objective-c : adjust UITextView size and scrolling position

snippet.m

//adjust UITextView size and scrolling position

- (void)viewDidLoad
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    [super viewDidLoad];
    
    [self registerForKeyboardNotifications];
}


- (void)viewWillDisappear:(BOOL)animated
{
    if (debug==1) {NSLog(@"Running %@ '%@'", self.class, NSStringFromSelector(_cmd));}
    
    [super viewWillDisappear:animated];
    
    [[NSNotificationCenter defaultCenter] removeObserver:self]; //키보드 옵저버 해제
}


#pragma mark - Keyboard Notifications

// Call this method somewhere in your view controller setup code.
- (void)registerForKeyboardNotifications
{
    //키보드 팝업 옵저버 (키보드 팝업 시 텍스트 뷰 사이즈 조절)
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillShow:)
                                                 name:UIKeyboardWillShowNotification object:self.view.window];
    
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:)
                                                 name:UIKeyboardWillHideNotification object:self.view.window];
    
}


- (void)updateNoteTextViewSize {
    
    UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
    CGFloat keyboardHeight = UIInterfaceOrientationIsLandscape(orientation) ? _keyboardSize.width : _keyboardSize.height;
    self.noteTextView.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height - keyboardHeight);
}


// Called when the UIKeyboardDidShowNotification is sent.
- (void)keyboardWillShow:(NSNotification *)notification
{
    NSDictionary *userInfo = [notification userInfo];
    _keyboardSize = [[userInfo objectForKey:UIKeyboardFrameBeginUserInfoKey] CGRectValue].size;
    
    //노트필드 사이즈 조정
    double uDelayInSeconds = 0.4;
    dispatch_time_t uPopTime = dispatch_time(DISPATCH_TIME_NOW, uDelayInSeconds * NSEC_PER_SEC);
    dispatch_after(uPopTime, dispatch_get_main_queue(), ^(void){
        
        [UIView animateWithDuration:0.3 animations:^{
            [self updateNoteTextViewSize];
        }];
    });
}


// Called when the UIKeyboardWillHideNotification is sent
- (void)keyboardWillHide:(NSNotification*)aNotification
{
    _keyboardSize = CGSizeMake(0.0, 0.0);
    
    self.noteTextView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0); //노트필드 컨텐츠 인 셋 (top, left, bottom, right)
    self.noteTextView.scrollIndicatorInsets = UIEdgeInsetsMake(0, 0, 0, 0); //노트필드 스크롤 인디케이터 인 셋
    
    [UIView animateWithDuration:0.3 animations:^{
        [self updateNoteTextViewSize];
    }];
}