Type Alias ExternalDragPayloadSource 

pub type ExternalDragPayloadSource = Box<dyn FnOnce(&mut Window, &mut App) -> Option<ExternalDragPayload> + 'static>;

A closure that builds the payload for a drag that leaves the window.

It runs when the drag becomes a native drag session, not when the drag starts. Set it with AnyDrag::external_payload.

Aliased Type

pub struct ExternalDragPayloadSource(/* private fields */);