Creates a ScrollSimulation with the given parameters.
The position and velocity arguments must use the same units as will be expected from the x and dx methods respectively.
The leading and trailing extents must use the unit of length, the same unit as used for the position argument and as expected from the x method.
The units used with the provided SpringDescription must similarly be consistent with the other arguments.
The final argument is the coefficient of friction, which is unitless.
Source
ScrollSimulation({
double position,
double velocity,
double leadingExtent,
double trailingExtent,
SpringDescription spring,
double drag,
TargetPlatform platform,
}) : _leadingExtent = leadingExtent,
_trailingExtent = trailingExtent,
_spring = spring ?? _kScrollSpring,
_drag = drag ?? _kDrag,
_platform = platform {
assert(_leadingExtent != null);
assert(_trailingExtent != null);
assert(_spring != null);
_chooseSimulation(position, velocity, 0.0);
}