maxExtent property

@override double get maxExtent

The size of the header when it is not shrinking at the top of the viewport.

This must return a value equal to or greater than minExtent.

This value should not change over the lifetime of the delegate. It should be based entirely on the constructor arguments passed to the delegate. See shouldRebuild, which must return true if a new delegate would return a different value.

Implementation

@override
double get maxExtent => _size!;