }

  public void setIcon(ImageIcon icon) {
    this.icon = icon;
  }    
}

      

        
        
        
      

    

CustomeTreeCellRenderer.java

package com.ehsunbehravesh.swing;

import java.awt.Component;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellRenderer;

class CustomeTreeCellRenderer extends DefaultTreeCellRenderer {

  public CustomeTreeCellRenderer() {
  }

  @Override
  public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
    super.getTreeCellRendererComponent(tree, value, leaf, expanded, leaf, row, hasFocus);

    if (!leaf) {
      CustomTreeNode node = (CustomTreeNode) value;
      System.out.println(((Employee) node.getUserObject()).name);

      if (node.getIcon() != null) {
        System.out.println(node.getIcon().toString());
        setClosedIcon(node.getIcon());
        setOpenIcon(node.getIcon());
      } else {
        setClosedIcon(getDefaultClosedIcon());
        setClosedIcon(getDefaultOpenIcon());
        setOpenIcon(getDefaultOpenIcon());
      }
    }

    return this;
  }
}

      

        
        
        
      

    

Test1.java

package com.ehsunbehravesh.swing;

import java.awt.BorderLayout;
import java.awt.Color;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeModel;

class TreeSample {
  public static void main(String args[]) {
    JFrame f = new JFrame("JTree Sample");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    JPanel pnlMain = new JPanel(new BorderLayout());
    pnlMain.setBackground(Color.white);

    createTree(pnlMain);

    f.setContentPane(pnlMain);

    f.setSize(300, 200);
    f.setVisible(true);
  }

  private static void createTree(JPanel pnlMain) {
    Employee bigBoss = new Employee(Employee.randomName(), true);
    Employee[] level1 = new Employee[5];    
    bigBoss.employees = level1;

    for (int i = 0; i < level1.length; i++) {
      level1[i] = new Employee(Employee.randomName(), true);      
    }


    for (int i = 0; i < level1.length; i++) {
      Employee employee = level1[i];
      if (employee.isBoss) {
        int count = 5;
        employee.employees = new Employee[count];

        for (int j = 0; j < employee.employees.length; j++) {
          employee.employees[j] = new Employee(Employee.randomName(), false);          
        }
      }
    }

    CustomTreeNode root = new CustomTreeNode(new ImageIcon("images/Circle_3.gif"), bigBoss);           
    DefaultTreeModel model = new DefaultTreeModel(root);

    for (Employee employee : bigBoss.employees) {
      CustomTreeNode boss = new CustomTreeNode(new ImageIcon("images/Circle_2.gif"), employee);
      root.add(boss);
      if (employee.isBoss) {                
        for (Employee employee1 : employee.employees) {
          CustomTreeNode emp = new CustomTreeNode(new ImageIcon("images/Circle_1.gif"), employee1);
          boss.add(emp);
        }
      }
    }

    JTree tree = new JTree(model);
    tree.setCellRenderer(new CustomeTreeCellRenderer());            
    pnlMain.add(tree, BorderLayout.CENTER);
  }  
}