message: Calculated scroll edge props
  The props can be functions now that accept a large boolean. Pass title color and large title color, for example
diff: @@ -8,12 +8,32 @@ import CollapsingBar from './CollapsingBar';
  import TabBar from './TabBar';
  import StatusBar from './StatusBar';
  +var getValue = (prop: string | ((large: boolean) => string), large: boolean) => (
  + typeof prop === 'function' ? prop(large) : prop
  +)
  +
  class NavigationBar extends React.Component<any, any> {
  constructor(props) {
  super(props);
  }
  render() {
  - var {hidden, logo, navigationImage, overflowImage, children, style = {height: undefined}, ...otherProps} = this.props;
  + var {hidden, logo, navigationImage, overflowImage, barTintColor, titleColor,
  + titleFontFamily, titleFontWeight, titleFontStyle, titleFontSize,
  + children, style = {height: undefined}, ...otherProps} = this.props;
  + var scrollEdgeProps = {
  + barTintColor: getValue(barTintColor, false),
  + largeBarTintColor: getValue(barTintColor, true),
  + titleColor: getValue(titleColor, false),
  + largeTtleColor: getValue(titleColor, true),
  + titleFontFamily: getValue(titleFontFamily, false),
  + largeTitleFontFamily: getValue(titleFontFamily, true),
  + titleFontWeight: getValue(titleFontWeight, false),
  + largeTitleFontWeight: getValue(titleFontWeight, true),
  + titleFontStyle: getValue(titleFontStyle, false),
  + largeTitleFontStyle: getValue(titleFontStyle, true),
  + titleFontSize: getValue(titleFontSize, false),
  + largeTitleFontSize: getValue(titleFontSize, true)
  + }
  var childrenArray = (React.Children.toArray(children) as ReactElement<any>[]);
  var statusBar = childrenArray.find(({type}) => type === StatusBar);
  statusBar = (Platform.OS === 'android' || !statusBar) && (statusBar || <StatusBar />);
  @@ -25,6 +45,7 @@ class NavigationBar extends React.Component<any, any> {
  <NVNavigationBar
  hidden={hidden}
  style={{height: Platform.OS === 'android' && collapsingBar ? style.height : null}}
  + {...scrollEdgeProps}
  {...otherProps}>
  {Platform.OS === 'ios' ? !hidden && children :
  <Container
  