onPanStart method

void onPanStart(
  1. DragStartDetails details
)

Implementation

void onPanStart(DragStartDetails details) {
  RenderBox box = context.findRenderObject() as RenderBox;
  Offset firstPoint = box.globalToLocal(details.globalPosition);
  setState(() {
    lines.add(
      FreeLine([firstPoint], Colors.black, 2.0, StrokeCap.round)
    );
  });
}