question: private void reflectMemberVariablesInFinalButton ( ) { final boolean lastPageReached = ( viewPager . getCurrentItem ( ) + 1 ) == pages . size ( ) ; final boolean buttonShouldBeInvisible = ! lastPageReached || finalButtonDisabled ; final boolean buttonIsCurrentlyInvisible = finalButton . getVisibility ( ) == View . INVISIBLE ; final boolean shouldUpdateButton = buttonShouldBeInvisible != buttonIsCurrentlyInvisible ; if ( shouldUpdateButton ) { final Animator buttonAnimator = buttonShouldBeInvisible ? buttonAnimatorFactory . newFinalButtonDisappearAnimator ( finalButton ) : buttonAnimatorFactory . newFinalButtonAppearAnimator ( finalButton ) ; if ( buttonShouldBeInvisible ) { disableButton ( buttonAnimator , finalButton ) ; } else { enableButton ( buttonAnimator , finalButton ) ; } } }
target:  Enables or disables the final button, so that it matches the current member variables.