Question

I want to change the cursor to hand cursor on mouse move over JTree component when the cursor is on listed elements only, not for the whole component.

The below code is for Jlist Component. I want same for the JTree, but JTree does not have getCellBound(). Is there any other way?

final JList list = new JList(new String[] {"a","b","c"});
list.addMouseMotionListener(new MouseMotionListener() {
@Override
public void mouseMoved(MouseEvent e) {
    final int x = e.getX();
    final int y = e.getY();
    // only display a hand if the cursor is over the items
    final Rectangle cellBounds = list.getCellBounds(0, list.getModel().getSize() - 1);
    if (cellBounds != null && cellBounds.contains(x, y)) {
        list.setCursor(new Cursor(Cursor.HAND_CURSOR));
    } else {
        list.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
    }
}

@Override
public void mouseDragged(MouseEvent e) {
}
});

Answer 1

You are looking for something like this, I guess:

import java.awt.Cursor;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTree;
import javax.swing.SwingUtilities;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;

public class TestTreeSelection {

    protected void initUI() {
        final DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
        fillTree(root, 5, "Some tree label");
        final DefaultTreeModel model = new DefaultTreeModel(root);
        final JTree tree = new JTree(model);
        tree.addMouseMotionListener(new MouseAdapter() {
            @Override
            public void mouseMoved(MouseEvent e) {
                boolean inside = false;
                TreePath path = tree.getPathForLocation(e.getX(), e.getY());
                if (path != null) {
                    Rectangle pathBounds = tree.getPathBounds(path);
                    inside = pathBounds.contains(e.getPoint());
                }
                if (inside) {
                    tree.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
                } else {
                    tree.setCursor(Cursor.getDefaultCursor());
                }
            }
        });
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new JScrollPane(tree));
        f.setSize(400, 600);
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }

    private void fillTree(DefaultMutableTreeNode parent, int level, String label) {
        for (int i = 0; i < 5; i++) {
            DefaultMutableTreeNode node = new DefaultMutableTreeNode(label + " " + i);
            parent.add(node);
            if (level > 0) {
                fillTree(node, level - 1, label);
            }
        }
    }

    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                new TestTreeSelection().initUI();
            }
        });
    }

}