flutter_ek_osm_map 1.0.3

A Dart implementation of Leaflet to provide a Map widget for Flutter apps

flutter_ek_osm_map

A Dart implementation of Flutter Map for Flutter apps and added Polygon Tap.

Installation

Add flutter_ek_osm_map to your pubspec:

dependencies:
  flutter_ek_osm_map: any # or the latest version on Pub

Android

Configure your app to use the INTERNET permission in the manifest file located in <project root>/android/app/src/main/AndroidManifest.xml:

<uses-permission android:name="android.permission.INTERNET" />

Usage

Configure the map using MapOptions and layer options:

Widget build(BuildContext context) {
  return FlutterMap(
    options: MapOptions(
      center: LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    layers: [
      TileLayerOptions(
        urlTemplate: "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
        subdomains: ['a', 'b', 'c'],
        attributionBuilder: (_) {
          return Text("© OpenStreetMap contributors");
        },
      ),
      MarkerLayerOptions(
        markers: [
          Marker(
            width: 80.0,
            height: 80.0,
            point: LatLng(51.5, -0.09),
            builder: (ctx) =>
                Container(
                  child: FlutterLogo(),
                ),
          ),
        ],
      ),
    ],
  );
}

Alternatively, initialize the map by specifying bounds instead of center and zoom.

MapOptions
(
bounds: LatLngBounds
(
LatLng
(58.8,
6.1
)
,
LatLng
(59,
6.2
)
)
,
boundsOptions: FitBoundsOptions
(
padding: EdgeInsets.all(8.0
)
)
,
)
,

Azure Maps provider

To configure Azure Maps, use the following MapOptions and layer options:

Widget build(BuildContext context) {
  return new FlutterMap(
    options: new MapOptions(
      center: new LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    layers: [
      new TileLayerOptions(
        urlTemplate: "https://atlas.microsoft.com/map/tile/png?api-version=1&layer=basic&style=main&tileSize=256&view=Auto&zoom={z}&x={x}&y={y}&subscription-key={subscriptionKey}",
        additionalOptions: {
          'subscriptionKey': '<YOUR_AZURE_MAPS_SUBSCRIPTON_KEY>'
        },
      ),
      new MarkerLayerOptions(
        markers: [
          new Marker(
            width: 80.0,
            height: 80.0,
            point: new LatLng(51.5, -0.09),
            builder: (ctx) =>
            new Container(
              child: new FlutterLogo(),
            ),
          ),
        ],
      ),
    ],
  );
}

To use Azure Maps, [set up an account and get a subscription key][azure-maps-instructions]

Open Street Map provider

Configure the map to use [Open Street Map][open-street-map] by using the following MapOptions and layer options:

Widget build(BuildContext context) {
  return new FlutterMap(
    options: new MapOptions(
      center: new LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    layers: [
      new TileLayerOptions(
          urlTemplate: "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
          subdomains: ['a', 'b', 'c']
      ),
      new MarkerLayerOptions(
        markers: [
          new Marker(
            width: 80.0,
            height: 80.0,
            point: new LatLng(51.5, -0.09),
            builder: (ctx) =>
            new Container(
              child: new FlutterLogo(),
            ),
          ),
        ],
      ),
    ],
  );
}

Widget Layers

Use the new way to create layers (compatible with previous version)

Widget build(BuildContext context) {
  return FlutterMap(
    options: MapOptions(
      center: LatLng(51.5, -0.09),
      zoom: 13.0,
    ),
    layers: [
      MarkerLayerOptions(
        markers: [
          Marker(
            width: 80.0,
            height: 80.0,
            point: LatLng(51.5, -0.09),
            builder: (ctx) =>
                Container(
                  child: FlutterLogo(),
                ),
          ),
        ],
      ),
    ],
    children: <Widget>[
      TileLayerWidget(options: TileLayerOptions(
          urlTemplate: "https://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png",
          subdomains: ['a', 'b', 'c']
      )),
      MarkerLayerWidget(options: MarkerLayerOptions(
        markers: [
          Marker(
            width: 80.0,
            height: 80.0,
            point: LatLng(51.5, -0.09),
            builder: (ctx) =>
                Container(
                  child: FlutterLogo(),
                ),
          ),
        ],
      )),
    ],
  );
}

Custom CRS

By default flutter_ek_osm_map supports only WGS84 (EPSG:4326) and Google Mercator (EPSG:3857) projections. The [proj4dart][proj4dart] package provides additional reference systems ( CRS).

