ScrollSpeedController typedef Null safety

ScrollSpeedController = double Function(int timeInMilliSecond, double overSize, double itemSize)

Control the scroll speed if drag over the boundary. We can pass time here?? timeInMilliSecond is the time passed. overPercentage is the scroll over the boundary percentage overSize is the pixel drag over the boundary itemSize is the drag item size Maybe you need decide the scroll speed by the given param. return how many pixels when scroll in 14ms(maybe a frame). 5 is the default

Implementation

typedef ScrollSpeedController = double Function(int timeInMilliSecond, double overSize, double itemSize);