public CheckboxBooleanQuestionInputView(BooleanQuestion question, SurveyPageAppearance appearance)
: base(appearance)
{
var option = new ToggleOption ();
option.HorizontalOptions = LayoutOptions.FillAndExpand;
option.VerticalOptions = LayoutOptions.CenterAndExpand;
option.UnselectedSource = appearance.UnselectedCheckboxImageSource;
option.SelectedSource = appearance.SelectedCheckboxImageSource;
option.BindingContext = question;
option.SetBinding (Option.TextProperty, new Binding ("Text", BindingMode.OneWay));
option.SetBinding (Option.IsSelectedProperty, new Binding ("Response", BindingMode.TwoWay));
Content = option;
}
