[Maps] Remove client-side scaling of ordinal values (#58528)

This removes the rescaling of ordinal values to the [0,1] domain, and modifies the creation of the mapbox-style rules to use the actual RangeStyleMeta-data. This is an important prerequisite for Maps handling tile vector sources. For these sources, Maps does not have access to the raw underlying GeoJson and needs to use the stylemeta directly.
elastic · Mar 23, 2020 · 88d41fa · 88d41fa
1 parent d32c4c8
commit 88d41fa
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Showing 17 changed files with 335 additions and 252 deletions.
diff --git a/x-pack/legacy/plugins/maps/public/layers/heatmap_layer.js b/x-pack/legacy/plugins/maps/public/layers/heatmap_layer.js
@@ -72,7 +72,7 @@ export class HeatmapLayer extends VectorLayer {
     const propertyKey = this._getPropKeyOfSelectedMetric();
     const dataBoundToMap = AbstractLayer.getBoundDataForSource(mbMap, this.getId());
     if (featureCollection !== dataBoundToMap) {
-      let max = 0;
+      let max = 1; //max will be at least one, since counts or sums will be at least one.
       for (let i = 0; i < featureCollection.features.length; i++) {
         max = Math.max(featureCollection.features[i].properties[propertyKey], max);
       }

diff --git a/x-pack/legacy/plugins/maps/public/layers/styles/color_utils.js b/x-pack/legacy/plugins/maps/public/layers/styles/color_utils.js
@@ -78,17 +78,26 @@ export function getColorRampCenterColor(colorRampName) {
 
 // Returns an array of color stops
 // [ stop_input_1: number, stop_output_1: color, stop_input_n: number, stop_output_n: color ]
-export function getOrdinalColorRampStops(colorRampName, numberColors = GRADIENT_INTERVALS) {
+export function getOrdinalColorRampStops(colorRampName, min, max) {
   if (!colorRampName) {
     return null;
   }
-  return getHexColorRangeStrings(colorRampName, numberColors).reduce(
-    (accu, stopColor, idx, srcArr) => {
-      const stopNumber = idx / srcArr.length; // number between 0 and 1, increasing as index increases
-      return [...accu, stopNumber, stopColor];
-    },
-    []
-  );
+
+  if (min > max) {
+    return null;
+  }
+
+  const hexColors = getHexColorRangeStrings(colorRampName, GRADIENT_INTERVALS);
+  if (max === min) {
+    //just return single stop value
+    return [max, hexColors[hexColors.length - 1]];
+  }
+
+  const delta = max - min;
+  return hexColors.reduce((accu, stopColor, idx, srcArr) => {
+    const stopNumber = min + (delta * idx) / srcArr.length;
+    return [...accu, stopNumber, stopColor];
+  }, []);
 }
 
 export const COLOR_GRADIENTS = Object.keys(vislibColorMaps).map(colorRampName => ({

diff --git a/x-pack/legacy/plugins/maps/public/layers/styles/color_utils.test.js b/x-pack/legacy/plugins/maps/public/layers/styles/color_utils.test.js
@@ -60,26 +60,30 @@ describe('getColorRampCenterColor', () => {
 });
 
 describe('getColorRampStops', () => {
-  it('Should create color stops for color ramp', () => {
-    expect(getOrdinalColorRampStops('Blues')).toEqual([
+  it('Should create color stops for custom range', () => {
+    expect(getOrdinalColorRampStops('Blues', 0, 1000)).toEqual([
       0,
       '#f7faff',
-      0.125,
+      125,
       '#ddeaf7',
-      0.25,
+      250,
       '#c5daee',
-      0.375,
+      375,
       '#9dc9e0',
-      0.5,
+      500,
       '#6aadd5',
-      0.625,
+      625,
       '#4191c5',
-      0.75,
+      750,
       '#2070b4',
-      0.875,
+      875,
       '#072f6b',
     ]);
   });
+
+  it('Should snap to end of color stops for identical range', () => {
+    expect(getOrdinalColorRampStops('Blues', 23, 23)).toEqual([23, '#072f6b']);
+  });
 });
 
 describe('getLinearGradient', () => {

diff --git a/x-pack/legacy/plugins/maps/public/layers/styles/heatmap/heatmap_style.js b/x-pack/legacy/plugins/maps/public/layers/styles/heatmap/heatmap_style.js
@@ -14,6 +14,11 @@ import { getOrdinalColorRampStops } from '../color_utils';
 import { i18n } from '@kbn/i18n';
 import { EuiIcon } from '@elastic/eui';
 
+//The heatmap range chosen hear runs from 0 to 1. It is arbitrary.
+//Weighting is on the raw count/sum values.
+const MIN_RANGE = 0;
+const MAX_RANGE = 1;
+
 export class HeatmapStyle extends AbstractStyle {
   static type = LAYER_STYLE_TYPE.HEATMAP;
 
