Selection Tree Java,JTree Multiple Selection,Enabling and Disabling Multiple Selections in a Tree Component

In this section, you will learn how to enable and disable the multiple selections in a JTree component. The multiple selections in tree component that means user will allow or disallow the permission for selection the more than one tree component at a time. By default, the tree allows the multiple selections.

The following program helps you in enabling and disabling the multiple selections in a JTree component. First of all, this program constructs a simple tree that contains the root and child of root node. After creating a tree, you will allow the selection component of tree. If you want to select only one node at a time, you will use the SINGLE_TREE_SELECTION, if you will provide the selection to one vertical contiguous set of visible nodes, you will use the CONTIGUOUS_TREE_SELECTION and if you will allow the permission for multiple selection of visible nodes, you will use the DISCONTIGUOUS_TREE_SELECTION. This tree are displayed on the java swing frame.

getSelectionModel():
This is the method that returns the current selection model.

setSelectionMode():
This is the method that returns the value of selectionMode property either single-item or multiple-item.

TreeSelectionModel:
This is an interface that represents the current state of selection to the tree component. The TreeSledtionModel allows the selection only one path at a time by using the SINGLE_TREE_SELECTION, a number of contiguous paths to use the CONTIGUOUS_TREE_SELECTION or a number of discontiguous paths to use the DISCONTIGUOUS_TREE_SELECTION.

SINGLE_TREE_SELECTION:
It allows the permission for selecting only one path at a time.

CONTIGUOUS_TREE_SELECTION:
It allows the permission for selection to contiguous.

DISCONTIGUOUS_TREE_SELECTION:
It allows the selection that contains any number of items but can not be necessary contiguous.


import javax.swing.*;

import javax.swing.tree.*;



public class SelectionTree{

  public static void main(String[] args) {

    JFrame frame = new JFrame("Enabling and Disabling Multiple Selections in a 

   JTree Component!");

    DefaultMutableTreeNode myComputer = new DefaultMutableTreeNode("My Computer");

    DefaultMutableTreeNode c = new DefaultMutableTreeNode("Local Disk(C:)");

    DefaultMutableTreeNode vinod = new DefaultMutableTreeNode("Vinod");

    DefaultMutableTreeNode swing = new DefaultMutableTreeNode("Swing");

    DefaultMutableTreeNode tr = new DefaultMutableTreeNode("Tree");

    DefaultMutableTreeNode a = new DefaultMutableTreeNode("3� Floppy(A:)");

    DefaultMutableTreeNode e = new DefaultMutableTreeNode("New Volume(E:)");

    c.add(vinod);

    vinod.add(swing);

    swing.add(tr);

    myComputer.add(c);

    myComputer.add(a);

    myComputer.add(e);

    JTree tree = new JTree(myComputer);

//    Single selection node at a time

//    tree.getSelectionModel().setSelectionMode(TreeSelectionModel.

    SINGLE_TREE_SELECTION);

//    provide selection to one vertical contiguous set of visible nodes

    tree.getSelectionModel().setSelectionMode(TreeSelectionModel.

 CONTIGUOUS_TREE_SELECTION);

//    multiple selection of visible nodes

//    tree.getSelectionModel().setSelectionMode(TreeSelectionModel.

  DISCONTIGUOUS_TREE_SELECTION);

    frame.add(tree);

    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    frame.setUndecorated(true);

    frame.getRootPane().setWindowDecorationStyle(JRootPane.PLAIN_DIALOG);

    frame.setSize(200,200);

    frame.setVisible(true);

  }

}

Enable and Disable Multiple Selections in a JTree Component