onDragStart property

void Function(DragStartDetails details) onDragStart
final

Called when a drag operation starts.

Receives DragStartDetails with the start position. Use this to:

  • Set the dragged element ID in the controller
  • Select the element if not already selected
  • Disable canvas panning
  • Calculate connection start point (for ports)

Implementation

final void Function(DragStartDetails details) onDragStart;