Result of an affordance hit — what the region computed about itself.
initialScratch is the payload: what the region already knows (which
corner, which target id) so the action that picks up the drag doesn't
re-derive it. <SceneCanvas> reads it out of the layer hit-test and packs
it into AffordanceHit, which flows to the matching action through
InvocationCtx.drag.affordance.
This used to also carry a drag: DragChannel naming the handlers the
tool-routing dispatcher should wire up. Every implementation supplied a
no-op stub that claimed, because the real routing had already moved to
bindings; the field went with that dispatcher.
Result of an affordance hit — what the region computed about itself.
initialScratchis the payload: what the region already knows (which corner, which target id) so the action that picks up the drag doesn't re-derive it.<SceneCanvas>reads it out of the layer hit-test and packs it intoAffordanceHit, which flows to the matching action throughInvocationCtx.drag.affordance.This used to also carry a
drag: DragChannelnaming the handlers the tool-routing dispatcher should wire up. Every implementation supplied a no-op stub that claimed, because the real routing had already moved to bindings; the field went with that dispatcher.