* Bound controls provide a way for user input but they differ from standard controls in their behavior. When data is input in a bound control it is automatically validated. If it is correct it is put in the undo/redo mechanism and the information in the bound control is sent to the bound data holder(the control model). This transition is two-way. Bound controls are composed of a standard control, an icon and optionally a label. They allow to attach a model and a verification mechanism. The icon shows the verification status. It can be either correct (a green tick) or incorrect (a red cross.)
 * We need:
  * Text box
  * Drop-down list
  * Spinner
  * Check-box