ScaleUpdateDetails constructor Null safety
Creates details for GestureScaleUpdateCallback.
The focalPoint, scale, horizontalScale, verticalScale, rotation arguments must not be null. The scale, horizontalScale, and verticalScale argument must be greater than or equal to zero.
Implementation
ScaleUpdateDetails({
this.focalPoint = Offset.zero,
Offset? localFocalPoint,
this.scale = 1.0,
this.horizontalScale = 1.0,
this.verticalScale = 1.0,
this.rotation = 0.0,
this.pointerCount = 0,
this.focalPointDelta = Offset.zero,
}) : assert(focalPoint != null),
assert(focalPointDelta != null),
assert(scale != null && scale >= 0.0),
assert(horizontalScale != null && horizontalScale >= 0.0),
assert(verticalScale != null && verticalScale >= 0.0),
assert(rotation != null),
localFocalPoint = localFocalPoint ?? focalPoint;