Offline

The OfflineManager provides a set of tools to manage the cache and handle offline maps. It enables users to download and interact with map data in areas with limited or no internet access. Here, we’ll cover key features, usage concepts, and API details for OfflineManager.

The download manager needs to be created asynchronous by using OfflineManager.createInstance(). You can store the instance for later use.

Future<OfflineManager> futureManager = OfflineManager.createInstance();

Don't forget to call manager.dispose() when you no longer need it. You can do this for example in the dispose override of a flutter widget:

@override
void dispose() {
  manager.dispose();
  super.dispose();
}

Downloading Map Regions

Using OfflineManager, you can bulk-download specific map regions for offline access.

Future<void> downloadMyMap() async {
  final stream = await manager.downloadRegion(
    minZoom: 10,
    maxZoom: 14,
    bounds: LngLatBounds(/* ... */),
    mapStyleUrl: '...',
    pixelDensity: 1,
  );
  await for (final update in stream) {
    if (update.downloadCompleted) {
      print('region downloaded: ${update.region}');
    } else {
      print(
        '${update.loadedTiles} / ${update.totalTiles} '
            '(${((update.progress ?? 0) * 100).toStringAsFixed(0)}%)',
      );
    }
  }
}

Managing Offline Regions

After regions are downloaded, they can be managed using methods to list, merge, or retrieve specific region details:

Listing Offline Regions

Get a list of all downloaded regions for management or display purposes by using manager.listOfflineRegions().

Retrieving a Specific Region

Fetch a region’s details with manager.getOfflineRegion(regionId: 1), which is useful for managing or displaying region-specific data.

Merging Regions

Merge an offline region from an MBTiles database into the MapLibre tile cache by using manager.mergeOfflineRegions(path: 'path/to/mbtiles'). Ensure that the app has permission to read the directory.

Cache Management

There are mutliple methods to manage and control the cache, ensuring efficient use of storage. Head over to the API docs to learn more.