Construct a rectangle from its left and top edges, its width, and its height.
To construct a Rect from an Offset and a Size, you can use the
rectangle constructor operator &
. See Offset.&.
Source
Rect.fromLTWH(double left, double top, double width, double height) { _value ..[0] = left ..[1] = top ..[2] = left + width ..[3] = top + height; }