gistfile1.txt

#pragma mark - Keyboard Appearance

- (void)keyboardWillShow:(NSNotification *)notification
{
    NSDictionary* info = [notification userInfo];
    CGRect keyboardFrame = [notification.userInfo[UIKeyboardFrameEndUserInfoKey] CGRectValue];
    keyboardFrame = [self.view.window convertRect:keyboardFrame toView:self.view];
    
    CGRect intersectRect = CGRectIntersection(self.view.frame, keyboardFrame);
    
    self.toolbarBottomContraint.constant = -intersectRect.size.height;
    [self.view animateLayoutIfNeededWithKeyboardUserInfo:info];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    self.toolbarBottomContraint.constant = 0;
    [self.view animateLayoutIfNeededWithKeyboardUserInfo:notification.userInfo];
}

@end

@implementation UIView (LayoutAnimation)

- (void)animateLayoutIfNeededWithKeyboardUserInfo:(NSDictionary *)info
{
    [UIView animateWithDuration:[[info objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue]
                          delay:0
                        options:(UIViewAnimationOptions)([[info objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue] << 16)
                     animations:^{
                         [self layoutIfNeeded];
                     }
                     completion:nil];
}

@end