maxSimultaneousDrags property
How many simultaneous drags to support.
When null, no limit is applied. Set this to 1 if you want to only allow the drag source to have one item dragged at a time. Set this to 0 if you want to prevent the draggable from actually being dragged.
If you set this property to 1, consider supplying an "empty" widget for
childWhenDragging to create the illusion of actually moving child
.
Implementation
final int? maxSimultaneousDrags;