Module hit_target 

The canvas hit-test z-order, encoded once.

Every pointer gesture — hover, click, double-click, drag — asks Drawing::resolve_at_pos what is under the cursor and reacts to the answer. Tools keep their reactions (which tool to switch to); none of them re-derives what was hit, so hover, click and drag can never disagree about it.

Two orders meet here. Across kinds the priority is editorial — labels beat the bodies they sit on, a port beats a route crossing it — and Drawing::resolve_at_pos is the only place it is written down. Within a kind there is no separate hit order at all: hit order is draw order back to front, so the shape painted last is tested first (Drawing::hit_candidates, the document’s one chronological order reversed). Every fine-phase test lives here too, so the priorities and the tests they order can be read together.

Enums

HitTarget

What sits at a point on the canvas, resolved top-down.

PinPart

Which part of a pin was hit. The stub is last so a tag drawn over it (the tag rises only a few pixels above the stub line) stays double-clickable.

Constants

LABEL_HIT_PAD 🔒

Slack added around a drawn label’s text extent when hit-testing it, so small text is comfortably clickable.