private Bundle notifyOnPreviousStep ( ) { Bundle result = null ; NavigationPreference selectedNavigationPreference = navigationFragment . getSelectedNavigationPreference ( ) ; if ( selectedNavigationPreference != null && preferenceFragment != null ) { for ( WizardListener listener : wizardListeners ) { Bundle bundle = listener . onPreviousStep ( selectedNavigationPreference , preferenceFragment , selectedPreferenceFragmentArguments ) ; if ( bundle != null ) { if ( result == null ) { result = new Bundle ( ) ; } result . putAll ( bundle ) ; } } } return result ; }
Notifies all registered listeners that the user wants to navigate to the previous step of the wizard .