Attaching a UIToolbar to the iPhone’s Keyboard – Extended

- (void)keyboardWillShow:(NSNotification *)notification {
    double animationDuration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationCurve animationCurve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue];
    
    CGRect keyboardBounds = [(NSValue *)[[notification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue];
    
    [UIView beginAnimations:@"showKeyboardAnimation" context:nil];
    
    [UIView setAnimationCurve:animationCurve];
    [UIView setAnimationDuration:animationDuration];
    
    self.view.frame = CGRectMake(self.view.frame.origin.x,
                                 self.view.frame.origin.y,
                                 self.view.frame.size.width,
                                 self.view.frame.size.height - keyboardBounds.size.height);
 
    CGRect textFieldFrame = _textField.frame;
    textFieldFrame.size.width = keyboardBounds.size.width - 36.0 - 50.0; // Done button is 50 pixels wide, 3 times 12 pixels space
    _textField.frame = textFieldFrame;
    _toolbar.items = [NSArray arrayWithObjects:_textFieldBarButtonItem,_flexibleSpaceBarButtonItem,_doneBarButtonItem,nil];
    [UIView commitAnimations];
}
- (void)keyboardWillHide:(NSNotification *)notification {
    double animationDuration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    UIViewAnimationCurve animationCurve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue];
    
    CGRect keyboardBounds = [(NSValue *)[[notification userInfo] objectForKey:UIKeyboardBoundsUserInfoKey] CGRectValue];
    
    [UIView beginAnimations:@"hideKeyboardAnimation" context:nil];
    
    [UIView setAnimationCurve:animationCurve];
    [UIView setAnimationDuration:animationDuration];
    
    self.view.frame = CGRectMake(self.view.frame.origin.x,
                                 self.view.frame.origin.y,
                                 self.view.frame.size.width,
                                 self.view.frame.size.height + keyboardBounds.size.height);
    CGRect textFieldFrame = _textField.frame;
    textFieldFrame.size.width = keyboardBounds.size.width - 24.0; // 12 pixels space to either side
    _textField.frame = textFieldFrame;
    _toolbar.items = [NSArray arrayWithObject:_textFieldBarButtonItem];
    
    [UIView commitAnimations];
}