JTree and dropdown options on right clicking nodes - swing

Question

I'm trying to use the JTree and implement different drop downs for all the parent nodes and the children nodes.
Here's what I've done:
pmTree.addMouseListener(new java.awt.event.MouseAdapter() {
#Override
public void mouseClicked(java.awt.event.MouseEvent evt) {
try {
if(evt.getButton() == evt.BUTTON1) {
}
else if (evt.getButton() == evt.BUTTON3) {
TreePopup(evt);
//pmTree.updateUI();
}
}catch (Exception e) {}
}
});
and PopupCode:
public void TreePopup(java.awt.event.MouseEvent evt) {
DefaultMutableTreeNode node = (DefaultMutableTreeNode) pmTree.getLastSelectedPathComponent();
popup = new JPopupMenu();
popup.setInvoker(pmTree);
PopupHandler handler = new PopupHandler(pmTree, popup);
if(node.getLevel() == 1)
{
popup.add(getMenuItem("Parent Node", handler));
}
else if(node.getLevel() == 2)
{
popup.add(getMenuItem("Child", handler));
}
}
and PopUpHandler:
public class PopupHandler extends javax.swing.JFrame implements ActionListener {
JPopupMenu popup;
Point loc;
public PopupHandler(JTree tree, JPopupMenu popup) {
//this.tree = NewJFrame.pmTree;
this.popup = popup;
tree.addMouseListener(ma);
}
and also the
public void actionPerformed(java.awt.event.ActionEvent evt)
for the Child or Parent node being clicked.
However, when I run the program, I get the SAME right click popups for both the child and parent node.
Sorry for the huge chunk of code. I've been stuck with it for 2 days and yet not successful.
Thanks!

Answer 1

Don't go as low-level as a MouseListener, instead use the api around componentPopupMenu. Doing so, the general approach is dynamically configure the componentPopup in the getPopupLocation method, some simple example snippet:
JPopupMenu popup = new JPopupMenu();
final Action action = new AbstractAction("empty") {
#Override
public void actionPerformed(ActionEvent e) {
// TODO Auto-generated method stub
}
};
popup.add(action);
JTree tree = new JTree() {
/**
* #inherited <p>
*/
#Override
public Point getPopupLocation(MouseEvent e) {
if (e != null) {
// here do your custom config, like f.i add/remove menu items based on context
// this example simply changes the action name
TreePath path = getClosestPathForLocation(e.getX(), e.getY());
action.putValue(Action.NAME, String.valueOf(path.getLastPathComponent()));
return e.getPoint();
}
action.putValue(Action.NAME, "no mouse");
return null;
}
};
tree.setComponentPopupMenu(popup);

Answer 2

You check the selected node:
DefaultMutableTreeNode node = (DefaultMutableTreeNode)pmTree.getLastSelectedPathComponent();
to see if you have a "parent" or a "child" node. You should select the node at the mouse position first, otherwise it will not be the right node. Call
TreePath path = pmTree.getPathForLocation(evt.getX(), evt.getY());
if (path != null) {
pmTree.setSelectionPath(path);
} else {
return;
}
at the beginning of treePopup. (methods in Java should start with a lower case letter!)

Answer 3

Awesome. I was successfully able to put the setSelectionPath() call inside the override of getPopupLocaiton(). I had been trying to do it inside the ActionListener of my JMenuItem to no avail.
public Point getPopupLocation( MouseEvent e ) {
Point point = null;
if( e != null ) {
TreePath path = getClosestPathForLocation( e.getX(), e.getY() );
setSelectionPath( path );
point = e.getPoint();
}
return point;
}