private boolean isMoveActionEnabled(int increment) {
    final DefaultMutableTreeNode[] selectedNodes = myTree.getSelectedNodes(DefaultMutableTreeNode.class, null);
    if (selectedNodes.length == 0) return false;

    boolean enabled = true;
    for (DefaultMutableTreeNode node : selectedNodes) {
      final DefaultMutableTreeNode sibling = increment == -1 ? node.getPreviousSibling() : node.getNextSibling();
      enabled = enabled && (node.getUserObject() instanceof TaskNode) && sibling != null;
    }
    if (!enabled) {
      enabled = true;
      for (DefaultMutableTreeNode node : selectedNodes) {
        final DefaultMutableTreeNode sibling = increment == -1 ? node.getPreviousSibling() : node.getNextSibling();
        enabled = enabled && (node.getUserObject() instanceof ProjectNode) && sibling != null;
      }
    }
    return enabled;
  }
private boolean isMoveActionEnabled(int increment)