public/zh/builder/src/echarts/processor/dataStack.js

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
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import { createHashMap, each } from 'zrender/src/core/util'; // (1) [Caution]: the logic is correct based on the premises:
//     data processing stage is blocked in stream.
//     See <module:echarts/stream/Scheduler#performDataProcessorTasks>
// (2) Only register once when import repeatly.
//     Should be executed before after series filtered and before stack calculation.

export default function (ecModel) {
  var stackInfoMap = createHashMap();
  ecModel.eachSeries(function (seriesModel) {
    var stack = seriesModel.get('stack'); // Compatibal: when `stack` is set as '', do not stack.

    if (stack) {
      var stackInfoList = stackInfoMap.get(stack) || stackInfoMap.set(stack, []);
      var data = seriesModel.getData();
      var stackInfo = {
        // Used for calculate axis extent automatically.
        stackResultDimension: data.getCalculationInfo('stackResultDimension'),
        stackedOverDimension: data.getCalculationInfo('stackedOverDimension'),
        stackedDimension: data.getCalculationInfo('stackedDimension'),
        stackedByDimension: data.getCalculationInfo('stackedByDimension'),
        isStackedByIndex: data.getCalculationInfo('isStackedByIndex'),
        data: data,
        seriesModel: seriesModel
      }; // If stacked on axis that do not support data stack.

      if (!stackInfo.stackedDimension || !(stackInfo.isStackedByIndex || stackInfo.stackedByDimension)) {
        return;
      }

      stackInfoList.length && data.setCalculationInfo('stackedOnSeries', stackInfoList[stackInfoList.length - 1].seriesModel);
      stackInfoList.push(stackInfo);
    }
  });
  stackInfoMap.each(calculateStack);
}

function calculateStack(stackInfoList) {
  each(stackInfoList, function (targetStackInfo, idxInStack) {
    var resultVal = [];
    var resultNaN = [NaN, NaN];
    var dims = [targetStackInfo.stackResultDimension, targetStackInfo.stackedOverDimension];
    var targetData = targetStackInfo.data;
    var isStackedByIndex = targetStackInfo.isStackedByIndex; // Should not write on raw data, because stack series model list changes
    // depending on legend selection.

    var newData = targetData.map(dims, function (v0, v1, dataIndex) {
      var sum = targetData.get(targetStackInfo.stackedDimension, dataIndex); // Consider `connectNulls` of line area, if value is NaN, stackedOver
      // should also be NaN, to draw a appropriate belt area.

      if (isNaN(sum)) {
        return resultNaN;
      }

      var byValue;
      var stackedDataRawIndex;

      if (isStackedByIndex) {
        stackedDataRawIndex = targetData.getRawIndex(dataIndex);
      } else {
        byValue = targetData.get(targetStackInfo.stackedByDimension, dataIndex);
      } // If stackOver is NaN, chart view will render point on value start.


      var stackedOver = NaN;

      for (var j = idxInStack - 1; j >= 0; j--) {
        var stackInfo = stackInfoList[j]; // Has been optimized by inverted indices on `stackedByDimension`.

        if (!isStackedByIndex) {
          stackedDataRawIndex = stackInfo.data.rawIndexOf(stackInfo.stackedByDimension, byValue);
        }

        if (stackedDataRawIndex >= 0) {
          var val = stackInfo.data.getByRawIndex(stackInfo.stackResultDimension, stackedDataRawIndex); // Considering positive stack, negative stack and empty data

          if (sum >= 0 && val > 0 || // Positive stack
          sum <= 0 && val < 0 // Negative stack
          ) {
              sum += val;
              stackedOver = val;
              break;
            }
        }
      }

      resultVal[0] = sum;
      resultVal[1] = stackedOver;
      return resultVal;
    });
    targetData.hostModel.setData(newData); // Update for consequent calculation

    targetStackInfo.data = newData;
  });
}