/*

 Copyright (C) 2014 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

  A view controller that uses a photo as a background image.

 */

#import "AAPLPhotoBackgroundViewController.h"

@interface AAPLPhotoBackgroundViewController ()

@property (nonatomic, strong) UIImageView *backgroundView;

@end

@implementation AAPLPhotoBackgroundViewController

- (void)loadView {

    UIView *containerView = [[UIView alloc] init];

    containerView.clipsToBounds = YES;

    self.backgroundView = [[UIImageView alloc] initWithImage:self.backgroundImage];

    [containerView addSubview:self.backgroundView];

    self.view = containerView;

}

- (void)viewWillLayoutSubviews {

    CGRect bounds = self.view.bounds;

    CGSize imageSize = self.backgroundView.image.size;

    CGFloat imageAspectRatio = imageSize.width / imageSize.height;

    CGFloat viewAspectRatio = CGRectGetWidth(bounds) / CGRectGetHeight(bounds);

    if (viewAspectRatio > imageAspectRatio) {

        // Let the background run off the top and bottom of the screen, so it fills the width

        CGSize scaledSize = CGSizeMake(CGRectGetWidth(bounds), CGRectGetWidth(bounds) / imageAspectRatio);

        self.backgroundView.frame = CGRectMake(0.0, (CGRectGetHeight(bounds) - scaledSize.height) / 2.0, scaledSize.width, scaledSize.height);

    } else {

        // Let the background run off the left and right of the screen, so it fills the height

        CGSize scaledSize = CGSizeMake(imageAspectRatio * CGRectGetHeight(bounds), CGRectGetHeight(bounds));

        self.backgroundView.frame = CGRectMake((CGRectGetWidth(bounds) - scaledSize.width) / 2.0, 0.0, scaledSize.width, scaledSize.height);

    }

}

- (void)setBackgroundImage:(UIImage *)backgroundImage {

    if (_backgroundImage != backgroundImage) {

        _backgroundImage = backgroundImage;

        self.backgroundView.image = backgroundImage;

    }

}

@end