How to disabled a node.

[smartsubroto]

Hi All,

I am trying to disabled one node using following code:

child = new DefaultMutableTreeNode("Inventory");
parent.add(child);

child.setEnabled(false);

but when i am compiling it i am getting the following error:

Navigate1.java:348: cannot find symbol
symbol : method setEnabled(boolean)
location: class javax.swing.tree.DefaultMutableTreeNode
child.setEnabled(false);


Please Help...

Thanks in advance...:

[Eranga]

Can you show your code. Hard to tell anything looking at the code.

[smartsubroto]

child = new DefaultMutableTreeNode("Inventory");
parent.add(child);

child.setEnabled(false);

model = new DefaultTreeModel(parent);
tree = new JTree(model);
tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
linksRenderer = new DefaultTreeCellRenderer();
linksRenderer.setBackgroundNonSelectionColor(Color .lightGray);
linksRenderer.setBackgroundSelectionColor(Color.WH ITE);
tree.setCellRenderer(linksRenderer);
JScrollPane treeView = new JScrollPane(tree);
treeView.setPreferredSize(new Dimension(250, 350));

panel.add(treeView);
treeView.setBounds(10,40,300,430);
tree.setBackground(Color.lightGray);


in the above code

"Parent" is the root node and the "Child" is leaf of that node in a JTree.

and i want to disable the leaf node..

Plz suggest something

[Eranga]

I think you can try something like this. On a click of the leaf get the leaf name. Compare it with the name of the leaf you want to disable. If it's true make setEnable(false)

You have try something like this at the start of code.

child.setEnabled(false);

What happened there, did you debug and see it?

[Niveditha]

Generally we get "cannot find symbol" error to such java classes when the imports for it are not present, please do check that once.

Or another probable reason would be because u r making it disabled before adding it to the tree. Try first adding it to the mutabletree and then making it disabled at the end.(i am not sure of it, its just my guess)

[Eranga]

Yep, that's why I'm worried about the mentioned line of code. Just after declaring set to disable.

[Niveditha]

Hi,
Can u(person who initiated this thread) post the whole code from end to end instead of a part of it.

Before thay try the given suggestion,that may solve ur problem

[Eranga]

That's the best thing if you grab the correct issue from the code. In shorter period you can have the solution.

[smartsubroto]

i use the following code:

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreeSelectionModel;

import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.event.TreeSelectionListener;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.tree.TreeSelectionModel;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.ImageIcon;
import java.net.URL;
import java.io.IOException;
import javax.swing.JEditorPane;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;

public class TreeDemo
{
JFrame f1;
JPanel p1;
static JTree tree;
DefaultTreeModel model;
DefaultTreeCellRenderer linksRenderer;
DefaultMutableTreeNode parent,child1,child2;
public TreeDemo()
{
f1=new JFrame("Tree Demo");
p1=new JPanel();
f1.getContentPane().add(p1);

parent = new DefaultMutableTreeNode("Parent");

child1 = new DefaultMutableTreeNode("Child1");
parent.add(child1);

child2 = new DefaultMutableTreeNode("Child2");
parent.add(child2);

child2.setEnabled(false);

model = new DefaultTreeModel(parent);
tree = new JTree(model);
tree.getSelectionModel().setSelectionMode(
TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
linksRenderer = new DefaultTreeCellRenderer();
linksRenderer.setBackgroundNonSelectionColor(Color .lightGray);
linksRenderer.setBackgroundSelectionColor(Color.WH ITE);
tree.setCellRenderer(linksRenderer);
JScrollPane treeView = new JScrollPane(tree);
treeView.setPreferredSize(new Dimension(250, 350));

p1.add(treeView);
treeView.setBounds(10,40,300,430);
tree.setBackground(Color.lightGray);

f1.setSize(400,400);
f1.show();
}
public static void main(String args[])
{
new TreeDemo();
}
}


and the error..

D:>javac treedemo.java
treedemo.java:43: cannot find symbol
symbol : method setEnabled(boolean)
location: class javax.swing.tree.DefaultMutableTreeNode
child2.setEnabled(false);
^
Note: treedemo.java uses or overrides a deprecated API.
Note: Recompile with -Xlint:deprecation for details.
1 error


Plz... Suggest..

[Eranga]

Do you want to block all childes of a leaf, right?

[smartsubroto]

No i just want to block one child leaf.

and also if we can block any one child then there will no problem in blocking of whole node..

[Eranga]

So why don't you try to set setAllowsChildren() false on the specific child node.

[smartsubroto]

setAllowsChildren(boolean) is used to set, wheather the node is able to have children or not.

This command is not disabling the leaf..

I use this code as:

child2.setAllowsChildren(false);

but it does nothing in this case..

[Niveditha]

Hi,
Check this link, it has something similar like what u want.

How to disable a certain treenode in a jtree (Swing / AWT / SWT / JFace forum at JavaRanch)

[Eranga]

setAllowsChildren(boolean) is used to set, wheather the node is able to have children or not.

This command is not disabling the leaf..

I use this code as:

child2.setAllowsChildren(false);

but it does nothing in this case..

If I got you correctly this is what you want to do, right?

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.tree.*;

public class TreeDemo {

    JFrame f1;
    JPanel p1;
    static JTree tree;
    DefaultTreeModel model;
    DefaultTreeCellRenderer linksRenderer;
    DefaultMutableTreeNode parent,child1,child2, child3;

    public TreeDemo() {
        f1 = new JFrame("Tree Demo");
        p1 = new JPanel();
        f1.getContentPane().add(p1);

        parent = new DefaultMutableTreeNode("Parent");
        child1 = new DefaultMutableTreeNode("Child1");
        parent.add(child1);

        child2 = new DefaultMutableTreeNode("Child2");
        parent.add(child2);

        child3 = new DefaultMutableTreeNode("child3");
        child2.add(child3);

        model = new DefaultTreeModel(parent);
        tree = new JTree(model);
        tree.getSelectionModel().setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
        linksRenderer = new DefaultTreeCellRenderer();
        linksRenderer.setBackgroundNonSelectionColor(Color .lightGray);
        //linksRenderer.setBackgroundSelectionColor(Color.WH ITE);
        tree.setCellRenderer(linksRenderer);
        JScrollPane treeView = new JScrollPane(tree);
        treeView.setPreferredSize(new Dimension(250, 350));

        child2.setAllowsChildren(false); // Try changing the status 
        
        p1.add(treeView);
        treeView.setBounds(10,40,300,430);
        tree.setBackground(Color.lightGray);

        f1.setSize(400,400);
        f1.show();
    }

    public static void main(String args[]) {
        new TreeDemo();
    }
}

[smartsubroto]

here
chil2.setAllowsChildren(false);

is not useful to disable a leaf.

[Eranga]

That mean I'm still not get what you exactly wants.

[smartsubroto]

I just want to disable that particular leaf.

for EX:
if there is buttton say..
JButton b1=new JButton("I Am Disable");
b1.setEnabled(false);

in the above case button is there but it is disabled.
I just want to implement the same thing in leaf.

[Niveditha]

Hi,
did u check the link i provided before?

[Eranga]

I just want to disable that particular leaf.

for EX:
if there is buttton say..
JButton b1=new JButton("I Am Disable");
b1.setEnabled(false);

in the above case button is there but it is disabled.
I just want to implement the same thing in leaf.

Ok, in that sense disable a leaf is, it's there and you can't workout with it's child, isn't it?