DragUpdateDetails constructor Null safety
Creates details for a DragUpdateDetails.
The delta argument must not be null.
If primaryDelta is non-null, then its value must match one of the coordinates of delta and the other coordinate must be zero.
The globalPosition argument must be provided and must not be null.
Implementation
DragUpdateDetails({
this.sourceTimeStamp,
this.delta = Offset.zero,
this.primaryDelta,
required this.globalPosition,
Offset? localPosition,
}) : assert(delta != null),
assert(
primaryDelta == null
|| (primaryDelta == delta.dx && delta.dy == 0.0)
|| (primaryDelta == delta.dy && delta.dx == 0.0),
),
localPosition = localPosition ?? globalPosition;