Modify JTree nodes appearance

Question

I'm trying to visualize a JTree node as a JButton, I already tried creating a DefaultMutableTreeNode with a Jbutton object and the added it to the JTree:

JButton button = new JButton("Thing");
DefaultMutableTreeNode root = new DefaultMutableTreeNode(button);
JTree alberoClassi = new JTree(root);

These only show an error line with black parameters.
Searching the net I only found that I need a TreeRendererCell class, but none of the results show how to use it.
Are there some tutorials where I can find some examples to accomplish the task?

Something like [this](https://stackoverflow.com/questions/20691946/set-icon-to-each-node-in-jtree) — XtremeBaumer, Mar 01 '19 at 14:47

score 0 · Accepted Answer · answered Mar 03 '19 at 15:35

Finally I managed to solve the problem using an external class which implements the javax.swing.tree.TreeCellRenderer interface.

public class ClassCellRenderer implements javax.swing.tree.TreeCellRenderer {

JLabel className = new JLabel(" ");
JButton renderer = new JButton();
DefaultTreeCellRenderer defaultRenderer = new DefaultTreeCellRenderer();

public ClassCellRenderer() {
    renderer.add(className);
}

@Override
public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
    Component returnValue = null;
    if ((value != null) && (value instanceof DefaultMutableTreeNode)) {
      Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
      if (userObject instanceof String) {
          String e = (String) userObject;
          className.setText(e);
      }
      returnValue = renderer;
    }
    if (returnValue == null) {
      returnValue = defaultRenderer.getTreeCellRendererComponent(tree, value, selected, expanded,
          leaf, row, hasFocus);
    }
    return returnValue;
}
}

The JLabel and JButton could be changed with any other Component needed. To add the renderer to the Tree, I used these lines:

    alberoClassi = new JTree(root);
    TreeCellRenderer renderer = new ClassCellRenderer();
    alberoClassi.setCellRenderer(renderer); //aggiunta del renderer per i nodi

Modify JTree nodes appearance

1 Answers1