set-value in check-box%

Sets the check box's state. (The control's callback procedure is not invoked.)

The check box's state can be changed by the user clicking the control, and such changes do not go through this method; use the control callback procedure (provided as an initialization argument) to monitor state changes.

• (send a-check-box set-value state) -> void
     state : boolean

  If state is #f, the box is unchecked, otherwise it is checked.