react-native-mapsforge-vtm

React Native components to build vector maps using Mapsforges fork of vtm. Offline rendering of OpenStreetMap data. Android only

Just some ideas in early development state. Do not use this for production! ... Well, you can use it, but things are changing!

Roadmap

Some things will change sometime soonish:

• Marker improvements: clustering and support for drag and drop.
• Changing the LayerPathSlopeGradient props, to be able to control the order of simplification and smoothing, and to apply those steps multiple times.
• Changing the LayerPathSlopeGradient component to support gradients as well for speed, elevation or any kind of data.
• Maybe merging the path components: LayerPathSlopeGradient and LayerPath.
• Hillshading improvements.
• Gesture events for MapContainer.
• New components for geometry like polygons and circles.
• New component LayerGroup.
• ...

Installation

# using npm
npm install react-native-mapsforge-vtm

# OR using Yarn
yarn add react-native-mapsforge-vtm

Usage

import React, {
  useEffect,
  useState,
} from 'react';
import {
  useWindowDimensions,
  SafeAreaView,
  ToastAndroid,
} from 'react-native';
import {
  MapContainer,
  LayerMapsforge,
  LayerBitmapTile,
  LayerMBTilesBitmap,
  LayerHillshading,
  LayerPathSlopeGradient,
  LayerScalebar,
  LayerMarker,
  Marker,
  useRenderStyleOptions,
} from 'react-native-mapsforge-vtm';

const App = () => {

  const { width, height } = useWindowDimensions();

  const [mapViewNativeNodeHandle, setMapViewNativeNodeHandle] = useState( null );     // To lift the mapViewNativeNodeHandle state into the app

  const [renderOverlayOptions, setRenderOverlayOptions] = useState( [] );

  const [renderOverlays, setRenderOverlays] = useState( [] );

  const [renderThemeOptions,setRenderThemeOptions] = useState( [
    ...[LayerMapsforge.BUILT_IN_THEMES].map( value => ( {
      label: value,
      value: value,
    } ) ),

    { label: 'Custom', value: '/storage/emulated/0/...' },  // Absolute path to xml render theme. Doesn't work with content uri.
  ] );

  const renderTheme = renderThemeOptions[renderThemeOptions.length-1];

  const {
    renderStyleDefaultId,
    renderStyleOptions,
  } = useRenderStyleOptions( ( {
    renderTheme,
    nativeNodeHandle: mapViewNativeNodeHandle,
  } ) );

  const [renderStyle, setRenderStyle] = useState( renderStyleDefaultId );

  useEffect( () => {
    if ( ! renderStyle && renderStyleDefaultId ) {
      setRenderStyle( renderStyleDefaultId );
    }

    if ( ! renderOverlayOptions.length ) {
      const renderStyleOptions_ = renderStyleOptions.find( opt => opt.value === renderStyle );
      if ( undefined !== renderStyleOptions_ ) {
        const newItems = Object.keys( renderStyleOptions_.options ).map( value => {
          return {
            value,
            label: renderStyleOptions_.options[value],
          };
        } );
        setRenderOverlayOptions( newItems );
      }
    }
  }, [renderStyle, renderStyleDefaultId] );

  return <SafeAreaView>

    <MapContainer
      nativeNodeHandle={ mapViewNativeNodeHandle /* Not possible to control this prop, it's just to lift the state up */ }
      setNativeNodeHandle={ setMapViewNativeNodeHandle }
      height={ height }
      width={ width /* defaults to full width */ }
      center={ {
        lng: -70.239,
        lat: -10.65,
      } }
      zoomLevel={ 12 }
      zoomMin={ 2 }
      zoomMax={ 20 }
      moveEnabled={ true }
      tiltEnabled={ false }
      rotationEnabled={ false }
      zoomEnabled={ true }
      hgtDirPath={ '/storage/emulated/0/...' /* If you need altitude data of map center in MapEvents. Absolute path or content uri to dem directory. Bad performance with content uri */ }
      responseInclude={ { center: 2, zoomLevel: 2 } }
      onPause={ response => console.log( 'lifecycle event', response ) }
      onResume={ response => console.log( 'lifecycle event', response ) }
      onMapEvent={ response => console.log( 'map move event', response ) }
    >

      <LayerBitmapTile
        url={ 'https://tile.openstreetmap.org/{Z}/{X}/{Y}.png' }
        cacheSize={ 10 * 1024 * 1024 }
      />

