componentDidMount() {
  this.keyboardDidShow = Keyboard.addListener(
   'keyboardDidShow',
   this.keyboardDidShow
  );
  this.keyboardWillShow = Keyboard.addListener(
  'keyboardWillShow',
   this.keyboardWillShow
);
this.keyboardWillHide = Keyboard.addListener(
  'keyboardWillHide',
  this.keyboardWillHide
   );
}
keyboardDidShow = () => {
  this.setState({ searchBarFocused: true });
};
keyboardWillShow = () => {
  this.setState({ searchBarFocused: true });
};
keyboardWillHide = () => {
  this.setState({ searchBarFocused: false });
};