maxActiveSlideAbsDelta property

@visibleForTesting double get maxActiveSlideAbsDelta

Test-only: the LARGER of the two engines' maxima (|currentDelta| ceilings), or 0.0 when both are idle.

NOT a bound on the composed per-row delta and deliberately not part of the production read surface: getSlideDeltaNid SUMS the FLIP engine and the make-room preview, so a row carrying both can exceed this max, the bug class every former consumer was migrated off of. Every window that must provably contain the composed painted positions (the render's build/paint/hit-test overreach widening, the bounded drop-target scan) reads composedSlideAbsDeltaBound (the sum). This getter is retained solely for tests that pin the max-vs-sum distinction: the make-room composition pin, and the bounded-scan oracle's teeth gate, which must prove its engineered overlap state exceeds a max-based bound, a value not derivable from any other public read.

Like composedSlideAbsDeltaBound, the preview half of this is the TERMINAL magnitude of each held offset, not its instantaneous one.

Implementation

@visibleForTesting
double get maxActiveSlideAbsDelta {
  final base = _slide.maxAbsDelta;
  if (!_preview.hasActive) {
    return base;
  }
  final previewMax = _preview.maxAbsDelta;
  return base > previewMax ? base : previewMax;
}