To use proj4dart, first define a custom CRS:

var resolutions = <double>[32768, 16384, 8192, 4096, 2048, 1024, 512, 256, 128];
var maxZoom = (resolutions.length - 1).toDouble();

var epsg3413CRS = Proj4Crs.fromFactory(
  code: 'EPSG:3413',
  proj4Projection:
  proj4.Projection.add('EPSG:3413',
      '+proj=stere +lat_0=90 +lat_ts=70 +lon_0=-45 +k=1 +x_0=0 +y_0=0 +datum=WGS84 +units=m +no_defs'),
  resolutions: resolutions,
);

Then use the custom CRS in the map layer and in WMS layers:

child: FlutterMap
(
options: MapOptions
(
// Set the map's CRS
crs: epsg3413CRS,center: LatLng
(65.05166470332148,
-
19.171744826394896
)
,
maxZoom: maxZoom,)
,
layers: [
TileLayerOptions
(
wmsOptions: WMSTileLayerOptions
(
// Set the WMS layer's CRS too
crs: epsg3413CRS,baseUrl: '
https://www.gebco.net/data_and_products/gebco_web_services/north_polar_view_wms/mapserv?
'
,
layers: ['gebco_north_polar_view'],
),
),
]
,
);

For more details, see the [custom CRS README][custom-crs-readme].

Run the example

See the example/ folder for a working example app.

To run it, in a terminal cd into the folder. Then execute ulimit -S -n 2048 ([ref][ulimit-comment]). Then execute flutter run with a running emulator.

Downloading and caching offline maps

This section provides an overview of the available caching tile providers. If you would like to provide preconfigured and prepackaged map tiles to your app users, see the 'Preconfigured Offline Maps' section below.

The two available options included in flutter_ek_osm_map

1. Use NetworkImage by using NonCachingNetworkTileProvider

Whilst the name might make you think differently, it is designed to prevent you from using it and expecting it to cache; because it doesn't.

The FlutterMap NonCachingNetworkTileProvider implementaion uses NetworkImage which should cache images in memory until the app restart (through Image.network). See the [Image.network][Image.network] docs and [NetworkImage][NetworkImage-caching] docs for more details.

2. Using the cached_network_image dependency

This dependency has an ImageProvider that caches images to disk, which means the cache persists through an app restart. You'll need to include the package in your pubspec.yaml.

Create your own provider using the code below:

import 'package:cached_network_image/cached_network_image.dart';

class CachedTileProvider extends TileProvider {
  const CachedTileProvider();

  @override
  ImageProvider getImage(Coords<num> coords, TileLayerOptions options) {
    return CachedNetworkImageProvider(
      getTileUrl(coords, options),
      //Now you can set options that determine how the image gets cached via whichever plugin you use.
    );
  }
}

Then, add the CachedTileProvider TileProvider to the appropriate TileLayerOptions:

TileLayerOptions
(
urlTemplate: '
https://example.com/{x}/{y}/{z}
'
,
tileProvider: const CachedTileProvider()
)

Offline Maps using TileMill

This section provides instructions for preconfigured and prepackaged offline maps. To see how to setup caching and downloading, see the 'Dynamically Downloading & Caching Offline Maps' section above.

This guide uses an open source program called [TileMill][tilemill-homepage].

First, [install TileMill][install-tilemill] on your machine. Then, follow [these instructions][tilemill].

Once you have your map exported to .mbtiles, you can use [mbtilesToPng][mbTilesToPngs] to unpack into /{z}/{x}/{y}.png.

Move this to assets folder and add the appropriate asset directories to pubspec.yaml. Minimum required fields for this solution are:

Widget build(ctx) {
  return FlutterMap(
    options: MapOptions(
      center: LatLng(56.704173, 11.543808),
      zoom: 13.0,
      swPanBoundary: LatLng(56.6877, 11.5089),
      nePanBoundary: LatLng(56.7378, 11.6644),
    ),
    layers: [
      TileLayerOptions(
        tileProvider: AssetTileProvider(),
        urlTemplate: "assets/offlineMap/{z}/{x}/{y}.png",
      ),
    ],
  );
}

A missing asset error will be thrown if the PanBoundaries are outside the offline map boundary.

See the flutter_ek_osm_map_example/ folder for a working example.

See also FileTileProvider(), which loads tiles from the filesystem.