@elastic/ems-client/target/node/utils.js

JavaScript client library for the Elastic Maps Service

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.colorizeColor = colorizeColor;
exports.desaturateColor = desaturateColor;
exports.toAbsoluteUrl = toAbsoluteUrl;
var _chromaJs = _interopRequireDefault(require("chroma-js"));
function _interopRequireDefault(e) { return e && e.__esModule ? e : { default: e }; }
/*
 * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
 * or more contributor license agreements. Licensed under the Elastic License
 * 2.0; you may not use this file except in compliance with the Elastic License
 * 2.0.
 */

/**
 * Resolves a target URL path relative to the host.
 * This is specifically useed by the Kibana proxy re-routing.
 * It also handles trailing slashes in tileApiUrl and fileApiUrl parameters.
 */
function toAbsoluteUrl(host, path) {
  if (!host) {
    return path;
  }
  const hostEndWithSlash = host[host.length - 1] === '/';
  const pathStartsWithSlash = path[0] === '/';
  if (hostEndWithSlash === true && pathStartsWithSlash === true) {
    return host + path.slice(1);
  } else if (hostEndWithSlash !== pathStartsWithSlash) {
    return host + path;
  } else {
    return host + '/' + path;
  }
}

/*
Type with the possible ways to define a color in maplibre
*/

/*
A selection of the different maplibre-gl-js properties that refer to a color.
Taken from maplibre https://github.com/maplibre/maplibre-gl-js/blob/main/src/style-spec/types.g.ts
*/

/*
Function to transform a maplibre color definition by a given function.
*/
function transformColor(paintColor, func) {
  if (typeof paintColor == 'string') {
    const modifiedColor = func(paintColor);
    return `rgba(${modifiedColor.rgba().join(',')})`;
  } else if (typeof paintColor == 'object' && 'stops' in paintColor && Array.isArray(paintColor?.stops)) {
    const stops = paintColor['stops'].map(stop => {
      const newColor = transformColor(stop[1], func);
      return [stop[0], newColor];
    });
    const newPaintColor = Object.assign({}, paintColor, {
      stops
    });
    return newPaintColor;
  } else return paintColor;
}

/*
This is the function used to generate the current EMS desaturated roadmap
*/
function desaturateColor(paintColor) {
  return transformColor(paintColor, color => {
    return (0, _chromaJs.default)(color).desaturate(1.1).brighten(0.33);
  });
}

/*
Blends an original maplibre color definition with a destination
color. Accepts different blending modes and an additional `mix`
option that needs a percentage.

More details: 

https://gka.github.io/chroma.js/#chroma-blend
https://gka.github.io/chroma.js/#chroma-mix
*/
function colorizeColor(sourceColor, destColor, operation = 'screen', percentage = 0.5) {
  return transformColor(sourceColor, color => {
    if (operation !== 'mix') {
      return _chromaJs.default.blend((0, _chromaJs.default)(color), destColor, operation);
    } else {
      return _chromaJs.default.mix((0, _chromaJs.default)(color), destColor, percentage);
    }
  });
}