onPanUpdate method

bool onPanUpdate(DragUpdateDetails details, { required double availableHeight, })

Returns true if the event was consumed by a vertical morph gesture.

Implementation

bool onPanUpdate(
  DragUpdateDetails details, {
  required double availableHeight,
}) {
  _accumulated += details.delta;

  // Record sample for predictive analysis
  _sampleBuffer.addLast(
    _GestureSample(details.delta, details.sourceTimeStamp ?? Duration.zero),
  );
  if (_sampleBuffer.length > _maxSamples) {
    _sampleBuffer.removeFirst();
  }

  if (_lockedAxis == _DragAxis.none) {
    final dx = _accumulated.dx.abs();
    final dy = _accumulated.dy.abs();
    final total = math.sqrt(dx * dx + dy * dy);

    if (total < lockThreshold) return false;

    // Use predictive axis detection combining delta + velocity analysis
    _lockedAxis = _predictAxis(details);

    if (_lockedAxis == _DragAxis.vertical) {
      morphController.startDrag();
      _verticalStarted = true;
    }
  }

  if (_lockedAxis == _DragAxis.vertical) {
    // Apply rubber-band when dragging beyond boundaries
    double delta = details.delta.dy;
    final progress = morphController.progress;
    if ((progress <= 0.05 && delta > 0 && delta.abs() < 3) ||
        (progress >= 0.95 && delta < 0)) {
      delta *= rubberBandFactor;
    }
    morphController.updateDrag(delta, availableHeight);
    return true;
  }

  return false;
}