Correct keyboard frame

UIKeyboardFrameEndUserInfoKey

- (void)keyboardWillShow:(NSNotification *)notification {
    CGRect keyboardFrame = [[notification userInfo][UIKeyboardFrameEndUserInfoKey] CGRectValue];
    self.textViewBottomConstraint.constant = keyboardFrame.size.height - self.tabBarController.tabBar.frame.size.height;

    UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(singleTap:)];
    [self.view addGestureRecognizer:singleTap];

    [UIView animateWithDuration:[notification.userInfo[UIKeyboardAnimationDurationUserInfoKey] doubleValue]
                          delay:0
                        options:(UIViewAnimationOptions) [[notification userInfo][UIKeyboardAnimationCurveUserInfoKey] integerValue]
                     animations:^{
                         [self.view layoutIfNeeded];
                         [self scrollTableToBottom:NO];
                     } completion:nil];
}