Air-Quality-Web/client_src/js/MarkerGenerator.mjs

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JavaScript
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"use strict";
import chroma from 'chroma-js';
import marker_svg from '../marker-embed.svg';
import gradients from './Gradients.mjs';
class MarkerGenerator {
constructor() {
}
marker_default() {
return marker_svg.replace("{{colour_a}}", "#1975c8")
.replace("{{colour_b}}", "#5ea6d5")
.replace("{{colour_dark}}", "#2e6d99");
}
marker(value, type) {
let col = this.get_colour(value, type);
let result = marker_svg.replace(/\{\{colour_a\}\}/g, col.darken(0.25).hex())
.replace(/\{\{colour_b\}\}/g, col.brighten(0.25).hex())
.replace(/\{\{colour_dark\}\}/g, col.darken(1))
.replace(/\{\{id_grad\}\}/g, `marker-grad-${btoa(`${type}-${value}`).replace(/\+/g, "-").replace(/\//g, "_")}`);
return result;
}
/**
* Fetches the colour for a given value of a given type.
* Currently a gradient is not used - i.e. a value is coloured according to
* the last threshold it crossed in the associated gradient definition.
* TODO: Calculate the gradient instead.
* @param {number} value The value to calculate the colour for.
* @param {string} type The type of measurement value we're working with. Determines the gradient to use.
* @return {chroma} The calculated colour.
*/
get_colour(value, type) {
if(typeof gradients[type] == "undefined") {
console.warn(`[MarkerGenerator] Warning: Unknown gradient type '${type}', using unknown instead.`);
type = "unknown";
}
return gradients[type].chroma(value);
}
}
export default MarkerGenerator;