append_new_node

# File ext/json/lib/json/editor.rb, line 388
      def append_new_node(item)
        if parent = selection.selected
          parent_type = parent.type
          case parent_type
          when 'Hash'
            key, type, content = ask_for_hash_pair(parent)
            key or return
            iter = create_node(parent, 'Key', key)
            iter = create_node(iter, type, content)
            toplevel.display_status(
              "Added a (key, value)-pair to '#{parent_type}'.")
            window.change
          when 'Array'
            type, content = ask_for_element(parent)
            type or return
            iter = create_node(parent, type, content)
            window.change
            toplevel.display_status("Appendend an element to '#{parent_type}'.")
          else
            toplevel.display_status("Cannot append to '#{parent_type}'!")
          end
        else
          type, content = ask_for_element
          type or return
          iter = create_node(nil, type, content)
          window.change
        end
      end