      <LayerMapsforge
        mapFile={ mapFile /* Absolute path or content uri to map file */ }
        renderTheme={ renderTheme }
        renderStyle={ renderStyle }
        renderOverlays={ renderOverlays }
      />

      <LayerMBTilesBitmap
        mapFile={ '/storage/emulated/0/...' /* Absolute path to bitmap mbtiles file. Doesn't work with content uri. */ }
      />

      <LayerHillshading
        hgtDirPath={ '/storage/emulated/0/...' /* Absolute path or content uri to dem directory. Bad performance with content uri */ }
        cacheSize={ 512 }
        zoomMin={ 2 }
        zoomMax={ 20 }
        shadingAlgorithm={ LayerHillshading.shadingAlgorithms.SIMPLE }
        magnitude={ 90 }
        shadingAlgorithmOptions={ {
            linearity: -1,
            scale: 1,
        } }
      />

      <LayerPathSlopeGradient
        responseInclude={ {
          coordinates: 1,             // include in response only on create.
          coordinatesSimplified: 2,   // include in response on create and on change.
        } }
        onCreate={ response => console.log( 'response', response ) }
        onRemove={ response => console.log( 'response', response ) }
        onChange={ response => console.log( 'response', response ) }
        slopeSimplificationTolerance={ 7 }
        flattenWindowSize={ 9 }
        strokeWidth={ 5 }
        slopeColors={ [
          [-25, '#000a70'],
          [-10, '#0000ff'],
          [-5, '#01c2ff'],
          [0, '#35fd2d'],
          [5, '#f9ff00'],
          [10, '#ff0000'],
          [25, '#810500'],
        ] }
        // positions={ [
        //     { lng: -76.813, lat: -11.813, alt: 4309 }
        //     // ...
        // ] }
        filePath={ '/storage/emulated/0/...' /* Absolute path or content uri to gpx file */ }
      />

      <LayerMarker>
        <Marker
          position={ lng: -76.813, lat: -11.813 }
          onPress={ response => {
            ToastAndroid.show( 'Marker pressed. index: ' + response.index + ' uuid: ' + response.uuid, ToastAndroid.SHORT );
          } }
          symbol={ {
            height: 100,
            textMargin: 20,
            textPositionY: 0,
            textStrokeWidth: 3,
            filePath={ '/storage/emulated/0/...' /* Absolute path or content uri to raster image or svg file */ }
            hotspotPlace: 'BOTTOM_CENTER',
            text: 'hello',
          } }
        />
        <Marker
          position={ lng: -75.814, lat: -12.274 }
          onLongPress={ response => {
            ToastAndroid.show( 'Marker long pressed. index: ' + response.index + ' uuid: ' + response.uuid, ToastAndroid.SHORT );
          } }
          symbol={ {
            width: 80,
            height: 80,
            textMargin: 20,
            textStrokeWidth: 3,
            textPositionY: 7,
            strokeColor: '#ff0000',
            fillColor: '#eeeeee',
            strokeWidth: 5,
            hotspotPlace: 'CENTER',
            text: 'hello',
          } }
        />
      </LayerMarker>

      <LayerScalebar/>

    </MapContainer>

  </SafeAreaView>;
};

Where to get maps?

Vector maps in mapsforge V5 format and xml render styles https://www.openandromaps.org/en/downloads.

Raster overview maps in MBtiles format https://www.openandromaps.org/en/downloads/general-maps.

Digital elevation Models, elevation data in hgt format at 3 arc second resolution https://viewfinderpanoramas.org/dem3.html

Contribution

Contributions welcome. You can report issues or suggest features. Help me coding, fork the repository and make pull requests.

License

MIT

Credits

• It's just a wrapper with limited features around Mapsforges fork of vtm. All credits to mapsforge and vtm!!!
• Dependencies of vtm: Game Controller Extension for libGDX, AndroidSVG, Simple Logging Facade for Java, OkHttp, Okio, Protocol Buffers - Google's data interchange format, MapBox Vector Tile - Java
• JTS Topology Suite
• Most of the hillshading code is copied from mapsforge
• To retrieve the elevation for certain coordinates, most code is copied from mapsforge and Java OpenStreetMap Editor - Plugins - ElevationProfile
• Android GPX Parser
• Simplification of a 2D-polyline or a 3D-polyline
• For smoothing data: Savitzky–Golay filter in Java
• Always helpful: Lodash
• To help limiting the amount of data that flows through the bottleneck between react and java: queue-promise
• Keep a Changelog helps maintaining a CHANGELOG.md.
• Made with create-react-native-library