leaksample_fixed.js

class Composer extends Component {
  state = { showAccessory: false };

  componentDidMount() {
    this.keyboardDidShowListener = Keyboard.addListener('keyboardDidShow', () =>
      this.setState({ showAccessory: true })
    );
    this.keyboardDidHideListener = Keyboard.addListener('keyboardDidHide', () =>
      this.setState({ showAccessory: false })
    );
  }

  componentWillUnmount() {
    this.keyboardDidShowListener.remove();
    this.keyboardDidHideListener.remove();
  }

  render() {
    return (
      <View>
        <EditTextComponent />
        (this.state.showAccessory && <AccessoryView />)
      </View>
    );
  }
}}