/// Defines if it is supposed that the widget should interact with the viewer.
virtual bool isViewerSelector() { return true; }
/// Defines if it is supposed that the widget should interact with the viewer.
virtual bool isViewerSelector() { return true; }
/// Checks the widget validity. By default, it returns true.
/// \param thePrs a selected presentation in the view
/// \return a boolean value
/// Checks the widget validity. By default, it returns true.
/// \param thePrs a selected presentation in the view
/// \return a boolean value