Horizontal Line JTree,Line Break Between Group Nodes,Adding Horizontal Lines to Group Nodes in JTree

Adding Horizontal lines to Group Nodes

Introduction

In this section, you will learn to create a horizontal tree in java.

Description of the Program:

This program creates a JTree that contains a root and the nodes.This program implements a class (JTreeHorizontal). Here the init() method creates root and the child nodes through DefaultMutableTreeNode method. These objects are added in the JTree and the putClintProperty() method displays them horizontally in a JTree on the frame.

putclientProperty(Object key, Object val): The clientProperty dictionary is not intended to support large scale extensions to Jcomponent nor should it be considered an alternative to subclassing when designing a new component. It takes following type values:

key: This is the client property key.
val: This is the client property value.

Here is the code of this program:


import javax.swing.*;

import javax.swing.tree.*;

import java.awt.*;



public class JTreeHorizontal extends JFrame{

  JTree tree;

  public JTreeHorizontal(){

    super("JTreeHorizontal Frame");

    setSize(300, 300);

    setDefaultCloseOperation(EXIT_ON_CLOSE);

  }



  public void init(){

    DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");

    DefaultMutableTreeNode book = new DefaultMutableTreeNode("Book");

    DefaultMutableTreeNode javabook = new DefaultMutableTreeNode("Java Book"); 

    DefaultMutableTreeNode jspbook = new DefaultMutableTreeNode("JSP Book"); 

    DefaultMutableTreeNode phpbook = new DefaultMutableTreeNode("PHP Book"); 

    DefaultMutableTreeNode structbook = new DefaultMutableTreeNode("STRUCT Book"); 

    DefaultMutableTreeNode contry = new DefaultMutableTreeNode("CONTRY");

    DefaultMutableTreeNode india = new DefaultMutableTreeNode("INDIA");

    DefaultMutableTreeNode usa = new DefaultMutableTreeNode("USA");

    DefaultTreeModel treeModel = new DefaultTreeModel(root);

    tree = new JTree(treeModel);

    tree.putClientProperty("JTree.lineStyle", "Horizontal");

    treeModel.insertNodeInto(book,root, 0);

    treeModel.insertNodeInto(contry,root, 0);

    book.add(javabook);

    book.add(jspbook);

    book.add(phpbook);

    book.add(structbook);

    contry.add(india);

    contry.add(usa);

    getContentPane().add(tree, BorderLayout.CENTER);

  }



  public static void main(String args[]){



    JTreeHorizontal jh = new JTreeHorizontal();

    jh.init();

    jh.setVisible(true);

  }

}

Output this program: