onScaleUpdate method

void onScaleUpdate(ScaleUpdateDetails details)

Implementation

void onScaleUpdate(ScaleUpdateDetails details) {
  if (details.pointerCount < 2 || details.rotation == 0) {
    //滑动
    if (_dragFirst) {
      _dragFirst = false;
      ScaleStartDetails fd = _dragDetails!;
      double dx = details.focalPoint.dx - fd.focalPoint.dx;
      double dy = details.focalPoint.dy - fd.focalPoint.dy;
      double at = (atan2(dy, dx) * 180 / pi).abs();
      NormalEvent eventH = NormalEvent(details.localFocalPoint, null);
      NormalEvent eventV = NormalEvent(details.localFocalPoint,  null);
      _dragDirection = at < 45 ? Direction.horizontal : Direction.vertical;
      Set<ChartGesture> removeList = {};
      for (var ele in _dragNodeList) {
        if (!ele.isInArea(details.focalPoint)) {
          removeList.add(ele);
        } else {
          if (_dragDirection == Direction.horizontal) {
            ele.horizontalDragStart?.call(eventH);
          } else {
            ele.verticalDragStart?.call(eventV);
          }
        }
      }
      if (removeList.isNotEmpty) {
        _dragNodeList.removeAll(removeList);
      }
    } else {
      NormalEvent eventH = NormalEvent(details.localFocalPoint, null);
      NormalEvent eventV = NormalEvent(details.localFocalPoint,  null);
      Set<ChartGesture> removeList = {};
      for (var ele in _dragNodeList) {
        if (!ele.isInArea(details.focalPoint)) {
          removeList.add(ele);
          if (_dragDirection == Direction.horizontal) {
            ele.horizontalDragCancel?.call();
          } else {
            ele.verticalDragCancel?.call();
          }
        } else {
          if (_dragDirection == Direction.horizontal) {
            ele.horizontalDragMove?.call(eventH);
          } else {
            ele.verticalDragMove?.call(eventV);
          }
        }
      }
      if (removeList.isNotEmpty) {
        _dragNodeList.removeAll(removeList);
      }
    }
    return;
  }

  ///缩放
  Set<ChartGesture> removeSet = {};
  ScaleEvent motionEvent = ScaleEvent(
    details.scale,
    details.horizontalScale,
    details.verticalScale,
    details.rotation,
    details.localFocalPoint,
    null);
  for (var ele in _scaleNodeList) {
    if (!ele.isInArea(motionEvent.globalPosition)) {
      removeSet.add(ele);
      ele.scaleCancel?.call();
    } else {
      ele.scaleUpdate?.call(motionEvent);
    }
  }
  if (removeSet.isNotEmpty) {
    _scaleNodeList.removeAll(removeSet);
  }
}