Function axisSelectionLayer

docs/tests/v2/es6/js/sanddance.js:148934–148986

(presenter, specCapabilities, columns, stage, clickHandler, highlightColor, polygonZ)

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT license.
function axisSelectionLayer(presenter, specCapabilities, columns, stage, clickHandler, highlightColor, polygonZ) {
  const polygons = [];
  const xRole = specCapabilities.roles.filter(r => r.role === 'x')[0];

  if (xRole && xRole.axisSelection) {
    stage.axes.x.filter(axis => axis.tickText.length).forEach(axis => {
      polygons.push.apply(polygons, axisSelectionPolygons(axis, false, xRole.axisSelection, columns.x));
    });
  }

  const yRole = specCapabilities.roles.filter(r => r.role === 'y')[0];

  if (yRole && yRole.axisSelection) {
    stage.axes.y.filter(axis => axis.tickText.length).forEach(axis => {
      polygons.push.apply(polygons, axisSelectionPolygons(axis, true, yRole.axisSelection, columns.y));
    });
  }

  if (stage.facets) {
    polygons.push.apply(polygons, facetSelectionPolygons(stage.facets, columns.facet));
  } //move polygons to Z


  polygons.forEach(datum => {
    datum.polygon.forEach(p => {
      p[2] = polygonZ;
    });
  });

  const onClick = (o, e) => clickHandler(e.srcEvent, o.object.search);

  const polygonLayer = new VegaDeckGl.base.layers.PolygonLayer({
    autoHighlight: true,
    coordinateSystem: VegaDeckGl.base.deck.COORDINATE_SYSTEM.IDENTITY,
    data: polygons,
    extruded: false,
    highlightColor,
    id: 'selections',
    onHover: (o, e) => {
      if (o.index === -1) {
        presenter.deckgl.interactiveState.onAxisSelection = false;
      } else {
        presenter.deckgl.interactiveState.onAxisSelection = true;
      }
    },
    onClick,
    getElevation: () => 0,
    getFillColor: () => [0, 0, 0, 0],
    pickable: true,
    stroked: false
  });
  return polygonLayer;
}

function axisSelectionPolygons(axis, vertical, axisSelectionType, column) {
  const polygons = [];