Synchronizing rotation animation between the keyboard and the attached view - Part 2

synchronizing-rotation-animation-part-2.m

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];
    [[NSNotificationCenter defaultCenter]
            addObserver:self
            selector:@selector(keyboardWillChangeFrame:)
            name:UIKeyboardWillChangeFrameNotification object:nil];
}

- (void)viewDidDisappear:(BOOL)animated {
    [super viewDidDisappear:animated];
    [[NSNotificationCenter defaultCenter] removeObserver:self name:UIKeyboardWillChangeFrameNotification object:nil];
}

// called on iOS-7 and below on step: #1
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];
    self.animatingRotation = YES;
}

// called on iOS-7 and below on step: #3
- (void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
    [super willAnimateRotationToInterfaceOrientation:toInterfaceOrientation duration:duration];
}

// called on iOS-7 and below on step: #5
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
    [super didRotateFromInterfaceOrientation:fromInterfaceOrientation];
    self.animatingRotation = NO;
}
// called on iOS-8 on step: #1
- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
    [coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        // called on step: #2
        self.animationDuration = [context transitionDuration];
        self.animationCurve = [context completionCurve];
        self.animatingRotation = YES;
    } completion:^(id<UIViewControllerTransitionCoordinatorContext> context) {
        // called on step: #5
        self.animatingRotation = NO;
    }];
}

// called on iOS-7 and below on steps: #2, #4
// called on iOS-8 on steps: #3, #4, #6, #7
- (void)keyboardWillChangeFrame:(NSNotification*)notification {
    [self adjustViewForKeyboardNotification:notification];
}

- (void)adjustViewForKeyboardNotification:(NSNotification *)notification {
    NSDictionary *notificationInfo = [notification userInfo];
    
    // Get the end frame of the keyboard in screen coordinates.
    CGRect finalKeyboardFrame = [[notificationInfo objectForKey:UIKeyboardFrameEndUserInfoKey] CGRectValue];

    // Convert the finalKeyboardFrame to view coordinates to take into account any rotation
    // factors applied to the window’s contents as a result of interface orientation changes.
    finalKeyboardFrame = [self.view convertRect:finalKeyboardFrame fromView:self.view.window];
    
    if (!self.animatingRotation) {
        // Get the animation curve and duration frp, keyboard notification info
        UIViewAnimationCurve animationCurve = (UIViewAnimationCurve) [[notificationInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] integerValue];
        NSTimeInterval animationDuration = [[notificationInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] doubleValue];
        // On iOS8 if the animationDuration is 0,
        // then the quicktype panel is being shown/hidden and the code executed here will be animated automatically
        if (animationDuration == 0) {
            [self adjustViewsForKeyboardFrame:finalKeyboardFrame];
        } else {
            [self adjustViewsForKeyboardFrame:finalKeyboardFrame withAnimationDuration:animationDuration animationCurve:animationCurve];
        }
    } else {
        if ([UIView areAnimationsEnabled]) {
            [self adjustViewsForKeyboardFrame:finalKeyboardFrame];
        } else {
            [UIView setAnimationsEnabled:YES];
            [self adjustViewsForKeyboardFrame:finalKeyboardFrame withAnimationDuration:self.animationDuration animationCurve:self.animationCurve];
            [UIView setAnimationsEnabled:NO];
        }
    }
}

- (void)adjustViewsForKeyboardFrame:(CGRect)keyboardFrame withAnimationDuration:(NSTimeInterval)animationDuration animationCurve:(UIViewAnimationCurve)animationCurve {
    // Animate view synchronously with the appearance of the keyboard.
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:animationDuration];
    [UIView setAnimationCurve:animationCurve];
    [UIView setAnimationBeginsFromCurrentState:YES];
    [self adjustViewsForKeyboardFrame:keyboardFrame];
    [UIView commitAnimations];
}

- (void)adjustViewsForKeyboardFrame:(CGRect)keyboardFrame {
    // Calculate new position of the view
    CGRect frame = self.floatingView.frame;
    frame.origin.y = frame.origin.y - frame.size.height;
    self.floatingView.frame = frame;
    
    // Update other related views, for example the height of a tableView
    CGRect tableViewFrame = self.tableView.frame;
    tableViewFrame.size.height = frame.origin.y;
    self.tableView.frame = tableViewFrame;
}

Great blog post. Thanks for posting the code!

I think there is a typo on line 95:
frame.origin.y = frame.origin.y - frame.size.height;

should be
frame.origin.y = keyboardFrame.origin.y - frame.size.height;

right?