react-native-indicator/lib/loader/PulseLoader.js

React Native Indicator Component

import React from 'react';
import PropTypes from 'prop-types';
import { Animated } from 'react-native';
import { Surface } from '@react-native-community/art';
import AnimatedCircle from '../animated/AnimatedCircle';
import { color } from '../const';

export default class PulseLoader extends React.PureComponent {
  static propTypes = {
    color: PropTypes.string,
    size: PropTypes.number,
    frequency: PropTypes.number,
  };

  static defaultProps = {
    color,
    size: 30,
    frequency: 1000,
  };

  state = {
    effect: new Animated.ValueXY({ x: 0, y: 1 }),
  };

  componentDidMount() {
    this._animation();
  }

  componentWillUnmount() {
    this.unmounted = true;
  }

  _animation = () => {
    Animated.parallel([
      Animated.timing(this.state.effect.x, {
        toValue: 1,
        duration: this.props.frequency,
        useNativeDriver: false,
      }),
      Animated.timing(this.state.effect.y, {
        toValue: 0.05,
        duration: this.props.frequency,
        useNativeDriver: false,
      }),
    ]).start(() => {
      if (!this.unmounted) {
        this.state.effect.setValue({ x: 0, y: 1 });
        this._animation();
      }
    });
  };

  render() {
    const { color, size } = this.props;
    return (
      <Surface width={size} height={size}>
        <AnimatedCircle
          radius={size}
          fill={color}
          scale={this.state.effect.x}
          opacity={this.state.effect.y}
          x={size / 2}
          y={size / 2}
        />
      </Surface>
    );
  }
}