// NSNotificationCenter の通知を利用

// UIKeyboardDidChangeFrameNotification
// キーボードのサイズが変更する時
// キーボードが出るたびに毎回呼ばれる

@implementation ViewController

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];

    // キーボードのサイズが変化するとき
    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(keyboarDidChangeFrame:)
                                                 name:UIKeyboardDidChangeFrameNotification
                                               object:nil];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];

    [[NSNotificationCenter defaultCenter] removeObserver:self
                                                    name:UIKeyboardDidChangeFrameNotification
                                                  object:nil];
}

// キーボードのサイズが変化するとき
- (void)keyboarDidChangeFrame:(NSNotificationCenter*)notification
{
    UIInterfaceOrientation orientation = self.interfaceOrientation;
    NSString *interfaceOrientation = [self getOrientation:orientation];
    NSLogE(@"現在の画面の向き: %@", interfaceOrientation);
}

- (NSString*)getOrientation:(UIInterfaceOrientation)interfaceOrientation
{
    NSString *str;

    if(interfaceOrientation == UIInterfaceOrientationPortrait){
        str = @"portrait";
    } else if(interfaceOrientation == UIInterfaceOrientationLandscapeLeft){
        str = @"landscape left";
    } else if(interfaceOrientation == UIInterfaceOrientationPortraitUpsideDown){
        str = @"upsidedown";
    } else if(interfaceOrientation == UIInterfaceOrientationLandscapeRight){
        str = @"landscape right";
    }

    NSLogE(@"現在の画面の向き: %@", str);

    return str;
}

@end