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.
metersOnly	no	boolean	false	Hides feet scale
lineWidth	no	number	1	Width of vertical and horizontal lines
color	no	string	white	Color of labels and lines
fontSize	no	number	11	Size of the labels
limiterHeight	no	number	8	Height of the vertical lines

Todo

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