public/zh/builder/src/echarts/chart/helper/LineDraw.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
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

/**
 * @module echarts/chart/helper/LineDraw
 */
import * as graphic from '../../util/graphic';
import LineGroup from './Line'; // import IncrementalDisplayable from 'zrender/src/graphic/IncrementalDisplayable';

/**
 * @alias module:echarts/component/marker/LineDraw
 * @constructor
 */

function LineDraw(ctor) {
  this._ctor = ctor || LineGroup;
  this.group = new graphic.Group();
}

var lineDrawProto = LineDraw.prototype;

lineDrawProto.isPersistent = function () {
  return true;
};
/**
 * @param {module:echarts/data/List} lineData
 */


lineDrawProto.updateData = function (lineData) {
  var lineDraw = this;
  var group = lineDraw.group;
  var oldLineData = lineDraw._lineData;
  lineDraw._lineData = lineData; // There is no oldLineData only when first rendering or switching from
  // stream mode to normal mode, where previous elements should be removed.

  if (!oldLineData) {
    group.removeAll();
  }

  var seriesScope = makeSeriesScope(lineData);
  lineData.diff(oldLineData).add(function (idx) {
    doAdd(lineDraw, lineData, idx, seriesScope);
  }).update(function (newIdx, oldIdx) {
    doUpdate(lineDraw, oldLineData, lineData, oldIdx, newIdx, seriesScope);
  }).remove(function (idx) {
    group.remove(oldLineData.getItemGraphicEl(idx));
  }).execute();
};

function doAdd(lineDraw, lineData, idx, seriesScope) {
  var itemLayout = lineData.getItemLayout(idx);

  if (!lineNeedsDraw(itemLayout)) {
    return;
  }

  var el = new lineDraw._ctor(lineData, idx, seriesScope);
  lineData.setItemGraphicEl(idx, el);
  lineDraw.group.add(el);
}

function doUpdate(lineDraw, oldLineData, newLineData, oldIdx, newIdx, seriesScope) {
  var itemEl = oldLineData.getItemGraphicEl(oldIdx);

  if (!lineNeedsDraw(newLineData.getItemLayout(newIdx))) {
    lineDraw.group.remove(itemEl);
    return;
  }

  if (!itemEl) {
    itemEl = new lineDraw._ctor(newLineData, newIdx, seriesScope);
  } else {
    itemEl.updateData(newLineData, newIdx, seriesScope);
  }

  newLineData.setItemGraphicEl(newIdx, itemEl);
  lineDraw.group.add(itemEl);
}

lineDrawProto.updateLayout = function () {
  var lineData = this._lineData; // Do not support update layout in incremental mode.

  if (!lineData) {
    return;
  }

  lineData.eachItemGraphicEl(function (el, idx) {
    el.updateLayout(lineData, idx);
  }, this);
};

lineDrawProto.incrementalPrepareUpdate = function (lineData) {
  this._seriesScope = makeSeriesScope(lineData);
  this._lineData = null;
  this.group.removeAll();
};

lineDrawProto.incrementalUpdate = function (taskParams, lineData) {
  function updateIncrementalAndHover(el) {
    if (!el.isGroup) {
      el.incremental = el.useHoverLayer = true;
    }
  }

  for (var idx = taskParams.start; idx < taskParams.end; idx++) {
    var itemLayout = lineData.getItemLayout(idx);

    if (lineNeedsDraw(itemLayout)) {
      var el = new this._ctor(lineData, idx, this._seriesScope);
      el.traverse(updateIncrementalAndHover);
      this.group.add(el);
      lineData.setItemGraphicEl(idx, el);
    }
  }
};

function makeSeriesScope(lineData) {
  var hostModel = lineData.hostModel;
  return {
    lineStyle: hostModel.getModel('lineStyle').getLineStyle(),
    hoverLineStyle: hostModel.getModel('emphasis.lineStyle').getLineStyle(),
    labelModel: hostModel.getModel('label'),
    hoverLabelModel: hostModel.getModel('emphasis.label')
  };
}

lineDrawProto.remove = function () {
  this._clearIncremental();

  this._incremental = null;
  this.group.removeAll();
};

lineDrawProto._clearIncremental = function () {
  var incremental = this._incremental;

  if (incremental) {
    incremental.clearDisplaybles();
  }
};

function isPointNaN(pt) {
  return isNaN(pt[0]) || isNaN(pt[1]);
}

function lineNeedsDraw(pts) {
  return !isPointNaN(pts[0]) && !isPointNaN(pts[1]);
}

export default LineDraw;