rs-react-native-map-clustering/dist/lib/utils.js

React Native Map Clustering both for Android and iOS with TypeScript support

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.createBoundsChecker = exports.processInChunks = exports.windowMarkers = void 0;
/**
 * Utility for handling large marker datasets with virtual windowing
 * Only processes markers that are within the visible region or just outside it
 */
const windowMarkers = (markers, region, bufferFactor = 0.5 // Buffer factor determines how much outside the visible region we should process
) => {
    if (!markers.length)
        return [];
    // Calculate region boundaries with buffer
    const latBuffer = region.latitudeDelta * bufferFactor;
    const lngBuffer = region.longitudeDelta * bufferFactor;
    const minLat = region.latitude - region.latitudeDelta / 2 - latBuffer;
    const maxLat = region.latitude + region.latitudeDelta / 2 + latBuffer;
    const minLng = region.longitude - region.longitudeDelta / 2 - lngBuffer;
    const maxLng = region.longitude + region.longitudeDelta / 2 + lngBuffer;
    // Filter markers to only include ones in the viewable region plus buffer
    return markers.filter((marker) => {
        // Always include clusters as they represent multiple points
        if (marker.properties.cluster)
            return true;
        const lat = marker.geometry.coordinates[1];
        const lng = marker.geometry.coordinates[0];
        return lat >= minLat && lat <= maxLat && lng >= minLng && lng <= maxLng;
    });
};
exports.windowMarkers = windowMarkers;
/**
 * Chunk processing for very large marker arrays
 * Processes large arrays in smaller chunks to avoid UI blocking
 */
const processInChunks = (items, processor, chunkSize = 100) => {
    return new Promise((resolve) => {
        const result = [];
        let index = 0;
        function processNextChunk() {
            const chunk = items.slice(index, index + chunkSize);
            index += chunkSize;
            if (!chunk.length) {
                resolve(result);
                return;
            }
            // Process this chunk
            const chunkResult = chunk.map(processor);
            result.push(...chunkResult);
            // Schedule next chunk with a small delay to allow UI updates
            if (index < items.length) {
                setTimeout(processNextChunk, 0);
            }
            else {
                resolve(result);
            }
        }
        processNextChunk();
    });
};
exports.processInChunks = processInChunks;
/**
 * Returns a function that can be used to efficiently test if a point (marker)
 * is within the current visible map bounds
 */
const createBoundsChecker = (region, bufferFactor = 0.5) => {
    const latBuffer = region.latitudeDelta * bufferFactor;
    const lngBuffer = region.longitudeDelta * bufferFactor;
    const minLat = region.latitude - region.latitudeDelta / 2 - latBuffer;
    const maxLat = region.latitude + region.latitudeDelta / 2 + latBuffer;
    const minLng = region.longitude - region.longitudeDelta / 2 - lngBuffer;
    const maxLng = region.longitude + region.longitudeDelta / 2 + lngBuffer;
    return (lat, lng) => lat >= minLat && lat <= maxLat && lng >= minLng && lng <= maxLng;
};
exports.createBoundsChecker = createBoundsChecker;