asyncInitWithOutAnimal method

Map<int, LineInfo> asyncInitWithOutAnimal(ChartsState state)

Implementation

Map<int, LineInfo> asyncInitWithOutAnimal(ChartsState state) {
  ChartDimensionCoordinateState layout = state.layout as ChartDimensionCoordinateState;
  chartState.children = [];
  int index = 0;
  //offset.dx 滚动偏移  (src.zoom - 1) * (src.size.width / 2) 缩放
  double left = layout.left;
  double right = layout.right;
  double top = layout.top;
  double bottom = layout.bottom;
  Map<int, LineInfo> pathMap = {};
  ChartItemLayoutState? lastShape;
  num? lastXValue;
  //遍历数据 处理数据信息
  for (T value in data) {
    ChartLineLayoutState currentPointLayout = ChartLineLayoutState();
    currentPointLayout.layout = layout;
    currentPointLayout.xAxis = layout.xAxis;
    currentPointLayout.yAxis = layout.yAxis;
    currentPointLayout.yAxisPosition = yAxisPosition;
    chartState.children.add(currentPointLayout);
    //获取原数据
    num? xValue = _instance.position.call(value);
    if (lastXValue != null) {
      assert(lastXValue < xValue, '$xValue 必须大于 $lastXValue,（虽然可以支持逆序，但是为了防止数据顺序混乱，还是强制要求必须是正序的数组)');
    }
    List<num>? yValues = currentPointLayout.yValues;
    yValues ??= _instance.values.call(value);

    //保存数据
    currentPointLayout.index = index;
    currentPointLayout.xValue = xValue;
    currentPointLayout.yValues = yValues;

    assert(_instance.colors.length >= yValues.length, '颜色配置跟数据源不匹配');
    assert(_instance.shaders == null || _instance.shaders!.length >= yValues.length, '颜色配置跟数据源不匹配');

    //计算x轴和y轴的物理位置
    double xPos = xValue * layout.xAxis.density;
    //一组数据下可能多条线
    for (int valueIndex = 0; valueIndex < yValues.length; valueIndex++) {
      //每条线用map存放下，以便后面统一绘制
      LineInfo? lineInfo = pathMap[valueIndex];
      if (lineInfo == null) {
        lineInfo = LineInfo(_instance.isCurve);
        pathMap[valueIndex] = lineInfo;
      }
      //计算点的位置
      num yValue = yValues[valueIndex];
      //y轴位置
      double yPos = bottom - layout.yAxis[yAxisPosition].getHeight(yValue);
      Offset currentPoint = Offset(xPos, yPos);
      lineInfo.startPoint ??= currentPoint;

      //点的信息
      ChartLineLayoutState childLayoutState;
      if (valueIndex < currentPointLayout.children.length) {
        childLayoutState = currentPointLayout.children[valueIndex] as ChartLineLayoutState;
      } else {
        childLayoutState = ChartLineLayoutState();
        currentPointLayout.children.add(childLayoutState);
      }

      childLayoutState.setOriginRect(Rect.fromCenter(center: currentPoint, width: _instance.dotRadius, height: _instance.dotRadius));
      childLayoutState.index = index;
      childLayoutState.layout = layout;
      childLayoutState.xAxis = layout.xAxis;
      childLayoutState.yAxis = layout.yAxis;
      childLayoutState.yAxisPosition = yAxisPosition;
      childLayoutState.xValue = xValue;
      childLayoutState.yValue = yValue;
      //存放点的位置
      lineInfo.appendPoint(childLayoutState);
    }

    Rect currentRect = Rect.fromLTRB(xPos - _instance.dotRadius, top, xPos + _instance.dotRadius, bottom);
    currentPointLayout.setOriginRect(currentRect);
    currentPointLayout.left = left;
    currentPointLayout.right = right;
    //这里用链表解决查找附近节点的问题
    currentPointLayout.preShapeState = lastShape;
    lastShape?.nextShapeState = currentPointLayout;
    lastShape = currentPointLayout;
    //放到最后
    index++;
    lastXValue = xValue;
  }
  return pathMap;
}