FlexibleSpaceBarSettings constructor Null safety

const FlexibleSpaceBarSettings(
  1. {Key? key,
  2. required double toolbarOpacity,
  3. required double minExtent,
  4. required double maxExtent,
  5. required double currentExtent,
  6. required Widget child,
  7. bool? isScrolledUnder}
)

Creates a Flexible Space Bar Settings widget.

Used by Scaffold and SliverAppBar. child must have a FlexibleSpaceBar widget in its tree for the settings to take affect.

The required toolbarOpacity, minExtent, maxExtent, currentExtent, and child parameters must not be null.

Implementation

const FlexibleSpaceBarSettings({
  Key? key,
  required this.toolbarOpacity,
  required this.minExtent,
  required this.maxExtent,
  required this.currentExtent,
  required Widget child,
  this.isScrolledUnder,
}) : assert(toolbarOpacity != null),
     assert(minExtent != null && minExtent >= 0),
     assert(maxExtent != null && maxExtent >= 0),
     assert(currentExtent != null && currentExtent >= 0),
     assert(toolbarOpacity >= 0.0),
     assert(minExtent <= maxExtent),
     assert(minExtent <= currentExtent),
     assert(currentExtent <= maxExtent),
     super(key: key, child: child);