# File lib/json/editor.rb, line 231
231:       def add_item(label, keyval = nil, klass = MenuItem, &callback)
232:         label = "#{label} (C-#{keyval.chr})" if keyval
233:         item = klass.new(label)
234:         item.signal_connect(:activate, &callback)
235:         if keyval
236:           self.signal_connect('key-press-event''key-press-event') do |item, event|
237:             if event.state & Gdk::Window::ModifierType::CONTROL_MASK != 0 and
238:               event.keyval == keyval
239:               callback.call item
240:             end
241:           end
242:         end
243:         menu.append item
244:         item
245:       end