Select Node by default

Question

I know there are a lot of similar questions to be found on Google, but I just seem to not be able to make it work somehow:

I have a JTree (called Project) and this tree has different Nodes (Folder or Table). I can add Folders and Tables to the JTree and they display after reloading the model. Now what I want to do is, once I have added a new Folder or Table to the Tree this one should be selected and expanded, but I cant get it to work.

I will try to just pick the important pieces of the code:

public void openProject() {

    final JFileChooser select = new JFileChooser();
    FileNameExtensionFilter filter = new FileNameExtensionFilter(
            "Project Files (.prj)", "prj");
    select.addChoosableFileFilter(filter);

    int returnVal = select.showOpenDialog(null);
    String path = select.getSelectedFile().getPath();
    String extention = path.substring(path.length() - 4);

    if (returnVal == JFileChooser.APPROVE_OPTION
            && extention.equalsIgnoreCase(".prj")) {

        try {
            XMLDecoder d = new XMLDecoder(new BufferedInputStream(
                    new FileInputStream(path)));
            setModel((TreeModel) d.readObject());
            d.close();
            // restore status
            List<TreeNode[]> expanded = (List<TreeNode[]>) d.readObject();
            for (int i = expanded.size() - 1; i > -1; i--) {
                TreeNode[] ar = expanded.get(i);
                expandPath(new TreePath(ar));
            }
            projectPath = path;
        } catch (FileNotFoundException ex) {
        }
        setRootVisible(true);
        reloadTree();
        root = (DefaultMutableTreeNode) getModel().getRoot();
    }
}

This piece will open up an existing Project (similar function for a new Project), define the root, set the model and reloads the tree.

If I now try:

public void addTable(){
    Table table = new Table();
    table.setUserObject("Table1");
    try{
        DefaultMutableTreeNode last = (DefaultMutableTreeNode) getLastSelectedPathComponent();
        last.add(table);        
    }catch(Exception e){
        root.add(table);
    }
    TreePath path = new TreePath(table.getPath());
    setSelectionPath(path);
    expandPath(path);
    reloadTree();
}

public void addFolder(){
    Folder folder = new Folder();
    folder.setUserObject("Folder1");
    try{
        DefaultMutableTreeNode last = (DefaultMutableTreeNode) getLastSelectedPathComponent();
        last.add(folder);

    }catch(Exception e){
        root.add(folder);
    }
    TreePath path = new TreePath(folder.getPath());
    setSelectionPath(path);
    expandPath(path);
    reloadTree();
}

It will add the node, but does not expand the path or select the newly created node. If I manually select the node, I can use this as the parent with the getLastSelectedPathComponent.

Where did I get the concept wrong? I guess I do have a pretty simple mistake in there, but I am struggling here.

*"Will do next time"* Will look into your question next time. Note that questions can be edited. — Andrew Thompson, Nov 29 '12 at 07:43

score 2 · Answer 1 · edited May 23 '17 at 12:21

2

I guess you might want to see a similar question posted here before:

Java: How to programmatically select and expand multiple nodes in a JTree?

See this and tell me if it helps :)

edited May 23 '17 at 12:21

Community

1
1

answered Nov 28 '12 at 09:15

Hazem Elraffiee

453
7
16

I saw that earlier as well, but I cant figure out how to exactly use it. – user1827421 Nov 29 '12 at 01:23
1

Okay, found something else that I was able to fit to my code. Lot of rewriting, but now it works: http://wiki.byte-welt.net/wiki/JTree_Zustand_speichern – user1827421 Nov 29 '12 at 05:36

Select Node by default

1 Answers1