When an initial event is passed, the first drag will be triggered immediately using the coordinates therein. This
is useful when the drag is initiated by a mousedown/touchstart event but you want the initial "click" to activate
a drag (e.g. positioning a handle initially at the click target).
When an initial event is passed, the first drag will be triggered immediately using the coordinates therein. This is useful when the drag is initiated by a mousedown/touchstart event but you want the initial "click" to activate a drag (e.g. positioning a handle initially at the click target).