The (not so) ultimate UIScrollView keyboard appearance and disappearance implementation

keyboard.m

//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
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//

- (void)keyboardWillShowNotification:(NSNotification *)notification
{
    UIView *view = self.view;
    
    CGRect keyboardFrame = [[[notification userInfo] objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];
    keyboardFrame = [view convertRect:keyboardFrame fromView:self.view.window];
    
    // according to Apple docs you can't rely on the origin of the keyboard frame as it will be animating
    // so we can just work it out manually
    keyboardFrame.origin.x = 0;
    keyboardFrame.origin.y = CGRectGetHeight([UIScreen mainScreen].bounds) - CGRectGetHeight(keyboardFrame);
    
    // don't adjust the offsets if the keyboard is now obscuring the view
    if (!CGRectIntersectsRect(keyboardFrame, view.frame)) {
        return;
    }
    
    CGFloat duration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    NSInteger animationCurve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
    CGRect intersection = CGRectIntersection(keyboardFrame, view.frame);
    
    UIEdgeInsets insets = self.scrollView.contentInset;
    insets.bottom = intersection.size.height;
    
    [UIView animateWithDuration:duration delay:0.0f options:animationCurve animations:^{
        self.scrollView.contentInset = insets;
        self.scrollView.scrollIndicatorInsets = insets;
    } completion:nil];
}


- (void)keyboardWillHideNotification:(NSNotification *)notification
{
    CGFloat duration = [[[notification userInfo] objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
    NSInteger animationCurve = [[[notification userInfo] objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
    
    UIEdgeInsets insets = self.scrollView.contentInset;
    insets.bottom = 0;
    
    [UIView animateWithDuration:duration delay:0.0f options:animationCurve animations:^{
        self.scrollView.contentInset = insets;
        self.scrollView.scrollIndicatorInsets = self.scrollView.contentInset;
    } completion:nil];
}

Don't use this, it doesn't work, use http://stackoverflow.com/a/19660499/248848 instead