random-streetview/src/index.js

Finds a random valid StreetView location in a given polygon.

import StreetView from "./StreetView";
import Google from "./Google.js";
import EventEmitter from 'events';

class RandomStreetView extends EventEmitter {
    constructor() {
        super();
        this._streetView = new StreetView();
        this._streetView.on('tiles', tiles => this.emit('tiles', tiles));
        this.endZoom = 14;
        this.type = 'sv';
        this.distribution = 'weighted';
    }

    setHighCpuUsage() {
        this._streetView.slowCpu = false;
    }

    setLowCpuUsage() {
        this._streetView.slowCpu = true;
    }

    async setParameters({
                            polygon = false,
                            enableCaching = true,
                            endZoom = 14,
                            cacheKey = false,
                            type = 'sv',
                            distribution = 'weighted',
                            google = false,
                        }) {
        if (!['sv', 'photo', 'both'].includes(type))
            console.error("Type parameter should be either 'sv', 'photo', or 'both'");
        if (!['weighted', 'uniform'].includes(distribution))
            console.error("Distribution parameter should be either 'uniform' or 'weighted'");
        if (endZoom < 11)
            console.warn("endZoom parameter should not be less than 11");
        if (endZoom > 22)
            console.error("endZoom can't be higher than 22");
        if (!google) {
            await Google.wait();
            google = Google;
        }
        if (polygon instanceof Array) {
            let paths = polygon.map(path => path.map(([lat, lng]) => new google.maps.LatLng(lat, lng)));
            polygon = new google.maps.Polygon({
                paths: paths,
                strokeColor: "#00ff7a",
                strokeOpacity: 0.8,
                strokeWeight: 2,
                fillColor: "#00ff7a",
                fillOpacity: 0.35,
                draggable: false,
                clickable: false,
            });
        }
        if (!cacheKey && enableCaching && polygon) {
            console.log(polygon)
            cacheKey = '';
            polygon.getPaths().forEach(p => p.forEach(c => cacheKey += c.lat().toString() + c.lng()));
        }

        this._streetView.setParameters(polygon, enableCaching, cacheKey, google);
        this.endZoom = endZoom;
        this.type = type;
        this.distribution = distribution;
    }

    async getRandomLocations(nLocations, onLocation = () => 0) {
        let get = async () => {
            let location = await this.getRandomLocation();
            onLocation(location);
            return location;
        };
        let tasks = [];
        for (let i = 0; i < nLocations; i++)
            tasks.push(new Promise(resolve => get().then(resolve)));
        return await Promise.all(tasks);
    }

    async getRandomLocation() {
        if (!this._streetView.google) {
            await Google.wait();
            this._streetView.google = Google;
        }
        let location = await this._streetView.randomValidLocation({
            endZoom: this.endZoom,
            distribution: this.distribution,
            type: this.type
        });
        if (location === false)
            return false;
        return [location.lat(), location.lng()];
    }
}

export default new RandomStreetView();