Java Utililty Methods JTree Expand

List of utility methods to do JTree Expand

  1. HOME
  2. Java
  3. J
  4. JTree Expand

Description

The list of methods to do JTree Expand are organized into topic(s).

Method

voidexpandPath(JTree tree, TreePath tp)
expand Path 
Object root = tree.getModel().getRoot();
expandPath(tree, new TreePath(root), tp, 0);
voidexpandPathOnEdt(final JTree tree, final TreePath path)
expand Path On Edt 
SwingUtilities.invokeLater(new Runnable() {
    public void run() {
        tree.expandPath(path);
});
voidexpandPaths(JTree tree, Collection paths)
expand Paths 
if (paths != null) {
    for (Iterator<TreePath> it = paths.iterator(); it.hasNext();) {
        TreePath tp = it.next();
        expandPath(tree, tp);
voidexpandTree(JTree tree, boolean expand)
expand Tree 
TreeNode root = (TreeNode) tree.getModel().getRoot();
expandAll(tree, new TreePath(root), expand);
voidexpandTree(JTree tree, TreeNode start, int level)
expand Tree 
for (Enumeration children = start.children(); children.hasMoreElements();) {
    DefaultMutableTreeNode dtm = (DefaultMutableTreeNode) children.nextElement();
    if (!dtm.isLeaf() && dtm.getLevel() <= level) {
        TreePath tp = new TreePath(dtm.getPath());
        tree.expandPath(tp);
        expandTree(tree, dtm, level);
return;
voidexpandTreeLevels(JTree tree, TreePath parent, boolean expand, int desiredLevel)
Expands all tree nodes or collapse these level by level. 
TreeNode node = (TreeNode) parent.getLastPathComponent();
if (node.getChildCount() >= 0) {
    for (Enumeration e = node.children(); e.hasMoreElements();) {
        TreeNode n = (TreeNode) e.nextElement();
        TreePath path = parent.pathByAddingChild(n);
        if (desiredLevel > 0)
            expandTreeLevels(tree, path, expand, desiredLevel - 1);
        else if (desiredLevel != 0)
...
voidexpandTreePaths(JTree tree, Enumeration expandPaths)
Used to restore expansion state of the tree like: 
 Enumeration expandPaths = tree.getExpandedDescendants(pathToRoot); // do some changes in the tree model ... 

if (expandPaths != null) {
    DefaultMutableTreeNode root = (DefaultMutableTreeNode) tree.getModel().getRoot();
    while (expandPaths.hasMoreElements()) {
        TreePath curPath = expandPaths.nextElement();
        DefaultMutableTreeNode castedNode = (DefaultMutableTreeNode) curPath.getLastPathComponent();
        Object obj = castedNode.getUserObject();
        Enumeration<?> enumAll = root.breadthFirstEnumeration();
        while (enumAll.hasMoreElements()) {
...
intfullExpand(JTree tree, TreePath parentPath, int nExpansions)
full Expand 
TreeNode parent = (TreeNode) parentPath.getLastPathComponent();
int count = parent.getChildCount();
for (int i = 0; i < count && nExpansions > 0; ++i) {
    TreeNode child = parent.getChildAt(i);
    TreePath childPath = parentPath.pathByAddingChild(child);
    nExpansions = fullExpand(tree, childPath, nExpansions);
tree.expandPath(parentPath);
...
CollectiongetExpandedPaths(JTree tree)
get Expanded Paths 
Collection<TreePath> set = new TreeSet<TreePath>(tpLengthComparator);
TreePath root = new TreePath(tree.getModel().getRoot());
if (root != null) {
    for (Enumeration<TreePath> e = tree.getExpandedDescendants(root); e != null && e.hasMoreElements();) {
        TreePath tp = e.nextElement();
        set.add(tp);
return set;
TreePath[]getExpandedPaths(JTree tree)
Get a copy of the list of expanded tree paths of a tree. 
ArrayList<TreePath> expandedPaths = new ArrayList<TreePath>();
TreePath rootPath = new TreePath(tree.getModel().getRoot());
Enumeration enumeration = tree.getExpandedDescendants(rootPath);
if (enumeration != null) {
    while (enumeration.hasMoreElements()) {
        expandedPaths.add((TreePath) enumeration.nextElement());
TreePath[] array = new TreePath[expandedPaths.size()];
expandedPaths.toArray(array);
return array;