Function on_drag_start 

pub fn on_drag_start(
    child: impl IntoUiNode,
    handler: Handler<DragStartArgs>,
) -> UiNode

P Draggable widget started dragging.

To receive this event in a widget set draggable to true.

Route

This event property uses the normal route, that is, the handler is called after the children widget handlers and after the $pn_pre_ident handlers.