java Swing JTree之 展开 关闭

java Swing JTree之 展开 关闭

 

/**
     * 展开一棵树
     * @param tree
     */
    private void expandTree(JTree tree) {
        // 根节点

        TreeNode node = (TreeNode) tree.getModel().getRoot();
        expandAll(tree, new TreePath(node), false);
    }

    /**
     * 完全展开一棵树或关闭一棵树
     * @param tree JTree
     * @param parent 父节点
     * @param expand true 表示展开，false 表示关闭
     */
    private void expandAll(JTree tree, TreePath parent, boolean expand) {
        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);
            }
        }
        if (expand) {
            tree.expandPath(parent);
        } else {
            tree.collapsePath(parent);
        }
    }