How to autolayout this scroll view? - ios

Question

I am working with this app: http://www.raywenderlich.com/13541/how-to-create-an-app-like-instagram-with-a-web-service-backend-part-22 there is a screen called stream screen that lists jpegs in a UIScrollView named list view. The apps was made for iPhone originally so the author has the storyboards set up for iPhone. How can I resize the list view to fit both iPhones and iPads while scaling the contentt?
Additional info: the storyboard has one uiscrollview. Right now i have the size set to 1192 height 1080 width because I am testing on an iPad and this are the previous dimensions I've used successfully. However when the screen itself loads , it only takes up about a 3rd of the width of the total UIScrollView.
update
//photoscreen.h
//
#import <UIKit/UIKit.h>
//1 layout config
#define kThumbSide 90
#define kPadding 10
//2 define the thumb delegate protocol
#protocol PhotoViewDelegate <NSObject>
-(void)didSelectPhoto:(id)sender;
#end
//3 define the thumb view interface
#interface PhotoView : UIButton
{
}
#property (assign, nonatomic) id<PhotoViewDelegate> delegate;
-(id)initWithIndex:(int)i andData:(NSDictionary*)data;
#end
//this code is from photoview,which acts as a delegate for stream screen.m likewise, it formats the streams quality such as picture spacing
#import "PhotoView.h"
#import "API.h"
#implementation PhotoView
#synthesize delegate;
-(id)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
// Initialization code
}
return self;
}
-(id)initWithIndex:(int)i andData:(NSDictionary*)data {
self = [super init];
if (self !=nil) {
//initialize
self.tag = [[data objectForKey:#"IdPhoto"] intValue];
int row = i/3;
int col = i % 3;
self.frame = CGRectMake(1.5*kPadding+col*(kThumbSide+kPadding), 1.5*kPadding+row*(kThumbSide+kPadding), kThumbSide, kThumbSide);
self.backgroundColor = [UIColor grayColor];
//add the photo caption
UILabel* caption = [[UILabel alloc] initWithFrame:CGRectMake(0, kThumbSide-16, kThumbSide, 16)];
caption.backgroundColor = [UIColor blackColor];
caption.textColor = [UIColor whiteColor];
caption.textAlignment = UITextAlignmentCenter;
caption.font = [UIFont systemFontOfSize:12];
caption.text = [NSString stringWithFormat:#"#%#",[data objectForKey:#"username"]];
[self addSubview: caption];
//add touch event
[self addTarget:delegate action:#selector(didSelectPhoto:) forControlEvents:UIControlEventTouchUpInside];
//load the image
API* api = [API sharedInstance];
int IdPhoto = [[data objectForKey:#"IdPhoto"] intValue];
NSURL* imageURL = [api urlForImageWithId:[NSNumber numberWithInt: IdPhoto] isThumb:YES];
AFImageRequestOperation* imageOperation = [AFImageRequestOperation imageRequestOperationWithRequest: [NSURLRequest requestWithURL:imageURL] success:^(UIImage *image) {
//create an image view, add it to the view
UIImageView* thumbView = [[UIImageView alloc] initWithImage: image];
thumbView.frame = CGRectMake(0,0,90,90);
thumbView.contentMode = UIViewContentModeScaleAspectFit;
[self insertSubview: thumbView belowSubview: caption];
}];
NSOperationQueue* queue = [[NSOperationQueue alloc] init];
[queue addOperation:imageOperation];
}
return self;
}
#end