getHeldPreviewDeltaNid method

double getHeldPreviewDeltaNid(
  1. int nid
)

Internal-use-only: the HELD make-room preview offset for the live nid, EXCLUDING any in-flight FLIP delta. 0.0 when no drag preview touches the row.

GHOST-GEOMETRY READ. The identity getSlideDeltaNid == getFlipSlideDeltaNid + getHeldPreviewDeltaNid holds by construction, which is what keeps "painted position is structural + FLIP + preview" intact at the one site that has to SPLIT the composed delta rather than choose a half of it: an exit ghost converges on its anchor's SETTLED position, so it must follow the anchor's held displacement while ignoring its decaying one.

Implementation

double getHeldPreviewDeltaNid(int nid) {
  if (!_preview.hasActive) {
    return 0.0;
  }
  return _preview.deltaForNid(nid);
}