moveCorner method
Implementation
void moveCorner(Key key, QuadCorner corner, LatLng to, {bool merge = false}) {
final before = findByKey(key);
if (before == null) {
debugPrint(
'Warning: Attempted to move corner of non-existent overlay with key: $key');
return;
}
final from = before.corners.pointAt(corner);
perform(
MoveCornerOverlayOp(key: key, corner: corner, from: from, to: to),
merge: merge,
);
// Debounced feedback can be added here if needed,
// or via logic.onDragUpdate if we generalize corner drag.
_options.onSpatialUpdate?.call(
findByKey(key)!,
before,
);
scheduleAutoSave();
}