AnimatedSwitcher constructor Null safety

const AnimatedSwitcher(
  1. {Key? key,
  2. Widget? child,
  3. required Duration duration,
  4. Duration? reverseDuration,
  5. Curve switchInCurve = Curves.linear,
  6. Curve switchOutCurve = Curves.linear,
  7. AnimatedSwitcherTransitionBuilder transitionBuilder = AnimatedSwitcher.defaultTransitionBuilder,
  8. AnimatedSwitcherLayoutBuilder layoutBuilder = AnimatedSwitcher.defaultLayoutBuilder}
)

Creates an AnimatedSwitcher.

The duration, transitionBuilder, layoutBuilder, switchInCurve, and switchOutCurve parameters must not be null.

Implementation

const AnimatedSwitcher({
  Key? key,
  this.child,
  required this.duration,
  this.reverseDuration,
  this.switchInCurve = Curves.linear,
  this.switchOutCurve = Curves.linear,
  this.transitionBuilder = AnimatedSwitcher.defaultTransitionBuilder,
  this.layoutBuilder = AnimatedSwitcher.defaultLayoutBuilder,
}) : assert(duration != null),
     assert(switchInCurve != null),
     assert(switchOutCurve != null),
     assert(transitionBuilder != null),
     assert(layoutBuilder != null),
     super(key: key);