README

react-native-heat-map

A component for React Native that can be rendered on top or underneath your <View/>s with transparency. If you don't feel like using a native library, you might be interested in react-native-simpleheat.

Android	iOS

The native Android solution is implemented using simpleheat as the development reference. On iOS, the heatmap is presented using the performant LFHeatMap as a CocoaPods dependeny. This is not a <MapView/>; but it can be overlaid one.

🚀 Getting started

Using npm:

$ npm install @cawfree/react-native-heat-map --save

Using yarn:

yarn add @cawfree/react-native-heat-map

🤖 Mostly automatic installation

If you're running react-native at any version less than 0.60.0, you'll need to manually link the library to your project:

$ react-native link react-native-heat-map

🔩 Manual installation

iOS

In XCode, in the project navigator, right click Libraries ➜ Add Files to [your project's name]
Go to node_modules ➜ react-native-heat-map and add HeatMap.xcodeproj
In XCode, in the project navigator, select your project. Add libHeatMap.a to your project's Build Phases ➜ Link Binary With Libraries
Run your project (Cmd+R)<

Android

Open up android/app/src/main/java/[...]/MainApplication.java

Add import io.github.cawfree.HeatMapPackage; to the imports at the top of the file
Add new HeatMapPackage() to the list returned by the getPackages() method

Append the following lines to android/settings.gradle:

include ':react-native-heat-map'
project(':react-native-heat-map').projectDir = new File(rootProject.projectDir, 	'../node_modules/react-native-heat-map/android')

Insert the following lines inside the dependencies block in android/app/build.gradle:
```
  compile project(':react-native-heat-map')
```

✍️ Example

There are two main modes the <HeatMap/> can operate in. You can either specify cartesian (2D) co-ordinates:

import HeatMap from 'react-native-heat-map';

export default () => (
  <HeatMap
    pointerEvents="box-only"
    style={{
      flex: 1,
    }}
    data={[
      [
        100, // x
        100, // y
        20   // intensity
      ],
    ]}
  />
);

Alternatively, you can pass a react-native-maps-compatible region prop to process your data through a Web Mercator Projection:

import HeatMap from 'react-native-heat-map';

export default () => (
  <HeatMap
    pointerEvents="box-only"
    style={{
      flex: 1,
    }}
    data={[
      [
        -3.0118499, // longitude
        53.4139281, // latitude
        20   // intensity
      ],
    ]}
    region={{
      longitude: -3.0118499,
      latitude: 53.4139281,
      latitudeDelta: 0.2,
      longitudeDelta: 0.2,
    }}
  />
);

For performance, instead of using setState to update the <HeatMap />, you can choose to setNativeProps directly.

Check out the complete example code.

📌 Props

Prop	Type	Default	Required
max	number	10	No
data	array	[]	No
minOpacity	number	0.05	No
alpha	number	1.0	No
region	shape	null	No

✌️ License

MIT

Usage no npm install needed!