Dynamic Keyboards and Views ObjC

file.h

#import <UIKit/UIKit.h>

@interface SignUpViewController : UIViewController <UITextFieldDelegate> {
    
    BOOL isLastTextField;

    CGFloat adjustmentOffset;
    CGFloat mainViewHeight;
    CGFloat subViewHeight;
    CGFloat keyboardY;
    NSInteger textFieldY;
    CGRect textFieldFrame;
}

@property (retain, nonatomic) IBOutlet UITextField *email;
@property (retain, nonatomic) IBOutlet UITextField *password;
@property (retain, nonatomic) IBOutlet UITextField *passwordConfirm;

@property (assign, nonatomic) IBOutlet UIView *textFieldView;

@end

file.m

#define KEYBOARD_HEIGHT 216

@interface SignUpViewController ()

@end

@implementation SignUpViewController
@synthesize email, password, passwordConfirm, textFieldView;

#pragma mark - Keyboard Delegates

-(void) keyboardDidShow: (NSNotification *)notif
{
    // Grab view height dynamically (needed for iPhone 4 and 5)
    mainViewHeight = [[UIScreen mainScreen] bounds].size.height;
    keyboardY = mainViewHeight - KEYBOARD_HEIGHT;
}

-(void) keyboardDidHide: (NSNotification *)notif
{
    if(isLastTextField){
        // slide view down when hidden
        [UIView animateWithDuration:0.2
    animations:^{
        [[self textFieldView] setTransform:CGAffineTransformIdentity];
    
    }];
    }
        // Reset offset
        adjustmentOffset = 0;
}

- (void)textFieldDidBeginEditing:(UITextField *)textField
{
    // Use "next" until final field "done"
    if (textField != ([textfieldsArr objectAtIndex:[textfieldsArr count]-1])) {
        textField.returnKeyType = UIReturnKeyNext;
    }
    
    textFieldFrame = textField.frame;
    CGPoint textFieldLocation = textFieldFrame.origin;
    textFieldY = textFieldLocation.y;

    // The keyboard hit the middle of the textfield so I adjusted by 35px
    if(fabsf(keyboardY - textFieldY) < 35){ 
        adjustmentOffset -= fabsf(keyboardY - textFieldY);
    }
    
    // slide view up when keyboard shown
    [UIView animateWithDuration:0.4
                     animations:^{
                         [[self textFieldView] setTransform:CGAffineTransformMakeTranslation(0, adjustmentOffset)];
                     }];
}

- (void)textFieldDidEndEditing:(UITextField *)textField
{
    // reset scrollview once keyboard hides on last field
    if(textField == [textfieldsArr objectAtIndex:[textfieldsArr count]-1]){
        isLastTextField = YES;
    }else{
        isLastTextField = NO;
    }
}

-(BOOL)textFieldShouldReturn:(UITextField*)textField;
{
    for(int i=0; i<[textfieldsArr count]-1; i++){
        
        if(textField == [textfieldsArr objectAtIndex:i]){
            // resign keyboard to current textfield
            [textField resignFirstResponder];
            
            // make the next textfield firstResponder
            if(i <= [textfieldsArr count]){
                
                // else just become firstresponder
                [[textfieldsArr objectAtIndex:i+1] becomeFirstResponder];
            }
        }
        // reaches "done"
        [textField resignFirstResponder]; 
    }
    
    return NO; // We do not want UITextField to insert line-breaks.
}