Object-C iOS

Slide UIView up and down, when the keyboard appears & disappears

- (void)viewDidLoad
{
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(keyboardWillShow:)
     name:UIKeyboardWillShowNotification
     object:nil];
    [[NSNotificationCenter defaultCenter]
     addObserver:self
     selector:@selector(keyboardWillHide:)
     name:UIKeyboardWillHideNotification
     object:nil];
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

- (void)keyboardWillShow:(NSNotification *)notification {
    CGRect start, end;
    
    // position of keyboard before animation
    [[[notification userInfo] objectForKey:UIKeyboardFrameBeginUserInfoKey] getValue:&start];
    // and after..
    [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] getValue:&end];
  
    double duration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    int curve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue];
    
    // slide view up..
    [UIView beginAnimations:@"foo" context:nil];
    [UIView setAnimationDuration:duration];
    [UIView setAnimationCurve:curve];
    self.view.frame = CGRectMake(0, -end.size.width, 480, 320);
    [UIView commitAnimations];
}

- (void) keyboardWillHide:(NSNotification *)notification {
    double duration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    int curve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue];
    
    // slide view down
    [UIView beginAnimations:@"foo" context:nil];
    [UIView setAnimationDuration:duration];
    [UIView setAnimationCurve:curve];
    self.view.frame = CGRectMake(0, 0, 480, 320);
    [UIView commitAnimations];
}