e1029. expanding or collapsing all nodes in a jtree component.txt

这里面包含了一百多个JAVA源文件

// If expand is true, expands all nodes in the tree.
    // Otherwise, collapses all nodes in the tree.
    public void expandAll(JTree tree, boolean expand) {
        TreeNode root = (TreeNode)tree.getModel().getRoot();
    
        // Traverse tree from root
        expandAll(tree, new TreePath(root), expand);
    }
    private void expandAll(JTree tree, TreePath parent, boolean expand) {
        // Traverse children
        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);
                expandAll(tree, path, expand);
            }
        }
    
        // Expansion or collapse must be done bottom-up
        if (expand) {
            tree.expandPath(parent);
        } else {
            tree.collapsePath(parent);
        }
    }