react-native-linear-gradient

react-native-linear-gradient

A <LinearGradient> component for react-native, as seen in react-native-login.

Add it to your project

iOS

1. Run npm install react-native-linear-gradient --save
2. Open your project in XCode, right click on Libraries and click Add Files to "Your Project Name" Look under node_modules/react-native-linear-gradient and add BVLinearGradient.xcodeproj. (Screenshot).
3. Add libBVLinearGradient.a to Build Phases -> Link Binary With Libraries (Screenshot).
4. Click on BVLinearGradient.xcodeproj in Libraries and go the Build Settings tab. Double click the text to the right of Header Search Paths and verify that it has $(SRCROOT)/../react-native/React - if it isn't, then add it. This is so XCode is able to find the headers that the BVLinearGradient source files are referring to by pointing to the header files installed within the react-native node_modules directory. (Screenshot).
5. Whenever you want to use it within React code now you can: var LinearGradient = require('react-native-linear-gradient');

If you're having trouble, you can point your package.json at github to see if the issue has been fixed. Simply change the dependency "react-native-linear-gradient": "brentvatne/react-native-linear-gradient", and then npm install

Android

1. in android/settings.gradle

     include ':app', ':react-native-linear-gradient'
     project(':react-native-linear-gradient').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-linear-gradient/android')
   

2. in android/app/build.gradle add:

   dependencies {
       ...
       compile project(':react-native-linear-gradient')
   }
   

3. and finally, in android/src/main/java/com/{YOUR_APP_NAME}/MainActivity.java add:

   ...
   import com.BV.LinearGradient.LinearGradientPackage; // <--- This!
   ...
   @Override
   protected void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       mReactRootView = new ReactRootView(this);
   
       mReactInstanceManager = ReactInstanceManager.builder()
               .setApplication(getApplication())
               .setBundleAssetName("index.android.bundle")
               .setJSMainModuleName("index.android")
               .addPackage(new MainReactPackage())
               .addPackage(new LinearGradientPackage()) // <---- and This!
               .setUseDeveloperSupport(BuildConfig.DEBUG)
               .setInitialLifecycleState(LifecycleState.RESUMED)
               .build();
   
       mReactRootView.startReactApplication(mReactInstanceManager, "SillyGoose", null);
   
       setContentView(mReactRootView);
   }
   

Examples

Simple

The following code will produce something like this:

// Within your render function
<LinearGradient colors={['#4c669f', '#3b5998', '#192f6a']} style={styles.linearGradient}>
  <Text style={styles.buttonText}>
    Sign in with Facebook
  </Text>
</LinearGradient>

// Later on in your styles..
var styles = StyleSheet.create({
  linearGradient: {
    flex: 1,
    paddingLeft: 15,
    paddingRight: 15,
    borderRadius: 5
  },
  buttonText: {
    fontSize: 18,
    fontFamily: 'Gill Sans',
    textAlign: 'center',
    margin: 10,
    color: '#ffffff',
  },
});

Additional props

You can also use start and end points, as well as specify the locations for the gradient color changes with the start, end and locations props:

<LinearGradient
  start={[0.0, 0.25]} end={[0.5, 1.0]}
  locations={[0,0.5,0.6]}
  colors={['#4c669f', '#3b5998', '#192f6a']}
  style={styles.linearGradient}>
  <Text style={styles.buttonText}>
    Sign in with Facebook
  </Text>
</LinearGradient>

Updating the values for fun

Check out [Examples/AnimatedGradient] (git clone this project, cd into it, npm install, open in XCode and run) to see how this is done:

This gif was created using licecap - a great piece of free OSS

An example app

You can see this component in action in brentvatne/react-native-login.