intro.js

runIntroAnimation = async () => {
    await this.setState({
      timer: this.state.timer + 1.5,
      scaleA: new Animated.Value(1),
      opacityA: new Animated.Value(1),
      scaleB: new Animated.Value(1),
      opacityB: new Animated.Value(1)
    });
    let { scaleA, scaleB, opacityA, opacityB } = this.state;
    Animated.stagger(500, [
      Animated.parallel([
        Animated.timing(opacityA, {
          toValue: 0.25,
          duration: 750
        }),

        Animated.timing(scaleA, {
          toValue: 1.5,
          duration: 750
        })
      ]),
      Animated.parallel([
        Animated.timing(opacityB, {
          toValue: 0.25,
          duration: 750
        }),
        Animated.timing(scaleB, {
          toValue: 1.5,
          duration: 750
        })
      ])
    ]).start(() =>
      this.state.timer >= 3 ? this.props.done() : this.runIntroAnimation()
    );
  };