dragStartBehavior property
Configure the behavior of offsets sent to onStart.
If set to DragStartBehavior.start, the onStart callback will be called at the time and position when this gesture recognizer wins the arena. If DragStartBehavior.down, onStart will be called at the time and position when a down event was first detected.
For more information about the gesture arena: https://flutter.dev/docs/development/ui/advanced/gestures#gesture-disambiguation
By default, the drag start behavior is DragStartBehavior.start.
Example:
A finger presses down on the screen with offset (500.0, 500.0), and then moves to position (510.0, 500.0) before winning the arena. With dragStartBehavior set to DragStartBehavior.down, the onStart callback will be called at the time corresponding to the touch's position at (500.0, 500.0). If it is instead set to DragStartBehavior.start, onStart will be called at the time corresponding to the touch's position at (510.0, 500.0).
Implementation
DragStartBehavior dragStartBehavior;