@datacamp/react-native-linear-gradient

react-native-linear-gradient

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

Version 2.0 supports react-native >= 0.40.0

Add it to your project

You can try linking the project automatically:

$ react-native link

or do it manually as described below:

iOS

• Run npm install react-native-linear-gradient --save

Then either:

Cocoapods

add the following line to your Podfile:

pod 'React', :path => '../node_modules/react-native'
pod 'BVLinearGradient', :path => '../node_modules/react-native-linear-gradient'

or:

Manually

1. 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).
2. Add libBVLinearGradient.a to Build Phases -> Link Binary With Libraries (Screenshot).
3. 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).

Then:

• Whenever you want to use it within React code now you can: import LinearGradient from '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": "react-native-community/react-native-linear-gradient",

to get the data right from github instead of npm and then npm install

For instance the podspec file does not contain the right data (author attributes etc..) in npm while it does in the github repo.

Android

1. in android/settings.gradle

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

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

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

1. and finally, in android/src/main/java/com/{YOUR_APP_NAME}/MainActivity.java for react-native < 0.29, or android/src/main/java/com/{YOUR_APP_NAME}/MainApplication.java for react-native >= 0.29 add:

//...
import com.BV.LinearGradient.LinearGradientPackage; // <--- This!
//...
@Override
protected List<ReactPackage> getPackages() {
  return Arrays.<ReactPackage>asList(
    new MainReactPackage(),
    new LinearGradientPackage() // <---- and This!
  );
}

Examples

Simple

The following code will produce something like this:

import LinearGradient from 'react-native-linear-gradient';

// 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',
    backgroundColor: 'transparent',
  },
});

Additional props

In addition to regular View props, you can also provide additional props to customize your gradient look:

colors

An array of at least two color values that represent gradient colors. Example: ['red', 'blue'] sets gradient from red to blue.

start

An optional object of the following type: { x: number, y: number }. Coordinates declare the position that the gradient starts at, as a fraction of the overall size of the gradient, starting from the top left corner. Example: { x: 0.1, y: 0.1 } means that the gradient will start 10% from the top and 10% from the left.

end

Same as start, but for the end of the gradient.

locations

An optional array of numbers defining the location of each gradient color stop, mapping to the color with the same index in colors prop. Example: [0.1, 0.75, 1] means that first color will take 0% - 10%, second color will take 10% - 75% and finally third color will occupy 75% - 100%.

<LinearGradient
  start={{x: 0.0, y: 0.25}} end={{x: 0.5, y: 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.

License

License is MIT