map_marker_cache 1.0.1

A Flutter library for caching custom Google Maps marker icons locally using ObjectBox, optimizing performance and enabling offline support.

map_marker_cache

map_marker_cache is a Flutter library designed to optimize the loading of custom marker icons for Google Maps by caching BitmapDescriptor objects locally using ObjectBox. This significantly reduces the performance overhead associated with converting images (like SVGs) to BitmapDescriptor at runtime, especially for applications with many markers or offline capabilities.

Features

• Performance Optimization: Reduces marker rendering time by caching BitmapDescriptor objects.
• Offline Support: Stores converted image data locally, enabling instant loading even without an internet connection.
• Simple API: Provides an easy-to-use API for Flutter developers integrating with Google Maps.
• SVG to Uint8List Conversion: Built-in utility for converting SVG assets to Uint8List for storage.

Installation

Add this to your package's pubspec.yaml file:

dependencies:
  map_marker_cache: ^1.0.0 # Replace with the latest version

Then, install it by running:

flutter pub get

Usage

1. Initialize the Cache

First, get an instance of MapMarkerCache and initialize it. This should be done once when your application starts.

import 'package:map_marker_cache/map_marker_cache.dart';

// Initialize MapMarkerCache (singleton)
await MapMarkerCache.instance.init();

2. Get or Create a Marker Icon

Use the getOrBuildAndCacheMarkerIcon method to get a BitmapDescriptor. If the icon is already in the cache, it will be loaded instantly. If not, it will be created from the asset, cached, and then returned.

import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:map_marker_cache/map_marker_cache.dart';

// Get a cached BitmapDescriptor
final BitmapDescriptor markerIcon = await MapMarkerCache.instance.getOrBuildAndCacheMarkerIcon(
  assetPath: 'assets/your_marker.svg', // Path to your SVG asset
  devicePixelRatio: MediaQuery.of(context).devicePixelRatio, // For correct scaling
  // Optional: A unique key for your icon. If not provided, a key is generated from the assetPath and size.
  // key: 'unique_marker_id',
  // Optional: Specify the desired size.
  // size: const Size(90, 90),
);

// Use the BitmapDescriptor with a Google Maps Marker
Marker(
  markerId: const MarkerId('marker_1'),
  position: const LatLng(45.521563, -122.677433),
  icon: markerIcon,
);

Running the Example

To see map_marker_cache in action, you can run the example project. The example now demonstrates the caching mechanism by displaying icons loaded from cache versus icons loaded normally (without cache) side-by-side, without requiring a Google Maps API key.

1. Navigate to the example/ directory:

   cd example
   

2. Get the project dependencies:

   flutter pub get
   

3. Run the example application:

   flutter run
   

   This will launch a simple Flutter application displaying cached and non-cached marker icons.