Function on_drag_start 

pub fn on_drag_start(
    child: impl IntoUiNode,
    handler: Box<dyn FnMut(&DragStartArgs) -> HandlerResult + Send>,
) -> UiNode

P Draggable widget started dragging.

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

Preview

You can preview this event using on_pre_drag_start. Otherwise the handler is only called after the widget content has a chance to stop propagation.

Async

You can use async event handlers with this property.