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, azure-maps-instructions
Open Street Map provider
Configure the map to use 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
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
.
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
(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 docs and
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-homepage
.
First, install-tilemill
on your machine. Then,
follow tilemill
.
Once you have your map exported to .mbtiles
, you can use
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.