Override JTree.setExpandedState() to prevent Expansion or Collapse of a Node in a JTree in Java

  //  w  w w .  ja v a2s. c  om


import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.tree.TreePath;

public class Main {
  public static void main(String[] argv) {

    JTree tree = new JTree() {
      protected void setExpandedState(TreePath path, boolean state) {
        
        if (state) {
          super.setExpandedState(path, state);
        }
      }
    };

    JFrame frame = new JFrame("Ignore all collapse requests");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.add(new JScrollPane(tree));
    frame.setSize(380, 320);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);

  }
}