CupertinoNavigationBar constructor Null safety

const CupertinoNavigationBar(
  1. {Key? key,
  2. Widget? leading,
  3. bool automaticallyImplyLeading = true,
  4. bool automaticallyImplyMiddle = true,
  5. String? previousPageTitle,
  6. Widget? middle,
  7. Widget? trailing,
  8. Border? border = _kDefaultNavBarBorder,
  9. Color? backgroundColor,
  10. Brightness? brightness,
  11. EdgeInsetsDirectional? padding,
  12. bool transitionBetweenRoutes = true,
  13. Object heroTag = _defaultHeroTag}
)

Creates a navigation bar in the iOS style.

Implementation

const CupertinoNavigationBar({
  super.key,
  this.leading,
  this.automaticallyImplyLeading = true,
  this.automaticallyImplyMiddle = true,
  this.previousPageTitle,
  this.middle,
  this.trailing,
  this.border = _kDefaultNavBarBorder,
  this.backgroundColor,
  this.brightness,
  this.padding,
  this.transitionBetweenRoutes = true,
  this.heroTag = _defaultHeroTag,
}) : assert(automaticallyImplyLeading != null),
     assert(automaticallyImplyMiddle != null),
     assert(transitionBetweenRoutes != null),
     assert(
       heroTag != null,
       'heroTag cannot be null. Use transitionBetweenRoutes = false to '
       'disable Hero transition on this navigation bar.',
     ),
     assert(
       !transitionBetweenRoutes || identical(heroTag, _defaultHeroTag),
       'Cannot specify a heroTag override if this navigation bar does not '
       'transition due to transitionBetweenRoutes = false.',
     );