README.md

react-native-scale-bar

Scale bar for MapView in React Native. Works with Mapbox and Google Map.

Installation

npm install --save react-native-scale-bar

Usage

import React, { Component } from "react";
import Mapbox from "@mapbox/react-native-mapbox-gl";
import ScaleBar from "react-native-scale-bar";
import debounce from "lodash.debounce";

(...)

onUserLocationUpdate(location) {
  const latitude = location.coords.latitude;
  this.setState({latitude});
}

async handleMapChange() {
  const zoom = await this._map.getZoom();
  this.setState({zoom});
}

(...)

<Mapbox.MapView
  ref={c => (this._map = c)}
  onRegionDidChange={() => this.handleMapChange()}
  onRegionIsChanging={debounce(() => this.handleMapChange(), 200)}
  onRegionWillChange={() => this.handleMapChange()}
  onUserLocationUpdate={this.onUserLocationUpdate}
  (...)
/>

<ScaleBar zoom={this.state.zoom} latitude={this.state.latitude}/>

Properties

Prop	Required	Type	Default	Description
zoom	yes	number	-	Pass the zoom level to the component to adjust the scale bar.
latitude	no	number	48.8187	Use the latitude to adjust the scale bar precision.
left	no	number	10	Padding with left border of the screen.
bottom	no	number	32	Padding with bottom of the screen.

Todo

• Option to place the scale bar anywhere on the screen
• Add imperial units