@@ -80,7 +85,7 @@ export class HeatmapStyle extends AbstractStyle {
 
     const { colorRampName } = this._descriptor;
     if (colorRampName && colorRampName !== DEFAULT_HEATMAP_COLOR_RAMP_NAME) {
-      const colorStops = getOrdinalColorRampStops(colorRampName);
+      const colorStops = getOrdinalColorRampStops(colorRampName, MIN_RANGE, MAX_RANGE);
       mbMap.setPaintProperty(layerId, 'heatmap-color', [
         'interpolate',
         ['linear'],

diff --git a/x-pack/legacy/plugins/maps/public/layers/styles/vector/properties/dynamic_color_property.js b/x-pack/legacy/plugins/maps/public/layers/styles/vector/properties/dynamic_color_property.js
@@ -5,8 +5,7 @@
  */
 
 import { DynamicStyleProperty } from './dynamic_style_property';
-import _ from 'lodash';
-import { getComputedFieldName, getOtherCategoryLabel } from '../style_util';
+import { getOtherCategoryLabel, makeMbClampedNumberExpression } from '../style_util';
 import { getOrdinalColorRampStops, getColorPalette } from '../../color_utils';
 import { ColorGradient } from '../../components/color_gradient';
 import React from 'react';
@@ -23,6 +22,7 @@ import { COLOR_MAP_TYPE } from '../../../../../common/constants';
 import { isCategoricalStopsInvalid } from '../components/color/color_stops_utils';
 
 const EMPTY_STOPS = { stops: [], defaultColor: null };
+const RGBA_0000 = 'rgba(0,0,0,0)';
 
 export class DynamicColorProperty extends DynamicStyleProperty {
   syncCircleColorWithMb(mbLayerId, mbMap, alpha) {
@@ -70,6 +70,17 @@ export class DynamicColorProperty extends DynamicStyleProperty {
     mbMap.setPaintProperty(mbLayerId, 'text-halo-color', color);
   }
 
+  supportsFieldMeta() {
+    if (!this.isComplete() || !this._field.supportsFieldMeta()) {
+      return false;
+    }
+
+    return (
+      (this.isCategorical() && !this._options.useCustomColorPalette) ||
+      (this.isOrdinal() && !this._options.useCustomColorRamp)
+    );
+  }
+
   isOrdinal() {
     return (
       typeof this._options.type === 'undefined' || this._options.type === COLOR_MAP_TYPE.ORDINAL
@@ -80,28 +91,20 @@ export class DynamicColorProperty extends DynamicStyleProperty {
     return this._options.type === COLOR_MAP_TYPE.CATEGORICAL;
   }
 
-  isCustomOrdinalColorRamp() {
-    return this._options.useCustomColorRamp;
-  }
-
   supportsMbFeatureState() {
     return true;
   }
 
-  isOrdinalScaled() {
-    return this.isOrdinal() && !this.isCustomOrdinalColorRamp();
-  }
-
   isOrdinalRanged() {
-    return this.isOrdinal() && !this.isCustomOrdinalColorRamp();
+    return this.isOrdinal() && !this._options.useCustomColorRamp;
   }
 
   hasOrdinalBreaks() {
-    return (this.isOrdinal() && this.isCustomOrdinalColorRamp()) || this.isCategorical();
+    return (this.isOrdinal() && this._options.useCustomColorRamp) || this.isCategorical();
   }
 
   _getMbColor() {
-    if (!_.get(this._options, 'field.name')) {
+    if (!this._field || !this._field.getName()) {
       return null;
     }
 
@@ -111,7 +114,7 @@ export class DynamicColorProperty extends DynamicStyleProperty {
   }
 
   _getOrdinalColorMbExpression() {
-    const targetName = getComputedFieldName(this._styleName, this._options.field.name);
+    const targetName = this._field.getName();
     if (this._options.useCustomColorRamp) {
       if (!this._options.customColorRamp || !this._options.customColorRamp.length) {
         // custom color ramp config is not complete
@@ -122,27 +125,44 @@ export class DynamicColorProperty extends DynamicStyleProperty {
         return [...accumulatedStops, nextStop.stop, nextStop.color];
       }, []);
       const firstStopValue = colorStops[0];
-      const lessThenFirstStopValue = firstStopValue - 1;
+      const lessThanFirstStopValue = firstStopValue - 1;
       return [
         'step',
-        ['coalesce', ['feature-state', targetName], lessThenFirstStopValue],
-        'rgba(0,0,0,0)', // MB will assign the base value to any features that is below the first stop value
+        ['coalesce', ['feature-state', targetName], lessThanFirstStopValue],
+        RGBA_0000, // MB will assign the base value to any features that is below the first stop value
         ...colorStops,
       ];
-    }
+    } else {
+      const rangeFieldMeta = this.getRangeFieldMeta();
+      if (!rangeFieldMeta) {
+        return null;
+      }
 
-    const colorStops = getOrdinalColorRampStops(this._options.color);
-    if (!colorStops) {
-      return null;
+      const colorStops = getOrdinalColorRampStops(
+        this._options.color,
+        rangeFieldMeta.min,
+        rangeFieldMeta.max
+      );
+      if (!colorStops) {
+        return null;
+      }
+
+      const lessThanFirstStopValue = rangeFieldMeta.min - 1;
+      return [
+        'interpolate',
+        ['linear'],
+        makeMbClampedNumberExpression({
+          minValue: rangeFieldMeta.min,
+          maxValue: rangeFieldMeta.max,
+          lookupFunction: 'feature-state',
+          fallback: lessThanFirstStopValue,
+          fieldName: targetName,
+        }),
+        lessThanFirstStopValue,
+        RGBA_0000,
+        ...colorStops,
+      ];
     }
-    return [
-      'interpolate',
-      ['linear'],
-      ['coalesce', ['feature-state', targetName], -1],
-      -1,
-      'rgba(0,0,0,0)',
-      ...colorStops,
-    ];
   }
 
   _getColorPaletteStops() {
@@ -220,7 +240,7 @@ export class DynamicColorProperty extends DynamicStyleProperty {
     }
 
     mbStops.push(defaultColor); //last color is default color
-    return ['match', ['to-string', ['get', this._options.field.name]], ...mbStops];
+    return ['match', ['to-string', ['get', this._field.getName()]], ...mbStops];
   }
 
   renderRangeLegendHeader() {