JTree.isExpanded(0) - true, but jTree.collapseRow(0) - doesn't work

Question

<code>
if (jTree.isExpanded(0) ) {
System.out.println("Expanded!")
} else {
System.out.println("Collapsed!")
</code>
It says. Expanded!
So,
<code>
if (jTree.isExpanded(0) ) {
System.out.println("Expanded!")
jTree.collapseRow(0);
jTree.repaint();
} else {
System.out.println("Collapsed!")
</code>
But it doesn't work! Why?

Answer 1

If you want to control the icon that's rendered at each node you should write your own TreeCellRenderer.
How you determine which icon to show is dependent on your application. What are you putting into the tree nodes that lets you decide which icon to show?
You'd code it something along these lines:
public class MyTreeCellRenderer extends DefaultTreeCellRenderer {
     public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean focus) {
     JLabel renderer = (JLabel) super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, focus);
     Object userObject = ((DefaultMutableTreeNode) value).getUserObject();
     // TODO: change these based on the node's user object
     renderer.setText(...);
     renderer.setIcon(...);
     return renderer;
}Read up about cell renderers in the Swing Tutorial for more information.
Incidentally, if you use this approach you shouldn't need to customise the root node as indicated in another post since the user object of the root node will help you choose the icon for it.
Hope this helps.