JTree doesn`t update after removing node

Question

I am trying to remove node from JTree and i have two codes That code is working

public class test {
private JFrame frame;
JTree tree;
DefaultMutableTreeNode root;
DefaultTreeModel model;
private Map<String, DefaultMutableTreeNode> treeMap;

public static void main(String[] args) {
    test t = new test();
    //scrolltree is basically a panel contains class has JTree
    scrolltree st = new scrolltree();
    t.frame.add(st);
    JButton b = new JButton("remove node");
    t.frame.add(b, BorderLayout.SOUTH);
    b.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            DefaultTreeModel model = (DefaultTreeModel) st.getTree().getTree().getModel();
            String key = new currentfolder().getCurrentfolder() + "/" + "a3.png";
            System.out.println(key);
            model.removeNodeFromParent(st.getTree().getTreeMap().get(key));
        }
    });
    t.frame.revalidate();
    t.frame.repaint();

}

public test() {
    frame = new JFrame();
    frame.setVisible(true);
    frame.setSize(500, 500);
}

and that code removes it perfectly and updated it too

while the other same one delete the node but doesn`t update it(unless i created new tree and replaced with old one)

i have tried all listed solution in many placed like https://community.oracle.com/thread/2495518?tstart=0

but non of them work my non-working code goes as follows

     DefaultTreeModel model = (DefaultTreeModel)startframe.getScrolltree().getTree().getTree().getModel();
     String key = new currentfolder().getCurrentfolder()+"/"+"a3.png";
     System.out.println(key);
     model.removeNodeFromParent(startframe.getScrolltree().getTree().getTreeMap().get(key));

and my class tree goes as following

public class tree {
JTree tree;
DefaultMutableTreeNode node1;
DefaultTreeModel model;
String name = new currentfolder().getInitial();// path to directory that its
                                                // content appear in tree
private Map<String, DefaultMutableTreeNode> treeMap;

public tree() {
    tree = new JTree();
    tree.setExpandsSelectedPaths(true);
    node1 = new DefaultMutableTreeNode(name);
    model = new DefaultTreeModel(node1);
    tree.setModel(model);
    treeMap = new HashMap<>();
    treeMap.put(name, node1);
    //method to inset many other nodes
    import_data(new File(name), node1);

    model.reload();
    tree.setOpaque(false);
    tree.getSelectionModel().setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);
    tree.setBorder(javax.swing.BorderFactory.createCompoundBorder(
            new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.RAISED),
            javax.swing.BorderFactory.createTitledBorder("")));
    tree.setVisible(true);

when i do tree t = new tree; then place it over old tree it works

how can I fix that and any explanation why this isn`t working? thanks

First, be sure to construct and manipulate Swing GUI objects _only_ on the [event dispatch thread](http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html). — trashgod, Jun 23 '16 at 18:25
for better help sooner post an SSCCE / MCVE, short, runnable, compilable, by using Icons from UIManager, mabye something inside model.removeNodeFromParent(startframe.getScrolltree().getTree().getTreeMap().get(key)); doens't works coorectly (meaning notifiers in JTree / treemodel ....), just guessing — mKorbel, Jun 24 '16 at 07:40
whats reasons for t.frame.revalidate(); and t.frame.repaint(); (more is explained in comment by @trashgod) — mKorbel, Jun 24 '16 at 07:41
@mKorbel its just for updating after adding new swing components,yes i better be using swing utilites,thanks for this point — Kareem Elsayed, Jun 24 '16 at 10:27
@trashgod i am already using swingutilites with the non working code — Kareem Elsayed, Jun 24 '16 at 10:29
@mKorbel i though this method is the best way to remove node as it notify all required events to update gui and jtree too ?right ? — Kareem Elsayed, Jun 24 '16 at 11:18
@trashgod I figured out the problem .i was using thread and in its runnable i created `SwingUtilites.invokeAndWait()`........when I replace all that with `SwingUtilites.InvokeLater` it worked.i dont understand why as it supposed they both do the same job except for waiting part as descriped in your link too — Kareem Elsayed, Jun 24 '16 at 16:12
post it as a solution so i can close the question. thank you. — Kareem Elsayed, Jun 24 '16 at 16:14
@KareemElsayed: Kudos for persevering; I've elaborated below. — trashgod, Jun 24 '16 at 19:25

score 3 · Accepted Answer · edited May 23 '17 at 12:33

3

When I replace all that with SwingUtilites.invokeLater(), it worked. I don't understand why.

As suggested here, be sure to construct and manipulate Swing GUI objects only on the event dispatch thread‌. In particular, updating the TreeModel from another thread means that the listening JTree view may receive updates in some unexpected order—or not at all.

edited May 23 '17 at 12:33

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answered Jun 24 '16 at 19:23

trashgod

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JTree doesn`t update after removing node

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