Root view controller is built in code - Wont resize for iPad - objective-c

Question

Im trying to convert my iphone app to ipad, all good until my root view controller. Its been built in code and no matter what I do I cant resize it/centre it. I have no nib for my Home page. Autoresize masks doesn't do anything, adding an iPad nib does nothing despite best efforts but continue to present the iphone screen in top left, and using if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) loads a a blank black iPad screen. I really dont know what to to now. If I set my screen elements to initWithFrame:[[UIScreen mainScreen] bounds]]; the artwork is distorted as its overstretched.
// Create the main view
UIView *mainView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
mainView.backgroundColor = [UIColor blackColor];
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
UIImageView *textureBg = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 768.0f, 1024.0f)];
textureBg.image = [UIImage imageNamed:#"BgTexture"];
[textureBg addSubview:textureBg];
}
else {
// Add textured background
UIImageView *textureBg = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320.0f, 1024.0f)];
textureBg.image = [UIImage imageNamed:#"BgTexture"];
[textureBg addSubview:textureBg];
}
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
UIImageView *clipBg = [[UIImageView alloc] initWithFrame:CGRectMake(7.0f, 6.0f, 605.0f, 865.0f )];
clipBg.image = [UIImage imageNamed:#"BgHomeNew2"];
clipBg.userInteractionEnabled = YES;
}
else {
// Add clipboard background
UIImageView *clipBg = [[UIImageView alloc] initWithFrame:CGRectMake(7.0f, 6.0f, 305.0f, 465.0f )];
clipBg.image = [UIImage imageNamed:#"BgHomeNew2"];
clipBg.userInteractionEnabled = YES;
//[clipBg setAutoresizingMask:(UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleRightMargin|UIViewAutoresizingFlexibleTopMargin )];
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
// Add about button to clipbg
UIButton *aboutButton = [UIButton buttonWithType:UIButtonTypeCustom];
aboutButton.frame = CGRectMake(240.0f, 90.0f, 31.0f, 33.0f);
[aboutButton setImage:[UIImage imageNamed:#"LabelButton"] forState:UIControlStateNormal];
[aboutButton addTarget:self action:#selector(aboutButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[aboutButton addSubview:aboutButton];
}
else {
// Add about button to clipbg
UIButton *aboutButton = [UIButton buttonWithType:UIButtonTypeCustom];
aboutButton.frame = CGRectMake(240.0f, 90.0f, 31.0f, 33.0f);
[aboutButton setImage:[UIImage imageNamed:#"LabelButton"] forState:UIControlStateNormal];
[aboutButton addTarget:self action:#selector(aboutButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
[aboutButton addSubview:aboutButton];
}
How do I make an ipad view, for a universal app, where the root view controller is built in code? Im even open to the idea of simply centering the iphone screen in the middle of the ipad screen but as autoresing wont work its just stuck in the top left. This would be 2 mins in IB!
To summarise why wont the following code move the image to the center of the iPad screen?
UIImageView *clipBg = [[UIImageView alloc] initWithFrame:CGRectMake(7.0f, 6.0f, 305.0f, 465.0f )];
clipBg.image = [UIImage imageNamed:#"BgHomeNew2"];
clipBg.userInteractionEnabled = YES;
[clipBg setAutoresizingMask:(UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin)];
EDIT
Really dont know what im missing here, been on this a whole day now, Cant seem to add a xib retrospectively to an iphone screen built in code, so I will settle for centring objects in the middle of the screen when ipad is used rather than stuck in the top left all the time. That dosent work either.

Answer 1

Ok sorted it
Ive finally maged to add xibs now so I can adjust as necessary, I couldn't initialise the xibs before because I had missed this line of code in my rootview contoller
- (id)init
{
[[NSBundle mainBundle] loadNibNamed:#"ICHomeController" owner:self options:nil];